When rebuilding, the status of PD/VG/UDV is “R”; and “R%” in UDV will display the ratio in percentage. After complete rebuilding, “R” and “DG” will disappear. VG will become complete one.

When rebuilding, the status of PD/VG/UDV is “R”; and “R%” in UDV will display the ratio in percentage. After complete rebuilding, “R” and “DG” will disappear. VG will become complete one.

Tips

The list box doesn’t exist if there is no VG or only VG of RAID 0, JBOD. Because user cannot set dedicated spare disk for these RAID levels.

Sometimes, rebuild is called recover; these two have the same meaning. The following table is the relationship between RAID levels and rebuild.

RAID 0

RAID 1

N-way mirror

RAID 3

RAID 5

RAID 6

RAID 0+1

RAID 10

RAID 30

Disk striping. No protection of data. VG fails if any hard drive fails or unplugs.

Disk mirroring over 2 disks. RAID 1 allows one hard drive fails or unplugging. Need one new hard drive to insert to the system and rebuild to be completed.

Extension to RAID 1 level. It has N copies of the disk. N-way mirror allows N-1 hard drives fails or unplugging.

Striping with parity on the dedicated disk. RAID 3 allows one hard drive fail or unplugging.

Striping with interspersed parity over the member disks. RAID 5 allows one hard drive fail or unplugging.

2-dimensional parity protection over the member disks. RAID 6 allows two hard drives fails or unplugging. If it needs to rebuild two hard drives at the same time, it will rebuild the first one, then the other by sequence.

Mirroring of the member RAID 0 volumes. RAID 0+1 allows two hard drives fails or unplugging, but at the same array.

Striping over the member RAID 1 volumes. RAID 10 allows two hard drives fails or unplugging, but at different arrays.

Striping over the member RAID 3 volumes. RAID 30 allows two hard drives fails or unplugging, but at different arrays.

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APC SCSI-SATA II manual Tips, RAID RAID N-way mirror RAID RAID RAID RAID 0+1 RAID RAID