wcs@ho95e.ATT.COM (Bill.Stewart) (12/10/87)
We have a couple of VAXen that need decent disk drives (They've currently got RA81s, which crash weekly.) We're looking for about 1-2 GB for less than $40K. I'd be interested in anything, but have a slight preference for SCSI, since we'll be able to reuse that with other systems when we retire the VAXen. We can do either Unibus or Massbus drives. So what's out there? I'm interested in comments from both technical people and sales people. -- # Thanks; # Bill Stewart, AT&T Bell Labs 2G218, Holmdel NJ 1-201-949-0705 ihnp4!ho95c!wcs
rob@philabs.Philips.Com (Rob Robertson) (12/11/87)
In article <1917@ho95e.ATT.COM> wcs@ho95e.ATT.COM (Bill.Stewart) writes: >We have a couple of VAXen that need decent disk drives. >So what's out there? I'm interested in comments from both technical people and >sales people. we have some Systems Industries 9751 (eagle) and 9761 (double eagle), the single eagle drives are pretty good, but the double eagles are a constant source of problems, both had their hard disk assemblies replaced, spent yesterday doing that. The SI Field Engineer tells me that the lasest rev of the drive is much more reliable than the earlier ones---guess i'll wait and find out. also, checkout how your vendor will support the drives under unix. our site is the only Unix Vax our FE supports, so he knows diddly about the system ('gee didn't know unix cared about the order of the bad blocks'). rob -- william robertson rob@philabs.philips.com
seb022@tijc02.UUCP (Scott Bemis ) (12/16/87)
> We have a couple of VAXen that need decent disk drives (They've currently got > RA81s, which crash weekly.) We're looking for about 1-2 GB for less than $40K. > I'd be interested in anything, but have a slight preference for SCSI, since > we'll be able to reuse that with other systems when we retire the VAXen. > We can do either Unibus or Massbus drives. > > So what's out there? I'm interested in comments from both technical people and > sales people. > -- > # Thanks; > # Bill Stewart, AT&T Bell Labs 2G218, Holmdel NJ 1-201-949-0705 ihnp4!ho95c!wcs You may also contact another person at your company, Andrew Wild, Telephone (201) 582-5810, he could offer you his advice on the CDC 9773 disk drives. I hope he does not mind his name being posted on Usenet. How about investigating CDC 9772 (700 MB formatted) or CDC 9773 (1.2 GB formatted?) disk drives along with the Emulex SC7003 disk controller. I currently am using two CDC 9772 disk drives on a VAX 8600. This VAX 8600 is using the AT&T UNIX V Release 2.0 Version 2 operating system. Carefully controlled bench- marks showed these disk drives to be 43 percent faster than the RA81 disk drives. Or other words, an extremely large make (compilation if you are not familar with UNIX) took 5 hours 41 minutes using a RA81 disk drive to store the data. When the data was stored upon the CDC 9772 disk drive, this exact (yes exact) same make took 3 hours 12 minutes. The only difference was the disk drive and disk controller. These benchmarks were used to determine if my company was going to buy the CDC 9772 disk drives (which is why they were carefully controlled). I have not had any problems with these disk drives, once they were properly installed and had passed diagnostics. I did receive one CDC 9772 disk drive that did not work. After spending one week on the Emulex hotline, I finally convinced them that it did not work. They sent me a replacement disk within 24 hours. Convincing them was the hard part. And the Emulex technician did not install the Emulex SC7003 disk controller correct the first time. DEC Field Service solved the problem. (Unfortunately, this nonsense is too common for me). Below is an installation history I presented to my company management. Here is a brief history describing the installation of the Emulex SC7003 disk controller and the two CDC 9772 disk drives. 11/23/87 Scott Bemis Installation history of the Emulex SC7003 disk controller and two Control Data Corporation Model 9772 disk drives on the UNIX VAX 8600 5/30/87 Received quote on disk controller and disk drives 6/5 - 6/18/87 Contacted several customers references, received good 4 references 6/26/87 Ordered two CDC disk drives and one SC7003 disk controller, committed ship date from Emulex was 7/24 8/24 Received equipment from Emulex, VAX 8600 could not be taken down due to the TISTAR release 10/9 Installed two CDC disk drives and SC7003 disk controller, one disk drive did not work, power (AC/DC low) to the disk controller was incorrectly connected, disk controller would not work if power was turned off and on for the VAX 8600 10/16 DEC Field Service "rewired" the power (AC/DC low) per Emulex instructions, can turn power off and on for VAX 8600, and the disk controller will still work 10/23-10/26 Ran diagnostics to prove one CDC disk drive did not work 10/27 UNIX operating system can communicate with the CDC 9772 disk drives 10/29 Ran benchmarks on one good disk drive, CDC disk drive 43% faster than the Digital Equipment RA81 disk drives 10/30 Replaced one CDC 9772 disk drive 10/31 Moved data to the two CDC disk drives 11/15 One CDC 9772 disk drive began to lose data, moved all data off the failing CDC 9772 disk drive - this was the disk drive that was replaced on 10/30 11/16-11/17 Ran diagnostics per Emulex's instructions. Discovered cause of data loss on bad disk drive. The bad sector map file was destroyed. But can not determine how this file was destroyed - to prevent it from happening again. 11/23 Discovered that UNIX had overwritten the bad manufacture sector file. Fixed problem, put data back upon the disk drive If the above is not enough, then you can contact me. My telephone, mail address, etc. is listed below. Scott Bemis Telephone: (615) 461-2959 Texas Instruments P. O. Drawer 1255 M/S 3517 Johnson City, TN 37601 e-mail: mcnc!rti!tijc02!root
roy@phri.UUCP (Roy Smith) (12/18/87)
In article <181@tijc02.UUCP> seb022@tijc02.UUCP (Scott Bemis) writes: > I currently am using two CDC 9772 disk drives [...] Carefully controlled > benchmarks showed the these disk drives to be 43 percent faster than the > RA81 disk drives. The 9772's may indeed be a very good drive (I don't know, I've never seen one), but to claim that it is fast just because it beats the pants off an RA-81 is absurd. The RA-81's are slow by any modern standard. According to the manufacturer's specs, the RA-81 has a 28 ms average seek time (actually, they quote it as "average positioning rate", whatever that means). The Fuji 2351 Eagle, for example, quotes 18 ms. I only pick the 2351 because it is of about the same vintage as the RA-81, both being introduced about 3-4 years ago or so. The difference is that the Eagle is still considered a reasonable drive to buy (although clearly the last few years have given it some competition) while the RA-81 was old when it was introduced. You can also buy Eagles (and, I suspect, most SMD disks) for about half the price per Mbyte of an RA-81. To be fair, the RA-81 was a radical departure in disk subsystem design. A lot of the smarts that used to be in the kernel-resident driver are now in the controller. I don't know how much the Unix drivers take advantage of the ability of the controllers (such as the most common UDA-50) to optimize disk operations. I suspect very little. With smarter and smarter controllers (such as the HSC-[57]0), and drivers designed to take full advantage of the hardware the RA-81 (and RA-82) may indeed come into their own. I tend to doubt it however. -- Roy Smith, {allegra,cmcl2,philabs}!phri!roy System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016