Hi all, I want to move a MDT from one server to another. After studying some mails concerning MDT backup, I've just tried (successfully, it seems) to do that on a small test system with rsync:
- Stop Lustre, umount all servers. - Format a suitable disk partition on the new hardware, using the same mkfs-options as for the original MDT. - Mount the original MDT: mount -t ldiskfs /dev/sdb1 /mnt - Mount the target partition: mount -t ldiskfs -O ext_attr /dev/sdb1 /mnt - Copy the data: rsync -Xav oldserver:/mnt/ newserver:/mnt - Umount partitions, restart MGS - Mount new MDT This procedure was described by Jim Garlick on this list. You might note that I used the mount option "-O ext_attr" only on the target machine: my mistake perhaps, but no visible problems. In fact, I haven't found this option mentioned in any man page or on the net. Nevertheless, my mount command did not complain about it. So I wonder whether it is necessary at all - I seem to have extracted the attributes from the old MDT all right, without this mount option - ? My main question is whether this is a correct procedure for MDT backups, or rather copies. I'm investigating this because our production MDT seems to have a number of problems. In particular the underlying file system is in bad shape, fsck correcting a large number of ext3-errors, incorrect inodes and so forth. We want to verify that it is not a hardware issue - bit-flipping RAID controller, silent "memory corruption", whatever. We have a DRBD-mirror of this MDT running, but of course DRBD just reproduces all errors on the mirror. Copying from one ldiskfs to another should avoid that? The traditional backup method of getting the EAs and tar-ing the MDT doesn't finish in finite time. It did before, and the filesystem has since grown by a mere 40GB of data, so it shouldn't take that much longer - certainly another indication that there is something wrong. Of course I have yet to see whether "rsync -Xav" does much better on the full system ;-) Hm, not sure whether this all makes sense. The system runs Debian Etch, kernel 2.6.22, Lustre 1.6.7.1 Regards, Thomas _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
