[Lustre-discuss] Backing up Lustre Journal

[Dilger, Andreas]

On 2014/06/19, 6:55 PM, "Alastair Ferguson" <aferguson at cmcrc.com<mailto:aferguson at cmcrc.com>> wrote:

OK, so I have a RAID1 array used as Journal disk for two 14TB OSTs. this has 2 x 2GB partitions on 2 x 2TB physical disks.

[root at silicon ~]# fdisk -l /dev/sdav

Disk /dev/sdav: 2000.3 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

    Device Boot      Start         End      Blocks   Id  System
/dev/sdav1               1          56      449788+  fd  Linux raid autodetect
/dev/sdav2              57         112      449820   fd  Linux raid autodetect

One of the RAID1 disks is about to fail and before I replace it I would like to back up the journals so I can recover.

There doesn’t seem to be any information on how to do this.

Can I mount -t ldiskfs and then rsync the information somewhere just in case the RAID1 replacement doesn’t work?

What is the procedure for this?

There is nothing to back up on the journal disk.  This is only needed in case of a crash and to avoid e2fsck on recovery.  If you make a backup of the filesystem that is enough.


Cheers, Andreas
--
Andreas Dilger
Lustre Software Architect
Intel High Performance Data Division