DPM Filesystm XFS Formatting Howto

The following is the procedure to migrate from a non-xfs filesystem (e.g. ext2 or ext3) to xfs without losing data.

The DPM nameserver uses the file server name and the file's path to source files. Hence the filesystem format can be altered without affecting the DPM nameservers ability to locate files, as long as the files are replaced in the same path.

DO NOT unmount the filesystem (umount /dev/...) from the dpm headnode and DEFINATELY DO NOT remove the dpm filesystems (e.g dpm-rmfs)

• Shutdown the DPM daemons on the headnode

 service dpm-gsiftp stop
 service srmv2 stop
 service srmv1 stop
 service dpm stop
 service rfiod stop
 service dpnsdaemon stop

and on each disk server

 service dpm-gsiftp stop
 service rfiod stop                                                                                                                             

and make sure there can be no more writing to the files on the disk server

 mount -o remount,ro /dev/fs /path                                                                                                                             

• Tar up all the data from each individual filesystem, i.e., if there are n filesystems then create n tarballs. Store the tarballs in a secure location.

The following examples assume the DPM filesystem mountpoint is /filepath/dpmdata.

The tarballing and moving can be done in one command on the disk server

 cd /
 tar -cvf /filepath/dpmdata | ssh -e none user@backup-host cat \> dpmdata.tar

• Verify the contents of each tarball.

 tar -tvf dpmdata.tar                                                                                                                             

• Format each filesystem to be xfs. see the XFS Kernel Howto.
• Unpack each tarball into the appropriate directory.

The moving and unpacking can be done in one command on the disk server

 cd /
 ssh -e none user@backup-host cat dpmdata.tar |  tar -xpvf -