Lustre 1.6 Operations Manual

4.2.1.3 Filesystem Name
The filesystem name is limited to 8 characters. We have encoded the filesystem and
target information in the disk label, so that you can mount by label. This allows
system administrators to move disks around without worrying about issues such as
SCSI disk reordering or getting the /dev/device wrong for a shared target. Soon,
filesystem naming will be made as fail-safe as possible. Currently, Linux disk labels
are limited to 16 characters. To identify the target within the filesystem, 8 characters
are reserved, leaving 8 characters for the filesystem name:
myfsname-MDT0000 or myfsname-OST0a19
An example of mount-by-label:
$ mount -t lustre -L testfs-MDT0000 /mnt/mdt
Caution – Mount-by-label should NOT be used in a multi-path environment.
Although the filesystem name is internally limited to 8 characters, you can mount
the clients at any mount point, so filesystem users are not subjected to short names:
mount -t lustre uml1@tcp0:/shortfs /mnt/my-long-filesystem-name
4.2.1.4 Starting a Server Automatically
Starting Lustre only involves the mount command. Lustre servers can be added to
/etc/fstab:
$ mount -l -t lustre
/dev/sda1 on /mnt/test/mdt type lustre (rw) [testfs-MDT0000]
/dev/sda2 on /mnt/test/ost0 type lustre (rw) [testfs-OST0000]
192.168.0.21@tcp:/testfs on /mnt/testfs type lustre (rw)
Add to /etc/fstab:
LABEL=testfs-MDT0000 /mnt/test/mdt lustre defaults,_netdev,noauto 0 0
LABEL=testfs-OST0000 /mnt/test/ost0 lustre defaults,_netdev,noauto 0 0
In general, it is wise to specify noauto and let your high-availability (HA) package
manage when to mount the device. If you are not using failover, make sure that
networking has been started before mounting a Lustre server. RedHat, SuSe, Debian
(maybe others) use the _netdev flag to ensure that these disks are mounted after
the network is up.
4-8 Lustre 1.6 Operations Manual • September 2008