Qnap ts-431 Инструкция по эксплуатации онлайн [68/344] 162186

This function can reduce the rebuilding duration after a crash, or time length required

to remove/re-add a hard disk. This feature does not improve the disk read/write

performance and might even cause a small degradation in performance. However, if an

array has a bitmap, a hard disk can be removed and re-added, and only changes in

blocks need to be made since the removal (as recorded in the bitmap) can be re-

synced. To enable a bitmap, select a RAID group and click "Manage" > "Enable Bitmap"

and then "OK". To disable a bitmap, select a RAID group and click "Manage" > "Disable

Bitmap" (only available after a bitmap has been enabled) and then "OK".

Note:

The bitmap support is only available for RAID 1, RAID 5, RAID 6 and RAID 10.

Recovering Failed RAID Disk Volumes

This function can recover failed RAID disk volumes from the "Inactive" status to the

normal state (RAID 1, RAID 5, RAID 6 and RAID 10 will be recovered to the degraded

mode; RAID 0 and JBOD will be recovered to the normal state.) Before recovering a

failed disk volume, please confirm that all hard disks of that disk volume are properly

seated in the NAS drive bays. Once recovery is completed, back up your data on the

disk(s) immediately in case the disk volume fails again.

Inactive RAID disk volumes can be recovered only if the minimal number of healthy disks

required for the RAID configuration is available on the NAS. For example, in a RAID 5

configuration with three hard disks in the array, at least two healthy hard disk drives

are required available in the NAS for volume recovery. If not, this RAID volume cannot

be recovered. Refer to the following table for the minimal number of hard disks required

to recover each RAID group:

RAID

group

Minim al num ber of hard disks required for recovery

RAID 1

RAID 5

Number of disks - 1

RAID 6

Number of disks - 2

RAID 10

Number of disks / 2; (1 hard drive per RAID 1)

Follow the steps below to recover a failed RAID group:

1. Select a failed RAID group.

2. Click "Manage" > "Recover".