[lustre-discuss] [EXTERNAL] migrating mgs and mdt

[Mohr, Rick]

Lana,

It has probably been 10 years since I have done it, but at one point I did successfully use dd to transfer a mdt/mgt from one device to another.  This was for an ldiskfs-formatted partition.  I you are using zfs on the backend, you could also just use the zfs send/receive functionality for zfs snapshots to move the data to another device.

--Rick


On 12/9/24, 3:13 PM, "lustre-discuss on behalf of Lana Deere" <lustre-discuss-bounces at lists.lustre.org <mailto:lustre-discuss-bounces at lists.lustre.org> on behalf of lana.deere at gmail.com <mailto:lana.deere at gmail.com>> wrote:


I am managing a Lustre 2.12.6 system where I have just discovered that the MGS and MDTs are on single disks rather than RAIDed drives.


/dev/sda5 on /mnt/lustre_mgs type lustre (ro,svname=MGS,nosvc,mgs,osd=osd-ldiskfs,...)
/dev/sdc1 on /mnt/lustre_mdt_abc type lustre (ro,svname=lstr_abc-MDT0000,mgsnode=10.58.255.254 at o2ib,osd=osd-ldiskfs,...)
/dev/sdb1 on /mnt/lustre_mdt_def type lustre (ro,svname=lstr_def-MDT0000,mgsnode=10.58.255.254 at o2ib,osd=osd-ldiskfs,...)




Is there any way to migrate those three metadata partitions to other partitions which would presumably be located on RAIDed drives? For example, would it work to set up the new RAIDed drives and use dd to clone the partitions into partitions on the RAID?


.. Lana (lana.deere at gmail.com <mailto:lana.deere at gmail.com> <mailto:lana.deere at gmail.com <mailto:lana.deere at gmail.com>>)