aoki@faerie.Berkeley.EDU (Paul M. Aoki) (01/07/89)
That's right, M23*7*2, not M23*8*2 (Swallow 5). I am given to understand that these beasts are running fine on somebody's Symmetry somewhere (Sequent doesn't support them). Unfortunately, the helpful, nice people who gave me to understand this were *not* the people whose bid was lowest (praise be to University Purchasing, who saved us money and cost us decent support). When you don't buy from people they tend to be less helpful and nice, so now we have two M2372 disks but no formatting info. [ No flames, please, that's not the whole story. ] As far as the /etc/disktab entry goes, I can figure out everything except "ns". Following the wonderful instructions in the Fujitsu manual I get ns#80. That's fine with me, but the Swallow 5 entry is ns#81, and ns * nt * nc+3 * 512 = 81 * 27 * 748 * 512 = 838MB which is not the size of a Swallow 5. So the Sequent folks did something funny -- they aren't using all of the disk. On the other had, the M2351 entry is what you would expect, so now I don't know what to believe. Anyone out there have a working disktab entry (plus any random driver hacks, if any) for a M2372 on a ZD controller? ---------------- Paul M. Aoki CS Division, Dept. of EECS // UCB // Berkeley, CA 94720 (415) 642-1863 aoki@postgres.Berkeley.EDU ...!ucbvax!aoki
stan@hydra.gatech.EDU (Stan Corbin) (01/07/89)
In article <8614@pasteur.Berkeley.EDU> aoki@postgres.Berkeley.EDU (Paul M. Aoki) writes: >As far as the /etc/disktab entry goes, I can figure out everything >except "ns". Following the wonderful instructions in the Fujitsu >manual I get ns#80. That's fine with me, but the Swallow 5 entry is >ns#81, and > > ns * nt * nc+3 * 512 = 81 * 27 * 748 * 512 = 838MB > >which is not the size of a Swallow 5. So the Sequent folks did >something funny -- they aren't using all of the disk. I believe that zdformat uses one "spare" sector at the end of each track for remapping bad sectors. Therefore, the number for ns in /etc/disktab should be one less than the actual number of sectors per track that the drive has. In other words, when computing the capacity of the drive, you should use ns+1 (just like you used nc+3). Also, if you are trying to compute the total unformated capacity, you should used the actual sector size including headers (I think usually around 600 - 650) rather than 512. -- Stan Corbin stan@prism.gatech.edu Office of Computing Services ...!gatech!prism!stan Georgia Institute of Technology Atlanta, Georgia 30332-0275