Hi.
Is it possible to fsck on a disabled and drained OST that is mounted readonly?
We need to fsck an OST and would like to avoid a lengthy downtime while doing
it. My plan is to disable and drain the files from the OST and then remount it
read-only before running fsck on the partition. This would allow for the
system being online during this operation instead of hanging on all df
commands etc. But is it at all possible to do it this way? I would like to
avoid any large scale catastrophic events...
Regards,
r.
--
The Computer Center, University of Troms?, N-9037 TROMS? Norway.
phone:+47 77 64 41 07, fax:+47 77 64 41 00
Roy Dragseth, Team Leader, High Performance Computing
Direct call: +47 77 64 62 56. email: roy.dragseth at uit.no
Hello! On Mar 18, 2010, at 1:36 PM, Roy Dragseth wrote:> Is it possible to fsck on a disabled and drained OST that is mounted readonly? > We need to fsck an OST and would like to avoid a lengthy downtime while doing > it. My plan is to disable and drain the files from the OST and then remount it > read-only before running fsck on the partition. This would allow for the > system being online during this operation instead of hanging on all df > commands etc. But is it at all possible to do it this way? I would like to > avoid any large scale catastrophic events...You can just disable a specific ost with a command like lctl conf_param ${fs_name}-OST${NUM}.osc.activate=0 That''d propagate to all clients and even if you bring that ost down later on, client''s won''t hang but rather would return an i/o error trying to read/write data from that OST. df would just stop counting usage (both free and used) from that ost. After you are done, execute same command, but make it =1 to reenable the OST everywhere. Bye, Oleg
On 2010-03-18, at 11:36, Roy Dragseth wrote:> Is it possible to fsck on a disabled and drained OST that is mounted > readonly? > > We need to fsck an OST and would like to avoid a lengthy downtime > while doing > it. My plan is to disable and drain the files from the OST and then > remount it read-only before running fsck on the partition. This > would allow for the > system being online during this operation instead of hanging on all df > commands etc. But is it at all possible to do it this way? I would > like to > avoid any large scale catastrophic events...If the filesystem is damaged and you need to run e2fsck on it, then modifying the filesystem by trying to drain the files from the OST is a bad idea. You should minimize the amount of changes made to the filesystem before you can run e2fsck on it. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc.