ZFS Command Reference
Pool Management (ZPOOL Commands)
| Command | Description | Example Usage |
|---|---|---|
zpool create | Creates a new ZFS storage pool. | zpool create mypool /dev/sda |
zpool destroy | Destroys an existing pool. This action is irreversible. | zpool destroy mypool |
zpool status | Displays the status of all ZFS pools and their associated devices. | zpool status |
zpool list | Lists all active pools with their basic properties. | zpool list |
zpool add | Adds a new device to an existing pool. | zpool add mypool /dev/sdb |
zpool remove | Removes a device from an existing pool. | zpool remove mypool /dev/sdb |
zpool scrub | Initiates a scrub to verify data integrity and correct errors if necessary. | zpool scrub mypool |
zpool import | Imports an existing pool. | zpool import mypool |
zpool export | Exports a pool, making it unavailable for use on the current system. | zpool export mypool |
zpool upgrade | Upgrades the pool to the latest ZFS version. | zpool upgrade mypool |
zpool history | Displays a history of all operations performed on the pool. | zpool history mypool |
zpool iostat | Shows input/output statistics for each pool. | zpool iostat mypool |
Dataset Management (ZFS Commands)
| Command | Description | Example Usage |
|---|---|---|
zfs create | Creates a new dataset within a pool. | zfs create mypool/mydataset |
zfs destroy | Destroys a dataset. This action is irreversible. | zfs destroy mypool/mydataset |
zfs list | Lists all datasets in a pool along with properties such as used and available space. | zfs list |
zfs get | Displays specific properties of datasets. | zfs get compressratio mypool/mydataset |
zfs set | Sets a property for a dataset. | zfs set compression=lz4 mypool/mydataset |
zfs mount | Mounts a dataset. | zfs mount mypool/mydataset |
zfs unmount | Unmounts a dataset. | zfs unmount mypool/mydataset |
zfs rename | Renames a dataset. | zfs rename mypool/mydataset mypool/newdataset |
zfs clone | Creates a writable clone of a snapshot. | zfs clone mypool@mysnapshot mypool/myclone |
zfs promote | Promotes a clone to a full dataset, allowing it to be modified independently. | zfs promote mypool/myclone |
Snapshot Management
| Command | Description | Example Usage |
|---|---|---|
zfs snapshot | Creates a snapshot of a dataset or volume. | zfs snapshot mypool/mydataset@mysnapshot |
zfs list -t snapshot | Lists all snapshots in the system. | zfs list -t snapshot |
zfs destroy | Destroys a snapshot. This action is irreversible. | zfs destroy mypool/mydataset@mysnapshot |
zfs rollback | Rolls back a dataset to a specific snapshot. | zfs rollback mypool/mydataset@mysnapshot |
zfs send | Sends a snapshot to another location, usually for backup purposes. | zfs send mypool/mydataset@mysnapshot > /backup/mysnapshot |
zfs receive | Receives a snapshot from a send operation. | zfs receive mypool < /backup/mysnapshot |
Performance Tuning
| Command | Description | Example Usage |
|---|---|---|
zfs set atime=off | Disables access time updates, improving performance for certain workloads. | zfs set atime=off mypool/mydataset |
zfs set recordsize | Sets the record size for a dataset, which can be adjusted to optimize performance. | zfs set recordsize=128K mypool/mydataset |
zfs set compression | Enables compression for a dataset, improving space efficiency. | zfs set compression=lz4 mypool/mydataset |
zfs set dedup=on | Enables deduplication, though it can impact performance. | zfs set dedup=on mypool |
zfs set sync=disabled | Disables synchronous writes, which can improve performance but may risk data loss in the event of a crash. | zfs set sync=disabled mypool/mydataset |
zpool iostat | Displays I/O statistics, useful for monitoring performance. | zpool iostat mypool |
zpool set cachefile | Configures the location of the ZFS pool cache to improve performance for multiple pools. | zpool set cachefile=/etc/zfs/zpool.cache mypool |
Backup and Recovery
| Command | Description | Example Usage |
|---|---|---|
zfs send | Sends a snapshot to another location for backup. | zfs send mypool/mydataset@mysnapshot > /backup/mysnapshot |
zfs send -i | Sends an incremental snapshot (only the changes since the last snapshot). | zfs send -i mypool@oldsnapshot mypool@newsnapshot > /backup/incremental |
zfs receive | Receives a snapshot from a zfs send operation. | zfs receive mypool < /backup/mysnapshot |
zpool import | Imports a pool from another system, typically used in recovery scenarios. | zpool import mypool |
zpool export | Exports a pool so it can be imported on another system. | zpool export mypool |
zpool scrub | Initiates a scrub to verify data integrity and correct errors. | zpool scrub mypool |
Troubleshooting
| Command | Description | Example Usage |
|---|---|---|
zpool status | Displays the status of the pool and identifies any errors or degraded devices. | zpool status |
zpool clear | Clears error counts and resumes normal operation after a device failure. | zpool clear mypool |
zfs list -o | Displays dataset properties to help diagnose issues. | zfs list -o name,used,available |
zpool iostat | Provides I/O statistics, which can help identify performance bottlenecks. | zpool iostat mypool |
zpool events | Displays events related to the ZFS pool, such as device failures or errors. | zpool events |
zdb | ZFS debugger for advanced troubleshooting. | zdb -e mypool |