Hardware Installation
PixelStor 300e Hardware Installation Manual
Rev. 1, May 2013
2-9
300e to an existing system, the PS300e must be the last enclosure in the daisy chain.
PixelStor 300e
enclosures follow the same concept of “disk groups” used for the PixelStor 5000.
A “disk group” (DG) is composed of an associated group of disks with similar RAID properties. All
DGs must be assigned a RAID level. The system supports RAID 0, 1,5,10. The following rules
must be followed when creating DGs for a PixelStor 5000/PS300e:
A DG can span across interconnected PixelStor 5000 and PixelStor 300e systems.
Drives within a DG can reside in any order across any of the enclosures in a system.
Capacity of a DG can be expanded by adding disks from the available pool of global spare
disks. (Adding disks to a disk group may require multiple disks.)
DGs can be accessed by either controller, but must be assigned a primary controller.
Drives not assigned to a disk g
roup will be classified as “Global Spares”
Global spare(s) can reside on any of the 4 interconnected chassis to protect any DG within
the four chassis. A Global Spare cannot be added to RAID 0 DG.
Failed Disks or disks disassociated from their disk group w
ill be classified as “Orphans” by the
system.
It is recommended not to build a RAID 5 DG beyond 8 drives. The bigger the RAID 5 DG, the
higher the probability for multi-drive failures. Multi-drive failure is not protected by RAID 5.
To build RAID 5 DG bigger than 8 drives, use the systems capacity expansion feature to
concatenate a second RAID 5 disk group to the first. You can do this multiple times up to a
maximum of 24 drives.
Disk Group (DG) Parameters
RAID 0
RAID 5
RAID 1
RAID 1+0
1.
Minimum # of Drives per DG
2
3
2
4
2.
Maximum # of Drives per DG
Capacity
24
24
24
24
3.
DGs Allowed per System
1-4
1-4
1-4
1-4
4.
RAID Level Allowed per DG
1
1
1
1
5.
Drives Must be Added in
Singles
Singles
Pairs
Pairs
6.
Global Spare Capability
N/A
Yes
Yes
Yes
7.
Access DG by both Controllers
Yes
Yes
Yes
Yes
To improve the utilization of the available storage capacity and ensure reliability, it is
recommended that all disk drive modules within a DG be the same size and from the
same manufacturer. This is because for each RAID Group, the system scales down
to the size of the smallest drive (except for RAID 0).
