Mirroring Pool Disks
Fault tolerant pools can be created to add another dimension of high availability by mirroring the physical disks in pools. Mirroring pool disks is also useful when a disk needs to be replaced for a reason other than disk failure, such as when migrating data to new storage. If a disk is mirrored, then one of the disks can be removed even if virtual disks have been created from that pool.
- The size of the mirror disk must be equal to or larger than the physical disk. We recommend using a disk of equal size for a mirror because any additional space will not be usable unless the smaller mirror disk is later removed from the disk pool, such as when migrating data to new storage. The menu option will be greyed out if there are no qualified candidates.
- Adding a pool mirror does not consume capacity unless the mirror added is larger than the physical disk it is mirroring. In which case, capacity will be increased by the difference in size.
- The sector size of mirrored pool disks must be the same.
- Pool mirrors will prevent the pool from being authorized as an SMPA pool. See Shared Multi-port Array Support.
- See Removing Physical Disks from Pools for instructions to remove a pool mirror.
To add mirrors to pool disks:
- In DataCore Servers panel, expand the disk pool containing the disk to mirror.
(Alternatively, pool mirror disks can also be added from the Disk Pools details page>Physical Disks tab.)
- Right-click on the disk and select Add Mirror Disk, then select an available disk from the list. The disk will be listed under the same pool in the panel.
- A full synchronization of the pool disk mirror begins.
A computer restart or stopping the DataCore Server which owns the disk pool will interrupt the process and cause the full mirror synchronization to restart.
To view information about disk pool mirrors:
Disk pool mirrors can be identified in Disk Pool Details page>Physical Disks tab, both disks will be listed under the Name column in this format: "Pool Member | Pool Mirror". Mirror state and status are displayed in the tab. Recovery of the mirror can be monitored under the Mirror State column and by clicking on the disks listed and viewing the information in the Physical Disks Summary at the bottom of the tab. (The estimated time for recovery will fluctuate because it is continuous recalculated and based on the network traffic at the time of calculation.)
In the DataCore Servers panel, under the disk pools, all physical disks and associated pool mirrors are also listed in this format: "Pool Member | Pool Mirror".
To view details for a pool disk mirror:
- Open the DataCore Server Details page.
- In the Physical Disks tab, each disk is listed separately. Double-click the mirror to open the details page for the mirror.