Choosing the Right Disk Technology in a High Availability Environment DRAFT Version 2.0, August 1996

Table E: Maximum Disk Capacity using F/W SCSI Disk Arrays
SPU Model Using Disk Arrays in RAID Using Disk Arrays in RAID
Level 5 Level 0/1
DRAFT -- Revision 2.0
August 22, 1996Page 34
Exx 1,920 GB 1,190 GB
Table F shows the maximum disk capacity supported on the various HP disk arrays at
each supported RAID level.
Table F: Maximum Supported Usable Capacities
RAID HP-FL Arrays F/W SCSI Arrays F/W SCSI HA AutoRAID Disk
level (FLDAs) (SCSI DAs) Arrays (HADAs) Arrays
0* N/A N/A 42 GB N/A
1 N/A N/A 21 GB **
0/1 N/A N/A 21 GB N/A
3 8 GB 8 GB N/A N/A
5 N/A 8 GB 33.6 GB 18.5 GB
Ind* 10 GB 10 GB 42 GB N/A
NOTES:
* Independent Mode is NOT a High Availability Solution due to the lack
of data redundancy
** The amount of disk capacity in RAID 1 mode is configurable and
subtracts from the amount available for RAID 5
PERFORMANCE COMPARISONS
The issue of the performance of standalone disks in comparison to RAID disk arrays is
very complex. Actual performance depends upon:
use of LVM versus non-LVM managed disks
whether hardware or software striping is used
whether hardware or software data protection is used
I/O size
ratio of reads to writes (read or write intensity)
sequential or random access patterns