Release Notes
Release notes for Red Hat Ceph Storage 3.1
Abstract
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 https://access.redhat.com/documentation/en/red-hat-ceph-storage/.
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.
(BZ#1547999)
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.
(BZ#1597516)
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 restart_osd_daemon.sh
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.
(BZ#1572722)
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.
(BZ#1578140)
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.
(BZ#1585031)
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.
(BZ#1614780)
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.
(BZ#1628055)
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.
(BZ#1630870)
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.
(BZ#1589545)
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.
(BZ#1580300)
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 https://access.redhat.com/support/offerings/techpreview/.
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.
(BZ#1646882)
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:
DaemonPerfCounters::update(MMgrReport*)
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:
- For Red Hat Enterprise Linux: http://ftp.redhat.com/redhat/linux/enterprise/7Server/en/RHCEPH/SRPMS/
- For Ubuntu: https://rhcs.download.redhat.com/ubuntu/