ZFS Tools

Rust rewrites of some shell and Ruby scripts I've been using for years. Some of what they do is now replicated in illumos.

zfs-real-usage

The way ZFS reports space can be a little confusing: zfs-real-usage tells you very clearly how much real disk space is occupied by your filesystems and snapshots. It sorts from the least to the most, and takes no options. If you want to filter, use rg or grep.

This is useful when you need to clear some space and some deeply buried snapshot is hogging a stack of room.

zfs-remove-snaps

Batch-removes ZFS snapshots.

• -f (--files) specifies that arguments are files. The program will work out which filesystems contain them. If you don't supply -f or -s, then all arguments are assumed to be ZFS filesystem names.

• -a (--all-datasets) tells the program to remove snapshots under all filesystems whose name matches any of the arguments. So -a logs would remove snaps for rpool/logs rpool/application/logs and tank/logs.

• -s (--snaps) means that all arguments are snapshot names. -s monday would remove all @monday snapshots anywhere in your hierarchy.

• -r (--recurse) recurses down the filesystem tree. If you have a pool called tank, -r tank would remove every snapshot it. This doesn't use ZFS's native -r, preferring to work out its own matches. This means you can use...

• -o LIST (--omit-fs) tells the program NOT to delete snapshots belonging to filesystems included in a n comma-separated list. Basic wildcards are supported, so\*keep,\*these\*,safe\*would not remove snapshots from any filesystems whose names end withkeep, or contain these, or begin withsafe.

• -O LIST (--omit-snaps) tells the program NOT to delete any snapshots whose names are included in a comma-separated list. You can use -o and -O together, but you can't use them when your arguments are snapshots or dataset names. i.e. with -s or -a.

• -n (--noop) makes the program print the zfs commands it would run, without actually running them.

• -v (--verbose) prints the zfs commands as they are run.

zfs-rogue-snaps

I have a snapshot naming scheme. zfs-rogue-snaps finds snapshots which do not fit that scheme. It probably won't be useful to anyone else, unless, perhaps, if you use...

zfs-snap

This program takes ZFS snapshots with an automated naming scheme.

• -t (--type) specifies the format of the snapshot name, Choose from day, which uses the day of the week, lowercased; month; date, which is formatted YYYY-mm-dd; time, formatted HH:MM; and now, which formats the current time as YYYY-mm-dd_HH:MM:SS.

• -f (--files`) has the program work out the ZFS filesystem name from a file path.

• -r (--recurse) recurses down ZFS hierarchies.

• -o (--omit) lets you specify filesystems which will NOT be snapshotted. This is applied after any recursion is calculated. You can use asterisks as wildcards in the same way as zfs-remove-snaps.

• -n (--noop) makes the program print the zfs commands it would run, without actually running them.

• -v (--verbose) prints the zfs commands as they are run.

Existing snapshots with the same names are removed.

zfs-touch-from-snap

Compares a live filesystem with one of its snapshots, and modifies the mtimes of the live files, using the snapshot contents as a reference.

• -s SNAPSHOT (--snapname) tells the program which snapshot to use. If you do not supply one, it will assume you have snapshots monday through sunday, and use yesterday's.

• -n (--noop) prints the actions it would take, without actually taking them.

• -v (--verbose) prints the actions it takes, as it takes them.

zp

Promotes files from a ZFS snapshot. Specify the file inside the snapshot directory, for instance zp /tank/.zfs/snapshot/monday/my/example/file, and it will copy my/example/file relative to the mounted filesystem root. It is a less-useful companion to zr.

zp is automatically recursive: promoting a directory promotes it all the way down.

• -N (--noclobber) by default, zp will overwrite any existing files. Use this option to preserve them.

• -n (--noop) prints actions without actually taking them.

• -v (--verbose) prints actions as they are taken.

zr

Recovers files from ZFS snapshots. Give it a filename, and it will find all copies of said file in snapshots, and display them in a list with their size and time of last modification. Pick the one you want, and it will be copied into its correct place in the live filesystem. Works on files and directories.

• -a (--auto) will make zr recover the most recently modified file rather than showing you a list and prompting for input,

• -N (--noclobber) by default, zr will overwrite any existing files. Use this option to preserve them. This can be useful if you want to recover lost files in a directory without getting back old versions of things which have changed.

• -n (--noop) prints actions without actually taking them.

• -v (--verbose) prints actions as they are taken.

Here is an article about the original Ruby versions of zr and zp.