LVM does not support event-based autoactivation of incomplete volume groups
If a volume group is not complete and physical volumes are missing, LVM does not support automatic LVM event-based activation of that volume group. This implies a setting of
--activationmode complete whenever autoactivation takes place. For information on the
--activationmode complete option and automatic activation, see the
pvscan(8) man pages.
Note that the event-driven autoactivation hooks are enabled when
lvmetad is enabled with the
global/use_lvmetad=1 setting in the
/etc/lvm/lvm.conf configuration file. Also note that without autoactivation, there is a direct activation hook at the exact time during boot at which the volume groups are activated with only the physical volumes that are available at that time. Any physical volumes that appear later are not taken into account.
This issue does not affect early boot in
) nor does this affect direct activation from the command line using
calls, which default to
activation mode. (BZ#1337220
vdo service is disabled after upgrading to Red Hat Enterprise Linux 7.6
Upgrading from Red Hat Enterprise Linux 7.5 to 7.6 disables the
vdo service if it was previously enabled. This is because of missing
systemd macros in the vdo RPM package.
The problem has been fixed in the 7.6 release, and upgrading from Red Hat Enterprise Linux 7.6 to a later release will no longer disable
Data corruption occurs on RAID 10 reshape on top of VDO.
RAID 10 reshape (with both LVM and
) on top of VDO corrupts data. Stacking RAID 10 (or other RAID types) on top of VDO does not take advantage of the deduplication and compression capabilities of VDO and is not recommended. (BZ#1528466
System boot is sometimes delayed by ndctl
udev rule installed by the ndctl package sometimes delays the system boot process for several minutes on systems with Non-Volatile Dual In-line Memory Module (NVDIMM) devices. In such cases,
systemd displays a message similar to the following:
INFO: task systemd-udevd:1554 blocked for more than 120 seconds.
To work around the issue, disable the
udev rule using the following command:
# rm /usr/lib/udev/rules.d/80-ndctl.rules
After disabling the
udev rule, the described problem no longer occurs. (BZ#1635441)
LVM might cause data corruption in the first 128kB of allocatable space of a physical volume
A bug in the I/O layer of LVM causes LVM to read and write back the first 128kB of data that immediately follows the LVM metadata on the disk. If another program or the file system is modifying these blocks when you use an LVM command, changes might be lost. As a consequence, this might lead to data corruption in rare cases.
To work around this problem, avoid using LVM commands that change volume group (VG) metadata, such as
, while logical volumes (LVs) in the VG are in use. (BZ#1643651