Developers Guide

Volume management
14 Dell EMC SC Series with Red Hat Enterprise Linux 7x | CML1071
Note: The attempt to mount /dev/mapper/vol_004 as /vol_004 fails because the UUID is not unique and
already in use on the Linux host.
# df -k
Filesystem 1K-blocks Used Available Use% Mounted on
[snip]
rhevm:/nfsroot 103213056 54833152 43137024 56% /Tools
/dev/mapper/vol_001 52418560 1939052 50479508 4% /vol_001
[snip]
Attempting to mount /dev/mapper/vol_004 to /vol_004 returns the following error.
# mount –o discard,sync /dev/mapper/vol_004 /vol_004
mount: wrong fs type, bad option, bad superblock on /dev/mapper/vol_004,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so.
Attempting to mount /dev/mapper/vol_004 to /vol_004 along with the nouuid parameter allows the volume
to be successfully mounted to /vol_004.
# mount –o discard,sync,nouuid /dev/mapper/vol_004 /vol_004; df –k
# df -k
Filesystem 1K-blocks Used Available Use% Mounted on
[snip]
rhevm:/nfsroot 103213056 54833152 43137024 56% /Tools
/dev/mapper/vol_001 52418560 1939052 50479508 4% /vol_001
/dev/mapper/vol_004 52418560 1939052 50479508 4% /vol_004
[snip]
Alternatively, the UUID value associated with /dev/mapper/vol_004 can be changed permanently to remove
the need for specifying the nouuid parameter with the mount command. This can be performed (applied to an
unmounted filesystem) as shown in the following.
# xfs_admin -U generate /dev/mapper/vol_004
Clearing log and setting UUID
writing all SBs
new UUID = 26b4a32d-4a3a-405f-899c-7bb63087cc7b
2.7 Expanding XFS filesystem enabled volumes
With RHEL 7.x, volume and filesystem expansion in Linux is simple and effective. After the underlying
SC Series volume has been increased in size, the filesystem residing on top of the volume can be resized to
the full limit of the underlying volume or resized to a predetermined size as specified by the system
administrator. The process for volume and XFS filesystem expansion is outlined in the following steps.