Using RAID5 on an HP 3000
January 21, 2020
By Gilles Schipper
RAID storage, including a low-cost MOD20 array, can improve a 3000's performance. Here are a few things to consider if you will be acquiring a MOD20.
Although possible, I would not recommend utilizing RAID5 LUNs in an HP 3000 environment — unless your greatest priority is to maximize disk space availability at the expense of performance.
RAID5 offers fail-safe functionality over a group of disks (minimum of three) by means of one disk of the RAID5 disk being allocated as a parity disc. The benefit of RAID5 over RAID1 is that it results in a greater amount of overall usable disk space than RAID1. However, it performs poorly in an HP 3000 environment, and cannot be booted from if specified as the system disk (LDEV 1).
Although the supported maximum memory configuration of each Storage Processor (SP) unit is 64MB, 128MB works best (although not all of it can be used).
Each SP has 4 memory slots. You can maximize the performance of the MOD20 by populating each SP with four 32MB memory SIMMs, 72-pin, FPM with parity, 60ns.
The NIKE MOD20 is a very capable and useful solution to the fragile environment afforded by a JBOD environment — particularly because most 3000 JBOD disk systems tend to be very mature and consequently relatively unreliable and prone to failure.
And, although the MOD20 disk system itself is also quite long in the tooth, it’s got built-in fail-safe mechanisms. Also, the MOD20 would appeal to those with very limited budgets, since the devices are quite inexpensive in the used-equipment market.
There are other, more advanced RAID systems that also support the HP 3000 environment. These include the HP Autoraid12H system, various VA7400 systems, some of the HP XP-family members, as well as EMC systems. This list is in order of increasing cost, for the most part.
The bottom line: if you are not already utilizing RAID technology for your 3000, now would be a good time to consider it seriously.