![]() This means the only way to restore data from a snapshot is to actually copy (rsync?) it over. Snapshots cannot be rolledback/merged at the moment (see ).Once you run out of space, the snapshot is corrupt and cannot be repaired. if you have a snapshot it is very easy to run out of space.This effect is especially horrid if root is on lvm2 (because waiting for the root device will timeout and system doesn't boot) if you have a big(ish) filesystem that has a snapshot, boot time will be delayed with literally tens of minutes while the disk will be churning and churning during import of the volume group.if you have a big(ish) filesystem that has a snapshot, write performance is horribly degraded.The only exception I'll make now is my own personal mailserver/webserver backup, where I'll do overnight backups using an ephemeral snapshot, that is always equal the size of the source fs, and gets deleted right afterwards. I've stopped using them altogether - it's just too dangerous. However, I can no longer count the different failure modes I encountered when using snapshots. I've been running exclusively on LVM2 and xfs for the last 6 years on my servers (at home even since zfs-fuse is just plain too slow). Using lvm snapshots and xfs on live filesystems is a recipe for disaster especially when using very large filesystems. This is all just the tip of the iceberg, I would highly recommend getting your hands on an install of Open Solaris and trying this out.Įdit: This is very old, Open Solaris has been discontinued, the best way to use ZFS is probably on Linux, or FreeBSD.įull disclosure: I used to be a Sun storage architect, but I haven't worked for them in over a year, I'm just excited about this product. Incremental send/receive: # zfs send -i | ssh otherserver "zfs receive -v filesystem/home/user"Ĭaching devices: # zpool add filesystem cache ssddev It supports simple to create copy-on-write snapshots that can be live-mounted: # zfs snapshot cd filesystem/home/user/.zfs/snapshot/tuesdayįilesystem cloning: # zfs clone filesystem/home/user2įilesystem send/receive: # zfs send | ssh otherserver "zfs receive -v filesystem/home/user" It's also got compression, snapshots, cloning, filesystem send/receive, and cache devices (those fancy new SSD drives) to speed up indexing meta-data.Ĭompression: #zfs set compression=on filesystem/home The command structure is very thoughtfully laid out, and intuitive. ![]() ZFS will give you advantages beyond software RAID.
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