zfs snapshot size

The actual meta-data of snapshots are negligible. As a copy-on-write file system, ZFS snapshots only require space for modified data; creating a snapshot does not immediately duplicate everything. If you have a snapshot of given size, and then add or modify files summing up to 100GB, the snapshot will "cost" you 100GB.

How do I view ZFS snapshots?
What is a ZFS snapshot?
How do ZFS snapshots work?
How do I check my free space in ZFS pool?
What is refer in ZFS list?
What is ZFS?
How do you delete a snapshot on ZFS?
How do I delete a dataset in ZFS?
How do you destroy ZFS in pool?
How do I defrag ZFS?
What is ZFS compression?
How do I rename a ZFS mount point?

How do I view ZFS snapshots?

Snapshots of file systems are accessible in the . zfs/snapshot directory within the root of the file system. For example, if tank/home/cindy is mounted on /home/cindy, then the tank/home/cindy@thursday snapshot data is accessible in the /home/cindy/.

What is a ZFS snapshot?

zfs snapshot is a read-only copy of zfs file system or volume. They consume no extra space in the zfs pool and can be created instantly. They can be used to save a state of file system at particular point of time and can later be rolled back to exactly same state.

How do ZFS snapshots work?

A snapshot is a read-only copy of a file system or volume. Snapshots can be created almost instantly, and they initially consume no additional disk space within the pool. Snapshots consume disk space directly from the same storage pool as the file system or volume from which they were created. ...

How do I check my free space in ZFS pool?

You can use the zpool list command to display basic information about pools.
...
Displaying ZFS Storage Pool Command History

The log cannot be disabled.
The log is saved persistently on disk, which means that the log is saved across system reboots.
The log is implemented as a ring buffer.

What is refer in ZFS list?

zpool

Let's create some test pool: ...
NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT. ...
The reference data (REFER) means how many data are REFERENCED to the particular dataset (not stored in the dataset). ...
If we were to start writing to the dataset ztank/mytest the USED and REFER amount will be increased:

What is ZFS?

ZFS is a local file system and logical volume manager created by Sun Microsystems Inc. to direct and control the placement, storage and retrieval of data in enterprise-class computing systems. ... Deduplication - a process that eliminates redundant copies of data and reduces storage overhead.

How do you delete a snapshot on ZFS?

Note: To create a recursive snapshot, use zfs “snapshot -r” and the snapshot name (for example, zfs snapshot -r datapool/home@now). To destroy a ZFS snapshot, use the zfs destroy command followed by the snapshot name. In the example below, you are destroying the snapshot named datapool/home/user@friday.

How do I delete a dataset in ZFS?

To destroy a ZFS file system, use the zfs destroy command. By default, all of the snapshots for the dataset will be destroyed. The destroyed file system is automatically unmounted and unshared.

How do you destroy ZFS in pool?

Pools are destroyed by using the zpool destroy command. This command destroys the pool even if it contains mounted datasets. Be very careful when you destroy a pool. Ensure that you are destroying the right pool and you always have copies of your data.

How do I defrag ZFS?

The simplest way to “defragment” any file system (not just ZFS) is actually to copy the fragmented files off to some other storage, delete them from original, and then copy them back again.

What is ZFS compression?

Compression in ZFS is a pretty neat feature: it compresses your files on the fly and therefore lets you store more data using limited storage. At any time time you can request ZFS compression stats per ZFS pool or volume and it will show you exactly how much space you're saving.

How do I rename a ZFS mount point?

File systems can be renamed by using the zfs rename command.
...
With the rename subcommand, you can perform the following operations:

Change the name of a file system.
Relocate the file system within the ZFS hierarchy. ...
Change the name of a file system and relocate it within the ZFS hierarchy.