Zpool wizard

Pools are used for grouping disks that belong to storage.

1. CREATE DATA GROUP - provides information of all hard drives that are connected to the storage server. To add the first Data Group to your zpool, please select disks on the list on the left, select the     redundancy type and click the "Create group" button.

Available redundancies for groups are:

• Single - each disk works as a single drive.
• Mirror - all data that are stored on disk "A" will be automatically mirrored to the disk "B". At least two disks are needed for creating a mirror. There are two options:
  • Mirror (Single Group) - all the disks will be assigned in one mirrored group.
  • Mirror (Multiple Groups) - the disks will be assigned in mirrors of two disks in multiple groups.
• RAIDZ-1 - one disk can fail per RAIDZ-1 group in order for the whole group to work correctly. A minimum of 3 disks should be used in RAIDZ-1 group.
• RAIDZ-2 - two disks can fail per RAIDZ-2 group in order for the whole group to work correctly. A minimum of 4 disks should be used in RAIDZ-2 group.
• RAIDZ-3 - three disks can fail per RAIDZ-3 group in order for the whole group to work correctly. A minimum of 5 disks should be used in RAIDZ-3 group.

2. CREATE WRITE LOG - allows configuring the write log function, using a redundancy level (mirror or single drive). A separate-intent log device. If more than one log device is specified, then writes are load-balanced between devices. Log devices can be mirrored. However, raidz vdev types are not supported for the intent log.

3. CREATE READ CACHE - A device used to cache storage pool data. A cache device cannot be configured as a mirror or raidz group. These devices provide an additional layer of caching between main memory and disk. For read-heavy workload, where the working set size is much larger than what can be cached in the main memory, using cache devices allow much more of this working set to be served from low-latency media. Using cache devices provides the greatest performance improvement for random read-workloads of mostly static content.

4. CREATE SPARE DISK - A special pseudo-vdev which keeps track of available spares for a pool. ZFS allows devices to be associated with pools as "spares". To create a pool with spares, specify a "spare" vdev with any number of devices. Once a spare replacement is initiated, a new "spare" vdev is created within the configuration that will remain there until the original device is replaced. If a pool has a shared spare that is currently being used, the pool cannot be exported since other pools may use this shared spare, which may lead to potential data corruption. Spares cannot replace log devices.

5. ZPOOL PROPERTIES - allows defining a pool called as a " Zpool name ". This name of the zpool will be used in the system.

6. SUMMARY - sumarizes the zpool configuration: groups of disks that are used for data and other groups of disks, used for caching, spare, etc.