3.5. Storage and File Systems

The hpsa driver installed from the AMD64 and Intel 64 Driver Update Program ISO might not be loaded properly on Red Hat Enterprise Linux 6.3. Consequently, the system can become unresponsive. To work around this problem, use the pci=nomsi kernel parameter before installing the driver from the ISO.

When issue_discards=1 is configured in the /etc/lvm/lvm.conf file, moving physical volumes via the pvmove command results in data loss. To work around this issue, ensure that issue_discards=0 is set in your lvm.conf file before moving any physical volumes.

When using the lvmetad daemon (currently a Technology Preview), avoid passing the --test argument to commands. The use of the --test argument may lead to inconsistencies in the cache that lvmetad maintains. This issue will be fixed in a future release. If the --test argument has been used, fix any problems by restarting the lvmetad daemon.

It is not possible to rename thin logical volumes using tools provided in the current LVM2 release. The rename operation returns the following error:

lvrename Cannot rename <volume_name>: name format not recognized for internal LV <pool_name>

This issue will be fixed in the next LVM2 release.

Multipath's queue_without_daemon yes default option queues I/O even though all iSCSI links have been disconnected when the system is shut down, which causes LVM to become unresponsive when scanning all block devices. As a result, the system cannot be shut down. To work around this issue, add the following line into the defaults section of /etc/multipath.conf:

queue_without_daemon no

Running the file system check (using fsck) on a NFS mounted file system fails, and causes the system to fail to boot and drop into a shell. To work around this issue, disable fsck on any /boot partitions by setting the sixth value of a /boot entry in /etc/fstab to 0.

The NFSv4 server in Red Hat Enterprise Linux 6 currently allows clients to mount using UDP and advertises NFSv4 over UDP with rpcbind. However, this configuration is not supported by Red Hat and violates the RFC 3530 standard.

The dracut utility currently only supports one FiberChannel over Ethernet (FCoE) connection to be used to boot from the root device. Consequently, booting from a root device that spans multiple FCoE devices (for example, using RAID, LVM or similar techniques) is not possible.

The pvmove command cannot currently be used to move mirror devices. However, it is possible to move mirror devices by issuing a sequence of two commands. For mirror images, add a new image on the destination PV and then remove the mirror image on the source PV:

~]$ lvconvert -m +1 <vg/lv> <new PV>
~]$ lvconvert -m -1 <vg/lv> <old PV>

Mirror logs can be handled in a similar fashion:

~]$ lvconvert --mirrorlog core <vg/lv>
~]$ lvconvert --mirrorlog disk <vg/lv> <new PV>

or

~]$ lvconvert --mirrorlog mirrored <vg/lv> <new PV>
~]$ lvconvert --mirrorlog disk <vg/lv> <old PV>