iSCSI GbE to SAS/SATA II RAID Subsystem
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User Manual
NOTE: “Set dedicated spare” is not available if there is no RG, or if
RG is set to RAID 0 or JBOD, because user can not set dedicated
spare disk to RAID 0 & JBOD.
Sometimes, rebuild is called recover; they are the same meaning. The following table
is the relationship between RAID levels and rebuild.
RAID 0
Disk striping. No protection for data. RG fails if any hard drive
fails or unplugs.
RAID 1
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.
N-way
mirror
Extension to RAID 1 level. It has N copies of the disk. N-way
mirror allows N-1 hard drives failure or unplugging.
RAID 3
Striping with parity on the dedicated disk. RAID 3 allows one
hard drive failure or unplugging.
RAID 5
Striping with interspersed parity over the member disks. RAID 5
allows one hard drive failure or unplugging.
RAID 6
2-dimensional parity protection over the member disks. RAID 6
allows two hard drives failure or unplugging. If it needs to rebuild
two hard drives at the same time, it will rebuild the first one,
then the other in sequence.
RAID 0+1
Mirroring of RAID 0 volumes. RAID 0+1 allows two hard drive
failures or unplugging, but at the same array.
RAID 10
Striping over the member of RAID 1 volumes. RAID 10 allows
two hard drive failure or unplugging, but in different arrays.
RAID 30
Striping over the member of RAID 3 volumes. RAID 30 allows
two hard drive failure or unplugging, but in different arrays.
RAID 50
Striping over the member of RAID 5 volumes. RAID 50 allows
two hard drive failures or unplugging, but in different arrays.
RAID 60
Striping over the member of RAID 6 volumes. RAID 40 allows
four hard drive failures or unplugging, every two in different
arrays.
JBOD
The abbreviation of
“J
ust a
B
unch
O
f
D
isks
”
. No data protection.
RG fails if any hard drive failures or unplugs.
