XFS Filesystem Howto
The following is the procedure to migrate from a non-xfs filesystem (e.g. ex2 or ex3) to xfs without loosing data. The DPM nameserver uses the diskserver and the filepath therein to source files. Hence the filesystem format can be altered without affecting the DPM nameservers ability to locate files. 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
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 headnode
mount -o remount ro "each filesystem mountpoint"
- Tar up all the data from each individual filesystem. e.g. if there are n filesystems then create n tarballs. And 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. from the source machine (dpm headnode)
tar -cvf filepath/dpmdata | ssh user@destination cat \> dpmdata.tar
from the destination (storage machine)
ssh user@source tar -cvf - filepath/dpmdata > 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. from the source (storage machine)
tar -xpvf dpmdata.tar | ssh user@destination \> filepath/dpmdata
from the destination (dpm headnode)
ssh user@source tar -xpvf dpmdata.tar - > filepath/dpmdata