mangler@cit-vax.Caltech.Edu (System Mangler) (12/07/86)
In article <4647@mimsy.UUCP>, chris@mimsy.UUCP (Chris Torek) writes: > because our source machine is down with broken CDC 9771 drives.) More than one broken? Lately, this sounds typical of CDC drives in general. All four of our 9715's crashed in less than a year... So when the Emulex salesman was trying to sell us some CDC 9772's, I took particular note of the CDC 3-year HDA warranty. Given their record, does this mean that 9772's are reliable, or does it mean that CDC will replace the HDA lots and lots of times for free? Do the replacement HDA's carry the same warranty? I read in one of the DEC-watcher rags that CDC just introduced an even bigger drive, 1.3 gigabytes. No Emulex controller yet, so I assume that means that the transfer rate went up. (Why can't the controller makers keep up with the drives?!?). Is it worth a look? Don Speck speck@vlsi.caltech.edu {seismo,rutgers,ames}!cit-vax!speck
kehres@styx.UUCP (Tim Kehres) (12/08/86)
In article <1306@cit-vax.Caltech.Edu> mangler@cit-vax.Caltech.Edu (System Mangler) writes: >I read in one of the DEC-watcher rags that CDC just introduced an >even bigger drive, 1.3 gigabytes. No Emulex controller yet, so I >assume that means that the transfer rate went up. (Why can't the >controller makers keep up with the drives?!?). Is it worth a look? > >Don Speck speck@vlsi.caltech.edu {seismo,rutgers,ames}!cit-vax!speck To start with, I have absoloutely no connection with the folks that work with the disk drives, but I picked up some stuff at the latest Comdex that may be of interest. The drive that I believe you are referring to has the following specs (from the CDC sales literature): MODEL: XMD III SPECIFICATIONS ============== Drive Capacity (Mbytes) 1359 Disks 6 Disk surfaces 9.5 Tracks/surface 1420 Track density (TPI) 1280 Recording density 15,400 Rotation speed (r/min) 3600 Average latency (ms) 8.38 Seek time Single track (ms) 5 Average (ms) 16 Maximum (ms) 30 Interface SMD-E, IPI-2 Transfer rate (MHz) 24 (3 Mbytes/s) Data code NRZ MTBF (Hours) 30,000 Service life (Years) 5 The transfer rate quoted may be higher than some controllers are capable of, but this rate is by no means unique. The Century C2800 and Hitachi DK815-10 for example are also quoting similar transfer rates. Tim Kehres Control Data Corporaton / Lawrence Livermore National Laboratory ---------------------------------------------------------------- UUCP: {lll-crg,ihnp4!lll-lcc}!styx!kehres ARPA: kehres@lll-tis-b.ARPA AT&T: (415) 463-6852
chris@mimsy.UUCP (Chris Torek) (12/08/86)
>In article <4647@mimsy.UUCP> I mentioned >>... our source machine is down with broken CDC 9771 drives. In article <1306@cit-vax.Caltech.Edu> mangler@cit-vax.Caltech.Edu (System Mangler) writes: >More than one broken? Well, one for certain: it was reporting all sorts of crazy errors, and faulted once. The other one appears OK, except that the system no longer boots, halting with code `04' after loading and starting the kernel. Code 4 is `interrupt stack invalid or SCB cannot be read'; I have not yet figured out which one is occurring, or why. (It does not seem to be a clobbered vmunix, as all of the old working vmunixes do the same thing.) We have decided to take advantage of the enforced downtime to get Emulex to put new ROMs in our SC41/MS controller. They were promising new ROMs quite some time ago, to try to fix some problems I noted, but never sent any. We have DEC service on the 9771s, because another campus group had trouble with CDC service. Whether DEC know how to repair CDC drives remains to be seen, but it is unlikely they will be worse than CDC. -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690) UUCP: seismo!mimsy!chris ARPA/CSNet: chris@mimsy.umd.edu
chris@mimsy.UUCP (12/10/86)
In article <4685@mimsy.UUCP> I wrote: >We have DEC service on the [CDC] 9771s .... I was misled. We had *no* service contract. We just tried DEC on a per-call basis, but the local DEC service have never done CDC 9771s before, and declined to experiment on ours. Back to CDC.... -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690) UUCP: seismo!mimsy!chris ARPA/CSNet: chris@mimsy.umd.edu
jc@piaget.UUCP (John Cornelius) (12/11/86)
In article <4685@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes: ->>In article <4647@mimsy.UUCP> I mentioned ->>>... our source machine is down with broken CDC 9771 drives. -> ->In article <1306@cit-vax.Caltech.Edu> mangler@cit-vax.Caltech.Edu ->(System Mangler) writes: ->>More than one broken? -> ->Well, one for certain: -> .... ->We have DEC service on the 9771s, because another campus group had ->trouble with CDC service. Whether DEC know how to repair CDC drives ->remains to be seen, but it is unlikely they will be worse than CDC. I sold a 9771 to a good customer once. DEC took it under maintenance and when the HDA went it took DEC a month to figure out that they couldn't fix it. CDC then took another 2 months to fix it and I think they did it by replacing the drive. I had to loan the customer an Eagle so that he could run while DEC and CDC were tripping over their ties. DEC subsequently removed the 9771 from the maintenance contract and hasn't taken on any more that I know of. I probably would not sell a 9771 to anyone except DEC or CDC; I figure that they deserve each other's service organizations. I have had crashes on other manufacturer's drives as well and the differnce in service is astonishing. When I was selling Century drives they discovered a problem in the HDA and recalled all of the drives in the field that had the problem. They sent out new drives to swap out with the drives that had the problem BEFORE the old drives broke. Even though that meant more work for me it was a lot less work than having to have one of you guys pummel me about having a busted HDA and all the data that you lost. By the way, Century has a current product with 800 Megabytes of data and in the second quarter of next year will be delivering a 1 Gigabyte product. These are all 8" drives so in a 5' rack you can get about 10 Gigabytes. Access times are a quite respectable 16ms average and latency is the usual 8 ms or thereabouts. -- John Cornelius (...!sdcsvax!piaget!jc)