Maximum Disc Replacement for Series 9x7s
July 21, 2014
Software vendors, as well as in-house developers, keep Series 9x7 servers available for startup to test software revisions. There are not very many revisions to MPE software anymore, but we continue to see some of these oldest PA-RISC servers churning along in work environments.
9x7s, you may ask -- they're retired long ago, aren't they? Less than one year ago, one reseller was offering a trio for between $1,800 (a Series 947) and $3,200. Five years ago this week, tech experts were examining how to modernize the drives in these venerable beasts. One developer figured in 2009 they'd need their 9x7s for at least five more years. For the record, 9x7s are going to be from the early 1990s, so figure that some of them are beyond 20 years old now.
"They are great for testing how things actually work," one developer reported, "as opposed to what the documentation says, a detail we very much need to know when writing migration software. Also, to this day, if you write and compile software on 6.0, you can just about guarantee that it will run on 6.0, 6.5, 7.0 and 7.5 MPE/iX."
Some of the most vulnerable elements of machines from that epoch include those disk drives. 4GB units are installed inside most of them. Could something else replace these internal drives? It's a valid question for any 3000 that runs with these wee disks, but it becomes even more of an issue with the 9x7s. MPE/iX 7.0 and 7.5 are not operational on that segment of 3000 hardware.
Even though the LDEV1 drive will only support 4GB of space visible to MPE/iX 6.0 and 6.5, there's always LDEV2. You can use virtually any SCSI (SE SCSI or FW SCSI) drive, as long as you have the right interface and connector.
There's a Seagate disk drive that will stand in for something much older that's bearing an HP model number. The ST318416N 18GB Barracuda model -- which was once reported at $75, but now seems to be available for about $200 or so -- is in the 9x7's IOFDATA list of recognized devices, so they should just configure straight in. Even though that Seagate device is only available as refurbished equipment, it's still going to arrive with a one-year warranty. A lot longer than the one on any HP-original 9x7 disks still working in the community.
But much like the 9x7 being offered for sale this year, five years later HP is still manufacturing computers, including its Unix and Linux replacement systems for any 3000 migrating users.
So to refresh drives on the 9x7s, configure these Barracuda replacement drives in LDEV1 as the ST318416N -- it will automatically use 4GB (its max visible capacity) on reboot.
As for the LDEV2 drives, there are no real logical size limits, so anything under 300GB would work fine -- 300GB was the limit for MPE/iX drives until HP released its "Large Disk" patches for MPE/iX, MPEMXT2/T3. But that's a patch that wasn't written for the 9x7s, as they don't use 7.5.
Larger drives were not tested for these servers because of a power and heat dissipation issue. Some advice from the community indicates you'd do better to not greatly increase the power draw above what those original equipment drives require. The specs for those HP internal drives may be a part of your in-house equipment documentation. Seagate offers a technical manual for the 18GB Barracuda drive at its website, for power comparisons.