Zvols

How to create a Zvol.

  3 minute read

A ZFS pool must be created first to create a Zvol. See Creating a new ZFS Pool.



To create a Zvol in the desired pool, go to Storage > Pools then click   and Add Zvol.

To quickly create a Zvol with the default options, enter a name for the Zvol, a size, and click SAVE. To modify more advanced settings of the Zvol click ADVANCED MODE. Zvol options can also be edited after creation. To edit a Zvol, click   and Edit Options.

zvol Configuration Options

SettingValueAdvanced ModeDescription
zvol namestringEnter a short name for the zvol. Using a zvol name longer than 63-characters can prevent accessing zvols as devices. For example, a zvol with a 70-character filename or path cannot be used as an iSCSI extent. This setting is mandatory.
CommentsstringEnter any notes about this zvol.
Size for this zvolintegerSpecify size and value. Units like t, TiB, and G can be used. The size of the zvol can be increased later, but cannot be reduced. If the size is more than 80% of the available capacity, the creation will fail with an “out of space” error unless Force size is also enabled.
Force sizecheckboxBy default, the system will not create a zvol if that operation will bring the pool to over 80% capacity. While NOT recommended, enabling this option will force the creation of the zvol.
Syncdrop-down menuSets the data write synchronization. Inherit inherits the sync settings from the parent dataset, Standard uses the sync settings that have been requested by the client software, Always waits for data writes to complete, and Disabled never waits for writes to complete.
Compression leveldrop-down menuCompress data to save space. Refer to Compression for a description of the available algorithms.
ZFS Deduplicationdrop-down menuDo not change this setting unless instructed to do so by your iXsystems support engineer.
SparsecheckboxUsed to provide thin provisioning. Use with caution as writes will fail when the pool is low on space.

Click   (Options) next to the desired zvol in Storage > Pools to access the Delete zvol, Edit Zvol, Create Snapshot, and, for an existing zvol snapshot, Promote Dataset options.

Similar to datasets, a zvol name cannot be changed.

Choosing a zvol for deletion shows a warning that all snapshots of that zvol will also be deleted.

Advanced Options

| Setting | Value | Advanced Mode | Description | | Block size | drop-down menu | ✓ | The default is Inherit, other options include, 4KiB, 8KiB, 16KiB, 32KiB, 64KiB, 128KiB,|


Last modified December 18, 2020: Update zvols.md (bb81ea05)