Release Notes

download PDF
Red Hat Ceph Storage 3.1

Release notes for Red Hat Ceph Storage 3.1

Red Hat Ceph Storage Documentation Team


The Release Notes document describes the major features and enhancements implemented in Red Hat Ceph Storage in a particular release. The document also includes known issues and bug fixes.

Chapter 1. Introduction

Red Hat Ceph Storage is a massively scalable, open, software-defined storage platform that combines the most stable version of the Ceph storage system with a Ceph management platform, deployment utilities, and support services.

The Red Hat Ceph Storage documentation is available at

Chapter 2. Acknowledgments

Red Hat Ceph Storage version 3.1 contains many contributions from the Red Hat Ceph Storage team. Additionally, the Ceph project is seeing amazing growth in the quality and quantity of contributions from individuals and organizations in the Ceph community. We would like to thank all members of the Red Hat Ceph Storage team, all of the individual contributors in the Ceph community, and additionally (but not limited to) the contributions from organizations such as:

  • Intel
  • Fujitsu
  • UnitedStack
  • Yahoo
  • UbuntuKylin
  • Mellanox
  • CERN
  • Deutsche Telekom
  • Mirantis
  • SanDisk
  • SUSE

Chapter 3. New features

This section lists all major updates, enhancements, and new features introduced in this release of Red Hat Ceph Storage.

3.1. Ceph Ansible

Support for iSCSI gateway upgrades through rolling updates

Previously, when using a Ceph iSCSI gateway node, iscsi-gws could not be updated by ceph-ansible during a rolling upgrade. With this update to Red Hat Ceph Storage, ceph-ansible now supports upgrading iscsi-gws using the rolling_update.yml Ansible playbook.

Support NVMe based bucket index pools

Previously, configuring Ceph to optimize storage on high speed NVMe or SATA SSDs when using Object Gateway was a completely manual process which required complicated LVM configuration.

With this release, the ceph-ansible package provides two new Ansible playbooks that facilitate setting up SSD storage using LVM to optimize performance when using Object Gateway. See the Using NVMe with LVM Optimally chapter in the Red Hat Ceph Storage Object Gateway for Production Guide for more information.

3.2. Ceph Dashboard

Installation of Red Hat Ceph Storage Dashboard using the ansible user

Previously, installing Red Hat Ceph Storage Dashboard (cephmetrics) with Ansible required root access. Traditionally, Ansible uses passwordless ssh and sudo with a regular user to install and make changes to systems. In this release, the Red Hat Ceph Storage Dashboard can be installed with ansible using a regular user. For more information on the Red Hat Ceph Storage Dashboard, see the Administration Guide.

The Red Hat Ceph Storage Dashboard displays the amount of used and available RAM on the storage cluster nodes

Previously, there was no way to view the actual memory usage on cluster nodes from the Red Hat Ceph Storage Dashboard. With this update to Red Hat Ceph Storage, a memory usage graph has been added to the OSD Node Detail dashboard.

The Prometheus plugin for the Red Hat Ceph Storage Dashboard

Previously, the Red Hat Ceph Storage Dashboard used collectd and Graphite for gathering and reporting on Ceph metrics. With this release, Prometheus is now used for data gathering and reporting, and provides querying capabilities. Also, Prometheus is much less resource intensive. See the Red Hat Ceph Storage Administration Guide for more details on the Prometheus plugin.

The Red Hat Ceph Storage Dashboard supports OSDs provisioned by the ceph-volume utility

In this release, an update to the Red Hat Ceph Storage Dashboard adds support for displaying information on ceph-volume provisioned OSDs.

3.3. CephFS

More accurate CephFS free space information

The CephFS kernel client now reports the same, more accurate free space information as the fuse client via the df command.

3.4. iSCSI Gateway

The max_data_area_mb option is configurable per-LUN

Previously, the amount of memory the kernel used to pass SCSI command data to tcmu-runner was hard coded to 8MB. The hard coded limit was too small for many workloads and resulted in reduced throughput and/or TASK SET FULL errors filling initiator side logs. This can now be configured by setting the max_data_area_mb value with gwcli. Information on the new setting and command can be found in the Red Hat Ceph Storage Block Device Guide.

iSCSI gateway command-line utility (gwcli) supports snapshot create, delete, and rollback capabilities

Previously, to manage the snapshots of RBD-backed LUN images the rbd command line utility was utilized for this purpose. The gwcli utility now includes built-in support for managing LUN snapshots. With this release, all snapshot related operations can now be handled directly within the gwcli utility.

Disabling CHAP for iSCSI gateway authentication

Previously, CHAP authentication was required when using the Ceph iSCSI gateway. With this release, disabling CHAP authentication can be configured with the gwcli utility or with Ceph Ansible. However, mixing clients with CHAP enabled and disabled is not supported. All clients must either have CHAP enabled or disabled. If enabled, clients might have different CHAP credentials.

3.5. Object Gateway

Improved Swift container ACL conformance has been added

Previously, Red Hat Ceph Storage did not support certain ACL use cases, including setting of container ACLs whose subject is a Keystone project/tenant.

With this update of Ceph, many Swift container ACLs which were previously unsupported are now supported.

Improvements to radosgw-admin sync status commands

With this update of Red Hat Ceph Storage a new radosgw-admin bucket sync status command has been added, as well as improvements to the existing sync status and data sync status commands.

These changes will make it easier to inspect the progress of multisite syncs.

Automated trimming of bucket index logs

When multisite sync is used, all changes are logged in the bucket index. These logs can grow excessively large. They also are no longer needed once they have been processed by all peer zones.

With this update of Red Hat Ceph Storage, the bucket index logs are automatically trimmed and do not grow beyond a reasonable size.

Admin socket command to invalidate cache

Two new admin socket commands to manipulate the cache were added to the radosgw-admin tool.

The cache erase <objectname> command flushes the given object from the cache.

The cache zap command erases the entire cache.

These commands can be used to help debug problems with the cache or provide a temporary workaround when an RGW node is holding stale information in the cache. Administrators can now flush any and all objects from the cache.

New administrative sockets added for the radosgw-admin command to view the Object Gateway cache

Two new administrative sockets were added to the radosgw-admin command to view the contents of the Ceph Object Gateway cache.

The cache list [string] sub-command lists all objects in the cache. If the optional string is provided, it only matches those objects containing the string.

The cache inspect <objectname> sub-command prints detailed information about the object.

These commands can be used to help debug caching problems on any Ceph Object Gateway node.

Implementation of partial order bucket/container listing

Previously, list bucket/container operations always returned elements in a sorted order. This has high overhead with sharded bucket indexes. Some protocols can tolerate receiving elements in arbitrary order so this is now allowed. An example curl command using this new feature:

curl GET http://server:8080/tb1?allow-unordered=True

With this update to Red Hat Ceph Storage, unordered listing via Swift and S3 is supported.

Asynchronous Garbage Collection

An asynchronous mechanism for executing the Ceph Object Gateway garbage collection using the librados APIs has been introduced. The original garbage collection mechanism serialized all processing, and lagged behind applications in specific workloads. Garbage collection performance has been significantly improved, and can be tuned to specific site requirements.

Relaxed region constraint enforcement

In Red Hat Ceph Storage 3.x when using s3cmd and option --region with a zonegroup that does not exist an InvalidLocationConstraint error will be generated. This did not occur in Ceph 2.x because it did not have strict checking on the region. With this update Ceph 3.1 adds a new rgw_relaxed_region_enforcement boolean option to enable relaxed (non-enforcement of region constraint) behavior backward compatible with Ceph 2.x. The option defaults to False.

Default rgw_thread_pool_size value change to 512

The default rgw_thread_pool_size value changed from 100 to 512. This change accommodates larger workloads. Decrease this value for smaller workloads.

Increased the default value for the objecter_inflight_ops option

The default value for the objecter_inflight_ops option was changed from 1024 to 24576. The original default value was insufficient to support a typical Object Gateway workload. With this enhancement, larger workloads are supported by default.

3.6. Object Gateway Multisite

Add option --trim-delay-ms in radosgw-admin sync error trim command - to limit the frequency of osd ops

A "trim delay" option has been added to the "radosgw-admin sync error trim" command in Ceph Object Gateway multisite. Previously, many OMAP keys could have been deleted by the full operation, leading to potential for impact on client workload. With the new option, trimming can be requested with low client workload impact.

3.7. Packages

Rebase Ceph to version 12.2.5

Red Hat Ceph Storage 3.1 is now based on upstream Ceph Luminous 12.2.5.

3.8. RADOS

Warnings about objects with too many omap entries

With this update to Red Hat Ceph Storage warnings are displayed about pools which contain large omap objects. They can be seen in the output of ceph health detail. Information about the large objects in the pool are printed in the cluster logs. The settings which control when the warnings are printed are osd_deep_scrub_large_omap_object_key_threshold and osd_deep_scrub_large_omap_object_value_sum_threshold.

The filestore_merge_threshold option default has changed

Subdirectory merging has been disabled by default. The default value of the filestore_merge_threshold option has changed to -10 from 10. It has been observed to improve performance significantly on larger systems with a minimal performance impact to smaller systems. To take advantage of this performance increase set the expected-num-objects value when creating new data pools. See the Object Gateway for Production Guide for more information.

Logs now list PGs that are splitting

The FileStore split log now shows splitting placement groups (PGs).

Chapter 4. Bug fixes

This section describes bugs fixed in this release of Red Hat Ceph Storage that have significant impact on users. In addition, it includes descriptions of fixed known issues from previous versions.

4.1. Ceph Ansible

Containerized OSDs start after reboot

Previously, in a containerized environment, after rebooting Ceph storage nodes some OSDs might not have started. This was due to a race condition. The race condition was resolved and now all OSD nodes start properly after a reboot.


Ceph Ansible no longer overwrites existing OSD partitions

On a OSD node reboot, it is possible that disk devices will get a different device path. For example, prior to restarting the OSD node, /dev/sda was an OSD, but after a reboot, the same OSD is now /dev/sdb. Previously, if no "ceph" partition was found on the disk, it was a valid OSD disk. With this release, if any partition is found on the disk, then the disk will not be used as an OSD.


Ansible no longer creates unused systemd unit files

Previously, when installing the Ceph Object Gateway by using the ceph-ansible utility, ceph-ansible created systemd unit files for the Ceph Object Gateway host corresponding to all Object Gateway instances located on other hosts. However, the only unit file that was active was the one that corresponded to the hostname of the Ceph Object Gateway. The others were not active and as such they did not cause problems. With this update of Ceph the other unit files are no longer created.


Purging a containerized Ceph installation using NVMe disks no longer fails

Previously, when attempting to purge a containerized Ceph installation using NVME disks, the purge failed because of a typo in the Ansible playbook which missed identifying NVMe block devices. With this update of Red Hat Ceph Storage, the issue is fixed.


The OpenStack keys are copied to all Ceph Monitors

When Red Hat Ceph Storage was configured with run_once: true and inventory_hostname == groups.get(client_group_name) | first it can cause a bug when the only node being run is not the first node in the group. In a deployment with a single client node the keyrings will not be created since the task can be skipped. With this release this situation no longer occurs and all the OpenStack keys are copied to the monitor nodes.


The ceph-ansible utility removes the ceph-create-keys container from the same node where it was created.

Previously, the ceph-ansible utility did not always remove the ceph-create-keys container from the same node where it was created. Because of this, the deployment could fail with the message "Error response from daemon: No such container: ceph-create-keys." With this update to Red Hat Ceph Storage, ceph-ansible only tries to remove the container from the node where it was actually created, thus avoiding the error and not causing the deployment to fail.


Containers are now restarted automatically when changing their options

Previously, when changing a container option, for example, ceph_osd_docker_memory_limit, the change did not trigger a restart of the container and a manual restart was required. With this update, containers are restarted automatically when changing their options.


Updating clusters that were deployed with the mon_use_fqdn parameter set to true no longer fails

Previously, the rolling_update.yml playbook failed to update clusters that were deployed with the mon_use_fqdn parameter set to true. The playbook attempted to create or restart a systemctl service called ceph-mon@'hostname -s'.service but the service that was actually running was ceph-mon@'hostname -f'.service. This update improves the rolling_update.yml playbook, and updating such clusters now works as expected.


Upgrading Red Hat Ceph Storage 2 to version 3 will set the sortbitwise option properly

Previously, a rolling upgrade from Red Hat Ceph Storage 2 to Red Hat Ceph Storage 3 would fail because the OSDs would never initialize. This is because sortbitwise was not properly set by Ceph Ansible. With this release, Ceph Ansible sets sortbitwise properly, so the ODSs can start.


Ceph ceph-ansible now installs the gwcli command during iscsi-gw install

Previously, when using Ansible playbooks from ceph-ansible to configure an iSCSI target, the gwcli command needed to verify the installation was not available. This was because the ceph-iscsi-cli package, which provides the gwcli command, was not included as a part of the install for the Ansible playbooks. With this update to Red Hat Ceph Storage, the Ansible playbooks now install the ceph-iscsi-cli package as a part of iSCSI target configuration.


Setting the mon_use_fqdn or the mds_use_fqdn options to true fails the Ceph Ansible playbook

Starting with Red Hat Ceph Storage 3.1, Red Hat no longer supports deployments with fully qualified domain names. If either the mon_use_fqdn or mds_use_fqdn options are set to true, then the Ceph Ansible playbook will fail. If the storage cluster is already configured with fully qualified domain names, then you must set the use_fqdn_yes_i_am_sure option to true in the group_vars/all.yml file.


Containerized OSDs for which osd_auto_discovery flag was set to true properly restart during a rolling update

Previously, when using the Ansible rolling update playbook in a containerized environment, OSDs for which osd_auto_discovery flag is set to true are not restarted and the OSD services run with old image. With this release, the OSDs are restarting as expected.


Purging the cluster no longer unmounts a partition from /var/lib/ceph

Previously, if you mounted a partition to /var/lib/ceph, running the purge playbook caused a failure when it tried to unmount it.

With this update, partitions mounted to /var/lib/ceph are not unmounted during a cluster purge.


ceph-ansible now allows upgrading a cluster that is scrubbing

The ceph-ansible utility previously required all placement groups (PGs) in a cluster to be in the active+clean state. Consequently, the noscrub flag had to be set before upgrading the cluster to prevent PGs to be in the active+clean+scrubbing state. With this update, ceph-ansible allows upgrading a cluster even when the cluster is scrubbing.


Ceph installation no longer fails when trying to deploy the Object Gateway

When deploying the Ceph Object Gateway using Ansible, the rgw_hostname variable was not being set on the Object Gateway node, but was incorrectly set on the Ceph Monitor node. In this release, the rgw_hostname variable is set properly and applied to the Ceph Object Gateway node.


Installing the Object Gateway no longer fails for container deployments

When installing the Object Gateway into a container the following error was observed:

fatal: [aio1_ceph-rgw_container-fc588f0a]: FAILED! => {"changed": false,
"cmd": "ceph --cluster ceph -s -f json", "msg": "[Errno 2] No such file
or directory"

An execution task failed because there was no ceph-common package installed. This Ansible task was delegated to a Ceph Monitor node, which allows the execution to happen in the correct order.


Ansible now stops and disables the iSCSI gateway services when purging the Ceph iSCSI gateway

Previously, the ceph-ansible utility did not stop and disable the Ceph iSCSI gateway services when using the purge-iscsi-gateways.yml playbook. Consequently, the services had to be stopped manually. The playbook has been improved, and the iSCSI services are now stopped and disabled as expected when purging the iSCSI gateway.


RADOS index object creation no longer assumes rados command available on the baremetal

Previously, the creation of the rados index object in ceph-ansible assumed the rados command was available on the bare metal node, but that is not always true when deploying in containers. This can cause the task which starts NFS to fail because the rados command is missing on the host. With this update to Red Hat Ceph Storage the Ansible playbook runs rados commands from the Ceph container instead during containerized deployment.


Ansible successfully converts non-containerized Ceph deployments containing more than 99 OSDs to containers

The ceph-ansible utility failed to convert bare-metal Ceph Storage clusters that contained more than 99 OSDs to containers because of insufficient regular expressions used in the switch-from-non-containerized-to-containerized-ceph-daemons.yml playbook. The playbook has been updated, and converting non-containerized clusters to containerized works as expected.


The restarting script now tries the same amount of time for every OSD restart

The 'RETRIES' counter in the script was set at the start of the script and never reset between each call of the check_pgs() function. Consequently, the counter, which is set to 40 by default, was never reset between each restart of an OSD and was trying 40 times for all OSDs on a node. With this update, the counter is now reset between each call of the check_pgs() function, and the script tries the same amount of time for every OSD restart.


Files in /var/lib/ceph/ are now properly removed when purging clusters

The Ansible playbook for purging clusters did not properly remove files in the /var/lib/ceph/ directory. Consequently, when trying to redeploy a containerized cluster, Ansible assumed that a cluster was already running and tried to join it because the Monitor container detected some existing files in the /var/lib/ceph/<cluster-name>-<monitor-name>/ directory. With this update, the files in /var/lib/ceph/ are properly removed, and redeploying a cluster works as expected.


Ansible handles using multiple ways to set Monitor addresses as expected

Previously the ceph.conf.j2 template used an incorrect path to detect if the monitor_address_block setting was defined in the Ansible playbook. As a consequence, when using multiple ways to set a Monitor address by using the monitor_address, monitor_address_block, or monitor_interface in the inventory file, Ansible failed to generate the Ceph configuration file and returned the following error:

'ansible.vars.hostvars.HostVarsVars object' has no attribute u'ansible_interface'

With this update, the template now uses a correct path to detect the value of monitor_address_block, and Ansible handles using multiple ways to set Monitor addresses as expected.


4.2. Ceph Dashboard

The Ceph-pools Dashboard no longer displays previously deleted pools

Previously in the Red Hat Ceph Storage Dashboard, the Ceph-pools Dashboard continued to reflect pools which were deleted from the Ceph Storage Cluster. With this update to Ceph they are no longer shown after being deleted.


Installation of Red Hat Ceph Storage Dashboard with a non-default password no longer fails

Previously, the Red Hat Storage Dashboard (cephmetrics) could only be deployed with the default password. To use a different password it had to be changed in the Web UI afterwards.

With this update to Red Hat Ceph Storage you can now set the Red Hat Ceph Storage Dashboard admin username and password using Ansible variables grafana.admin_user and grafana.admin_password.

For an example of how to set these variables, see the group_vars/all.yml.sample file.


OSD ids in 'Filestore OSD latencies' are no longer repeated

Previously, after rebooting OSDs, on the Red Hat Storage Dashboard page Ceph OSD Information the OSD IDs were repeated in the section Filestore OSD Latencies.

With this update to Red Hat Ceph Storage the OSD IDs are no longer repeated on reboot of an OSD node in the Ceph OSD Information dashboard. This was fixed as a part of a redesign of the underlying data reporting.


Red Hat Ceph Storage Dashboard now reflects correct OSD count

Previously, in the Ceph Cluster dashboard in some situations the Cluster Configuration tab showed an incorrect number of OSDs. With this update, Cluster Configuration shows the correct number of OSDs.


4.3. ceph-disk Utility

The ceph-disk utility defaults to BlueStore and when replacing an OSD, passing --filestore option is required

Previously, the ceph-disk utility used BlueStore as the default object store when creating OSDs. If the --filestore option was not used, then this caused problems in storage clusters using FileStore. In this release, the ceph-disk utility now defaults to FileStore as it had originally.


4.4. CephFS

Load on MDS daemons is not always balanced fairly or evenly in multiple active MDS configurations

Previously, in certain cases, the MDS balancers offloaded too much metadata to another active daemon, or none at all.

As of this update to Red Hat Ceph Storage this is no longer an issue as several balancer fixes and optimization have been made which address the issue.


MDS no longer asserts

Previously, the Ceph Metadata Server (MDS) would sometimes assert and fail because client session imports would race with incoming client connections. With this update to Red Hat Ceph Storage, MDS handles the race condition and continues normally.


MDS no longer asserts while in starting/resolve state

Previously, when increasing "max_mds" from "1" to "2", if the Metadata Server (MDS) daemon was in the starting/resolve state for a long period of time, then restarting the MDS daemon led to an assert. This caused the Ceph File System (CephFS) to enter a degraded state. With this update to Red Hat Ceph Storage, the underlying issue has been fixed, and increasing "max_mds" no longer causes CephFS to enter a degraded state.


Client I/O sometimes fails for CephFS FUSE clients

Client I/O sometimes failed for Ceph File System (CephFS) as a File System in User Space (FUSE) client with the error transport endpoint shutdown due to an assert in the FUSE service. With this update to Red Hat Ceph Storage, the issue is resolved.


Client fails with segmentation fault and "Transport endpoint is not connected"

Previously, the the Ceph File System (CephFS) client invalidated an iterator to its capabilities while trimming its cache. This caused the client to suffer a segmentation fault. With this update to Red Hat Ceph Storage, the client prevents the iterator from being invalidating, and the client continues normally.


Monitors no longer remove MDSs from the MDS Map when processing imported capabilities for too long

The Metadata Servers (MDSs) did not reset the heartbeat packets while processing imported capabilities. Monitors interpreted this situation as MDSs being stuck and consequently removed them from the MDS Map. This behavior could cause the MDSs to flap when there were large numbers of inodes to be loaded into cache. This update provides a patch to fix this bug, and Monitors no longer remove MDSs from the MDS Map in this case.


Transient failures during dcache invalidation no longer causes ceph-fuse clients to crash

Under memory pressure, a failure during kernel dcache invalidation could cause the ceph-fuse client to terminate unexpectedly for certain kernel versions. This update adds a new mds_max_retries_on_remount_failure configuration option. This option specifies a number of consecutive retry attempts to invalidate the kernel dcache after which the ceph-fuse client would abort and it is set to 5 by default. As a result, transient failures during dcache invalidation no longer causes the ceph-fuse clients to crash.


The "is_laggy" messages no longer cause the debug log to grow to several GB per day

When the MDS detected that the connection to Monitors was laggy due to missing beacon acks, the MDS logged "is_laggy" messages to the debug log at level 1. Consequently, these messages caused the debug log to grow to several GB per day. With this update, the MDS outputs the log message once for each event of lagginess.


4.5. Ceph Manager Plugins

The fixes for pg_num/pgp_num setting through the RESTful API

Previously, attempts to change pgp_num or pg_num via the RESTful API plugin failed. With this update to Red Hat Ceph Storage, the API is able to change the pgp_num and pg_num parameter successfully.


4.6. ceph-volume Utility

The SELinux context is set correctly when using ceph-volume for new filesystems

The ceph-volume utility was not labeling newly created filesystems, which was causing AVC denial messages in the /var/log/audit/audit.log file. In this release, the ceph-volume utility sets the proper SELinux context (ceph_var_lib_t), on the OSD filesystem.


Using custom storage cluster name is now supported

When using a custom storage cluster name other than ceph, the OSDs could not start after a reboot. With this update, using custom cluster names is supported, and rebooting OSDs works as expected in this case.


4.7. Containers

The containerized Object Gateway daemon will read options from the Ceph configuration file now

When launching the Object Gateway daemon in a container, the daemon would override any rgw_frontends options. This made it impossible to add extra options, such as, the radosgw_civetweb_num_threads option. In this release, the Object Gateway daemon will read options found in the Ceph configuration file, by default, /etc/ceph/ceph.conf.


A dmcrypt OSD comes up after upgrading a containerized Red Hat Ceph Storage cluster to 3.x

Previously, on FileStore, ceph-disk created the lockbox partition for dmcrypt on partition number 3. With the introduction of BlueStore, this partition is now on position number 5, but ceph-disk was trying to create the partition on position number 3 causing the OSD to fail. In this release, ceph-disk can now detect the correct partition to use for the lockbox partition.


4.8. iSCSI Gateway

LUN resize on target side Ceph is now reflected on clients

Previously, when using the iSCSI gateway, resized Logical Unit Numbers (LUNs) were not immediately visible to initiators. This required a work around of restarting the iSCSI gateway after resizing a LUN to expose it to the initiators.

With this update to Red Hat Ceph Storage, iSCSI initiators can now see a resized LUN immediately after rescan.


The iSCSI gateway supports custom cluster names

Previously, the Ceph iSCSI gateway only worked with the default storage cluster name (ceph). In this release, the rbd-target-gw now supports arbitrary Ceph configuration file locations, which allows the use of storage clusters not named ceph.

The Ceph iSCSI gateway can be deployed using Ceph Ansible or using the command-line interface with a custom cluster name.


Pools and images with hyphens ('-') are no longer rejected by the API

Previously, the iSCSI gwcli utility did not support hyphens in pool or image names. As such it was not possible to create a disk using a pool or image name that included hyphens ("-") by using the iSCSI gwcli utility.

With this update to Red Hat Ceph Storage, the iSCSI gwcli utility correctly handles hyphens. As such creating a disk using a pool or image name with hyphens is now supported.


The DM-Multipath device’s path no longer bounces between the failed and active state causing I/O failures, hangs, and performance issues

In Red Hat Enterprise Linux 7.5, the kernel’s ALUA layer reduced the number of times an initiator retries the SCSI sense code ALUA State Transition. This code is returned from the target side by the tcmu-runner service when taking the RBD exclusive lock during a failover or failback scenario and during a device discovery. As a consequence, the maximum number of retries had occurred before the discovery process was completed, and the SCSI layer returned a failure to the multipath I/O layer. The multipath I/O layer tried the next available path, and the same problem occurred. This behavior caused a loop of path checking, resulting in failed I/O operations and management operations to the multipath device. In addition, the logs on the initiator node printed messages about devices being removed and then re-added. This bug has been fixed, and the aforementioned operations no longer fail.


Discovering iSCSI paths during the boot, setup, or scanning process no longer causes the DM-Multipath feature to fail to set up

During device and path setup, the initiator sent commands to all paths at the same time. This behavior caused the Ceph iSCSI gateways to take the RBD lock from one device and set it on another device. In some cases, the iSCSI gateway interpreted the lock being taken away in this manner as a hard error and escalated its error handler by dropping the iSCSI connection, reopening the RBD devices to clear old states, and then enabling the iSCSI target port group to allow a new iSCSI connection. This caused a disruption to the device and path discovery when disabling and enabling the iSCSI target port group. In turn, the multipath I/O layer continually was disabling and enabling all paths and I/O was suspended, or device and path discovery could fail and the device was not setup. This bug has been fixed, and rebooting an iSCSI initiator with connected devices no longer leads to this error.


4.9. Object Gateway

Quota stats cache is no longer invalid

Previously in Red Hat Ceph Storage, quota values sometimes were not properly decremented. This could cause exceed errors when the quota was not actually exceeded.

With this update to Ceph, quota values are properly decremented and no incorrect errors are printed.


Object compression works properly

Previously, when using zlib compression with Object Gateway, objects were not being compressed properly. The actual size and used size were listed as the same despite log messages saying compression was in use. This was due to the usage of smaller buffers. With this update to Red Hat Ceph Storage, larger buffers are used and compression works as expected.


Marker objects no longer appear twice when listing objects

Previously, due to an error in processing, "marker" objects that were used to continue multi-segment listings were included incorrectly in the listing result. Consequently, such objects appeared twice in the listing output. With this update to Red Hat Ceph Storage, objects are only listed once, as expected.


Resharding a bucket that has ACLs set no longer alters the bucket ACL

Previously, in the Ceph Object Gateway (RGW), resharding a bucket with an access control list (ACL) set alters the bucket ACL. With this update to Red Hat Ceph Storage, ACLs on a bucket are preserved even if they are resharded.


Intermittent HTTP error code 409 no longer occurs with compression enabled

Previously, HTTP error codes could be encountered due to EEXIST being incorrectly handled in RGWPutObj::execute() in a special case. This caused the PUT operation to be incorrectly failed to the client, when it should have been retried. In this update to Red Hat Ceph Storage, the EEXIST condition handling has been corrected and this issue no longer occurs.


RGW no longer spikes to 100% CPU usage with no op traffic

Previously in certain situations an infinite loop could be encountered in rgw_get_system_obj(). This could cause spikes in CPU usage. With this update to Red Hat Ceph Storage this specific issue has been resolved.


The implicit tenant feature has been enhanced

The Ceph Object Gateway implicit tenants feature can increase data isolation between users, but it could require moving data to make it non-shared. Additionally, early versions of implicit tenants behaved differently, which created migration and provisioning challenges; for example, Simple Storage Service (S3) users saw common bucket namespace while Swift users saw separate per-tenant namespaces. As a consequence, when using implicit tenants, users could not see old data, or could not share them. Also, when migrating from earlier versions, old S3 users continued to see the shared namespace, but new S3 users saw separated namespaces. With this update, implicit tenants has been enhanced to provide a more predictable version of the previous behavior. In addition, the radosgw-admin bucket link command has been updated to provide a new bucket move function. This function allows buckets to be moved between tenants, or to and from the non-tenanted "global" namespace. As a result, with proper use of these features, users can continue to access their old data.

(BZ#1564520, BZ#1595379)

Cache entries now refresh as expected

The new time-based metadata cache entry expiration logic did not include logic to update the expiration time on already-cached entries being updated in place. Cache entries became permanently stale after expiration, leading to a performance regression as metadata objects were effectively not cached and always read from the cluster. To resolve this issue, in Red Hat Ceph Storage 3.1, logic has been added to update the expiration time of cached entries when updated.


Ceph is now able to delete/remove swift ACLs

Previously, the Swift CLI client could be used to set, but not to delete ACLs because the Swift header parsing logic could not detect ACL delete requests. With this update to Red Hat Ceph Storage, the header parsing logic has been fixed, and users can delete ACLs with the Swift client.


Buckets can be deleted as expected

Previously, when the bucket index contained missing incomplete multipart upload operations, the bucket could not be deleted. With this update, the missing multipart upload operations are ignored and buckets can be deleted successfully.


Quotas are now applied to shadow users

Previously, Ceph Object Gateway quotas were not applied to shadow users such as those created by using the Red Hat OpenStack Keystone service or LDAP with Red Hat Ceph Storage. This bug has been fixed, and the quotas are now applied as expected.


4.10. Object Gateway Multisite

Some versioned objects do not sync when uploaded with 's3cmd sync'

Operations like PutACL that only modify object metadata do not generate a LINK_OLH entry in the bucket index log. When processed by multisite sync, these operations were skipped with the message versioned object will be synced on link_olh. Because of sync squashing, this caused the original LINK_OLH operation to be skipped as well, preventing the object version from syncing at all. With this update to Red Hat Ceph Storage this issue no longer occurs.


RGW multisite does not sync all objects

Previously, in the Ceph Object Gateway multisite scenarios, an HTTP request to another gateway would not complete. Therefore, multisite sync would wait forever on the request and could not make further progress. With this update to Red Hat Ceph Storage, a timeout to the "libcurl" request has been added, and HTTP requests that do not complete will time out and be retried, allowing multisite sync to continue.


Redundant multi-site replication sync errors were moved to debug level 10

A few multi-site replication sync errors were logged multiple times at log level 0 and consumed extra space in logs. This update moves the redundant messages to debug level 10 to hide them from the log.


4.11. RADOS

The Ceph OSD daemon terminates with a segmentation fault

Previously, a subtle race condition in the ceph-osd daemon could lead to the corruption of the osd_health_metrics data structure which results in corrupted data being sent to, and reported by, the Ceph Manager. This ultimately caused a segmentation fault. With this update to Red Hat Ceph Storage, a lock is now acquired before modifying the osd_health_metrics data structure.


The default limit on PGs per OSD has been increased

In some situations, such as widely varying disk sizes, the default limit on placement groups (PGs) per OSD could prevent PGs from becoming active. These limits have been increased by default to make this scenario less likely.


PGs stuck activating now appear in the OSD log at the default log level

Placement groups (PGs) that are stuck activating due to hard limits on PGs per OSD now appear in the OSD log at the default log level, so this situation is easier to diagnose.


Reduced OSD memory usage

Buffers from client operations were not being rebuilt, which was leading to unnecessary memory growth by an OSD process. Rebuilding the buffers has reduced the memory footprint for OSDs in Object Gateway workloads.


PG log length is now limited

Previously, the osd_max_pg_log_entries option did not set a hard limit for the placement group (PG) log length. Consequently, during recovery and backfill, the log could grow significantly and consume a lot of memory, in some cases even all of it. With this update, a hard limit is set on the number of log entries in the PG log even during recovery and backfill.

A corner case, where it might be hard to limit the PG log length, is on erasure-coded pools, when the rollback information on some of replicas is too old for some reason.


Fixed verbosity for a log message

Ceph message passing stack had a message with low verbosity set unnecessarily. Consequently, debug log at low verbosity filled with inconsequential message. This update fixes the verbosity, and low debug logs no longer include the message.


Rollback data for erasure-coded pools is only removed when it is safe

In certain circumstances, erasure-coded pools attempted to use internal rollback data that they had removed before. Consequently, OSD daemons terminated unexpectedly. With this update, rollback data for erasure-coded pools is only removed when it is safe, and OSDs no longer crash in the described scenario.


4.12. Block Devices (RBD)

Live migration of VMs using RBD images no longer times out when restarting OSD daemons

Restarting OSD daemons, for example for rolling updates, could result in an inconsistent internal state within librbd clients with the exclusive lock feature enabled. As a consequence, live migration of virtual machines (VMs) using RBD images could time out because the source VM would refuse to release its exclusive lock on the RBD image. This bug has been fixed, and the live migration proceeds as expected.


4.13. RBD Mirroring

RBD images can now be removed even if the optional journal is missing or corrupt

If the RBD journaling feature is enabled, a missing journal prevents the image from being opened in an attempt to prevent possible data corruption. This safety feature also prevented an image from being removed if its journal was unavailable. Previously, the journaling feature had to be disabled before attempting to remove the image if this situation occurred. With this update, RBD image removal skips any attempt to open the journal because its integrity is not important when the image is being deleted. As a result, RBD images can now be removed even if the optional journal is missing or corrupt.


Chapter 5. Technology previews

This section provides an overview of Technology Preview features introduced or updated in this release of Red Hat Ceph Storage.


Technology Preview features are not supported with Red Hat production service level agreements (SLAs), might not be functionally complete, and Red Hat does not recommend to use them for production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information on Red Hat Technology Preview features support scope, see

OSD BlueStore

BlueStore is a new back end for the OSD daemons that allows for storing objects directly on the block devices. Because BlueStore does not need any file system interface, it improves performance of Ceph Storage Clusters.

To learn more about the BlueStore OSD back end, see the OSD BlueStore (Technology Preview) chapter in the Administration Guide.

Support for RBD mirroring to multiple secondary clusters

Mirroring RADOS Block Devices (RBD) from one primary cluster to multiple secondary clusters is now supported as a technology preview.

Erasure Coding for Ceph Block Devices

Erasure coding for Ceph Block Devices is now supported as a Technology Preview. For details, see the Erasure Coding with Overwrites (Technology Preview) section in the Storage Strategies Guide for Red Hat Ceph Storage 3.

Chapter 6. Known issues

This section documents known issues found in this release of Red Hat Ceph Storage.

6.1. Ceph Ansible

The shrink-osd.yml playbook currently has no support for removing OSDs created by ceph-volume

The shrink-osd.yml playbook assumes all OSDs are created by the ceph-disk utility. Consequently, OSDs deployed by using the ceph-volume utility cannot be shrunk.

To work around this issue, remove OSDs deployed by using ceph-volume manually.


When putting a dedicated journal on an NVMe device installation can fail

When the dedicated_devices setting contains an NVMe device and it has partitions or signatures on it Ansible installation might fail with an error like the following:

journal check: ondisk fsid 00000000-0000-0000-0000-000000000000 doesn't match expected c325f439-6849-47ef-ac43-439d9909d391, invalid (someone else's?) journal

To work around this issue ensure there are no partitions or signatures on the NVMe device.


When the mon_use_fqdn option is set to true the rolling upgrade fails

For Red Hat Ceph Storage 2 container deployments using the mon_use_fqdn = true option, upgrading to Red Hat Ceph Storage 3.1z1 using the Ceph Ansible rolling upgrade playbook fails. Currently, there are no known workarounds.


6.2. Ceph Dashboard

The 'iSCSI Overview' page does not display correctly

When using the Red Hat Ceph Storage Dashboard, the 'iSCSI Overview' page does not display any graphs or values as it is expected to.


Ceph OSD encryption summary is not displayed in the Red Hat Ceph Storage Dashboard

On the Ceph OSD Information dashboard, under the OSD Summary panel, the OSD Encryption Summary information is not displayed. Currently, there is no workaround for this issue.


The Prometheus node-exporter service is not removed after purging the Dashboard

When doing a purge of the Red Hat Ceph Storage Dashboard, the node-exporter service is not removed, and is still running. To work around this issue, you manually stop and remove the node-exporter service.

Perform the following commands as root:

# systemctl stop prometheus-node-exporter
# systemctl disable prometheus-node-exporter
# rpm -e prometheus-node-exporter
# reboot

For Ceph Monitor, OSD, Object Gateway, MDS, and Dashboard nodes, reboot these ones at a time.


The OSD node details are not displayed in the Host OSD Breakdown panel

In the Red Hat Ceph Storage Dashboard, the Host OSD Breakdown information is not displayed on the OSD Node Detail panel under All.


6.3. iSCSI Gateway

Using ceph-ansible to deploy the iSCSI gateway does not allow the user to adjust the max_data_area_mb option

Using the max_data_area_mb option with the ceph-ansible utility sets a default value of 8 MB. To adjust this value, you set it manually using the gwcli command. See the Red Hat Ceph Storage Block Device Guide for details on setting the max_data_area_mb option.


6.4. Object Gateway

The Ceph Object Gateway requires applications to write sequentially

The Ceph Object Gateway requires applications to write sequentially from offset 0 to the end of a file. Attempting to write out of order causes the upload operation to fail. To work around this issue, use utilities like cp, cat, or rsync when copying files into NFS space. Always mount with the sync option.


RGW garbage collection fails to keep pace during evenly balanced delete-write workloads

In testing during an evenly balanced delete-write (50% / 50%) workload the cluster fills completely in eleven hours. Object Gateway garbage collection fails to keep pace. This causes the cluster to fill completely and the status switches to HEALTH_ERR state. Aggressive settings for the new parallel/async garbage collection tunables did significantly delay the onset of cluster fill in testing, and can be helpful for many workloads. Typical real world cluster workloads are not likely to cause a cluster fill due primarily to garbage collection.


RGW garbage collection decreases client performance by up to 50% during mixed workload

In testing during a mixed workload of 60% reads, 16% writes, 14% deletes, and 10% lists, at 18 hours into the testing run, client throughput and bandwidth drop to half their earlier levels.


6.5. RADOS

High object counts can degrade IO performance

The overhead with directory merging on FileStore can degrade the client’s IO performance for pools with high object counts.

To work around this issue, use the ‘expected_num_objects’ option during pool creation. Creating pools is described in the Red Hat Ceph Storage Object Gateway for Production Guide.


When two or more Ceph Gateway daemons have the same name in a cluster Ceph Manager can crash

Currently, Ceph Manager can terminate unexpectedly if some Ceph Gateway daemons have the same name. The following assert is be generated in this case:


To work around this issue, rename all the Ceph Gateway daemons that have the same name with new unique names.


Chapter 7. Sources

The updated Red Hat Ceph Storage source code packages are available at the following locations:

Legal Notice

Copyright © 2018 Red Hat, Inc.
The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version.
Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law.
Red Hat, Red Hat Enterprise Linux, the Shadowman logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries.
Linux® is the registered trademark of Linus Torvalds in the United States and other countries.
Java® is a registered trademark of Oracle and/or its affiliates.
XFS® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries.
MySQL® is a registered trademark of MySQL AB in the United States, the European Union and other countries.
Node.js® is an official trademark of Joyent. Red Hat Software Collections is not formally related to or endorsed by the official Joyent Node.js open source or commercial project.
The OpenStack® Word Mark and OpenStack logo are either registered trademarks/service marks or trademarks/service marks of the OpenStack Foundation, in the United States and other countries and are used with the OpenStack Foundation's permission. We are not affiliated with, endorsed or sponsored by the OpenStack Foundation, or the OpenStack community.
All other trademarks are the property of their respective owners.
Red Hat logoGithubRedditYoutubeTwitter


Try, buy, & sell


About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

© 2024 Red Hat, Inc.