In my experience, migrating/syncing the cpool/pool/pc folder using rsync (hard links in tact) isn't a practical exercise (but is technically possible).
The size of your cpool/pool/pc data set will have exponential implications on the time required to sync (even if no data changes hands). The significant latency in syncing comes from the computations required by rsync and the iops requirements at both sites to gather the metadata from disk (really high iops as it's all random and low sector count). If you are going to keep both sites in sync using rsync look at tuning your "vm/vfs_cache_pressure" to ensure your caching metadata over blocks (for faster syncs). Otherwise I would strongly recommend looking at another option (like block level replication drdb, or shipping filesystem snapshots in btrfs and zfs). On 21/12/2015 8:59 AM, Adam Goryachev wrote: > Il 17/12/2015 16:04, absolutely_f...@libero.it ha scritto: >>> Hi. >>> >>> let's say I can't use DRDB or mdadm at all. >>> If I sync every "pc", one by one, between two storage, this could be working >>> (even if suboptimal)? >>> I know that rsync is able to recognize hardlinks (-H) only in same session >>> (from manpage: " Note that rsync can only detect hard links between files >>> that >>> are inside the transfer set. "). >>> So I guess, on second storage disk occupation will be bigger. >>> Thank you very much. > >From memory, I think you could use rsync to copy the pool/cpool + one pc > directory, then run rsync again to copy the pool/cpool + second pc > directory, etc... This should preserve all hardlinks since the pc > directory is hardlinked to the pool, and you copy the pool on every run. > > Not sure if that data set will work well or not, depending on number of > files in your pool I guess, and also number of files per pc, and number > of backups retained. > > Regards, > Adam > ------------------------------------------------------------------------------ _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
