Hello, I installed lustre on three machines (mc0, mc1, mc2) I configured lustre, on mc0 as MDT & MGS pair AND OST1, on mc1 as OST2 on mc2 as client I want OST2 to be a mirror of OST1. That is, if I copy a file to OST1, it will also be copied to OST2. OST2 should be a backup for OST1. Can I do this configuration using default lustre options ? Can it be accomplished by --failnode directive ? If so, how can I do it Thanks in advance -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.lustre.org/pipermail/lustre-discuss/attachments/20090710/6989c8f1/attachment-0001.html
On Jul 10, 2009 15:34 +0300, Onane wrote:> I installed lustre on three machines (mc0, mc1, mc2) > > I configured lustre, > on mc0 as MDT & MGS pair AND OST1, > on mc1 as OST2 > on mc2 as client > > I want OST2 to be a mirror of OST1. That is, if I copy a file to OST1, it > will also be copied to OST2. OST2 should be a backup for OST1. > > Can I do this configuration using default lustre options ? Can it be > accomplished by --failnode directive ? If so, how can I do itNo, this isn''t yet supported by Lustre. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc.
Okey. Is there any other way for doing it ? In my configuration, OST1 has 80GB & OST2 has 80GB. If I gave them same fsname & mgsnode, I would access 160GB lustre filesystem on client. I want to use these two volumes like raid 1. That is, how can I configure lustre filesystem so that OST2 back up OST1 (say. every hour) ? On Fri, Jul 10, 2009 at 8:07 PM, Andreas Dilger <adilger at sun.com> wrote:> On Jul 10, 2009 15:34 +0300, Onane wrote: > > I installed lustre on three machines (mc0, mc1, mc2) > > > > I configured lustre, > > on mc0 as MDT & MGS pair AND OST1, > > on mc1 as OST2 > > on mc2 as client > > > > I want OST2 to be a mirror of OST1. That is, if I copy a file to OST1, it > > will also be copied to OST2. OST2 should be a backup for OST1. > > > > Can I do this configuration using default lustre options ? Can it be > > accomplished by --failnode directive ? If so, how can I do it > > No, this isn''t yet supported by Lustre. > > Cheers, Andreas > -- > Andreas Dilger > Sr. Staff Engineer, Lustre Group > Sun Microsystems of Canada, Inc. > >-------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.lustre.org/pipermail/lustre-discuss/attachments/20090713/5a1862ca/attachment.html
On Mon, 2009-07-13 at 12:07 +0300, Onane wrote:> Okey. Is there any other way for doing it ?No.> In my configuration, OST1 has 80GB & OST2 has 80GB. If I gave them > same fsname & mgsnode, I would access 160GB lustre filesystem on > client. I want to use these two volumes like raid 1. That is, how can > I configure lustre filesystem so that OST2 back up OST1 (say. every > hour) ?As Andreas has already said, Lustre cannot do this for you. Perhaps you want to look into having your two OSSes (mc0 and mc1), serving up the (virtually) same OST, mirrored with DRBD or the like. There has been a fair amount of discussion on this list on that. Please search the archives. Please also note, that we (Sun) have not verified definitively one way or the other if DRBD has the right semantics to provide a true mirror of the OST such that Lustre will not have a problem with a failover involving it, so it''s up to you to verify for yourself whether it''s a suitable solution or not. Cheers, b. -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 197 bytes Desc: This is a digitally signed message part Url : http://lists.lustre.org/pipermail/lustre-discuss/attachments/20090713/99697ae6/attachment.bin
On Jul 13, 2009 12:07 +0300, Onane wrote:> In my configuration, OST1 has 80GB & OST2 has 80GB. If I gave them same > fsname & mgsnode, I would access 160GB lustre filesystem on client. I want > to use these two volumes like raid 1. That is, how can I configure lustre > filesystem so that OST2 back up OST1 (say. every hour) ?One possible way to do this, as Brian suggested, is to use DRBD and do the mirroring below the level that Lustre sees, at the block device level. Another possibility is to create a top-level directory in the filesystem with "lfs setstripe -c 1 -i 0 /mnt/lustre/primary" and create all of the files in that directory (it will inherit the striping that forces files to be created on OST index 0), and then rsync all of the files to a separate directory with "lfs setstripe -c 1 -i 1 /mnt/lustre/backup". That would work on 1.6.x for 2 OSTs, but the file creation is not strictly contained to the OSTs that are specified by default striping. In 1.8.x it would be more flexible to create an OST pool that contains one or more "primary" OSTs, and then a second OST pool that contains one or more "backup" OSTs. The file creation will be strictly enforced to be within the respective pools. It isn''t an ideal solution, and I _wish_ we had RAID-1 at the OST level, but that still hasn''t made it to the top of the "we need this for Lustre" feature list.> On Fri, Jul 10, 2009 at 8:07 PM, Andreas Dilger <adilger at sun.com> wrote: > > On Jul 10, 2009 15:34 +0300, Onane wrote: > > > I installed lustre on three machines (mc0, mc1, mc2) > > > > > > I configured lustre, > > > on mc0 as MDT & MGS pair AND OST1, > > > on mc1 as OST2 > > > on mc2 as client > > > > > > I want OST2 to be a mirror of OST1. That is, if I copy a file to OST1, it > > > will also be copied to OST2. OST2 should be a backup for OST1. > > > > > > Can I do this configuration using default lustre options ? Can it be > > > accomplished by --failnode directive ? If so, how can I do it > > > > No, this isn''t yet supported by Lustre.Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc.