On 10/05/2017 09:39 PM, Jerry Weiss via cctalk wrote: > The DK Driver for VMS versions around 5.x definitely had a problem with > non-DEC disks. 6.X and greater were slightly more forgiving.
Having many of the era DEC VAX I can say the only SCSI issue I had was the boot disk greater than 1.07 GB. for second or third disks that was not an issue. It was a system diagnostic/boot rom issue. I've used most anything I could find that was SCSI or SCSI-2. Most were Seagate or WD, and a few with Compaq/fujitsu labels. With VMS 5, but not 5.0. Allison > The specifics are summarized in a note from Ralph Weber in > https://groups.google.com/forum/#!search/SCSI$20Mode$20Page$20Requirements$20$20axp/comp.os.vms/RAaUpP_XXEw/BWn64YZYwBQJ > . > > I don’t think there is list of non-DEC disks in the driver as it instead > checked the SCSI Mode bits and other disk configuration settings. There is > a list (table) for DEC Drives (idiosyncrasies?) and another SCSI2 Tagged > Queuing devices requirements used for Clusters in the driver. > > Regards, > Jerry > > > >> On Oct 5, 2017, at 6:23 PM, Peter Coghlan via cctalk <cctalk@classiccmp.org> >> wrote: >> >> >> >>> The biggest problem you had was the requirement to assert ATN when selected >>> properly.� Later the tag queuing caused huge headaches as manufacturers >>> implemented that feature. >>> >>> It eventually was made mandatory for the most part by linux, and perhaps >>> Windows requiring the tag queuing drilled own to the lowest level of the >>> system's use of the disk. The capability to do that, or fake it is >>> required to allow the kernel to queue commands to run, and have the OS >>> continue to run till command completion. >>> >> I recall VMS having issues with SCSI disks which claimed to do tag queueing >> (and bad block replacement) but didn't do it right, before I'd even heard >> of linux. >> >> Customers complained that VMS refused to work with commodity SCSI disks >> and thought that it was a conspiracy to get them to buy expensive DEC branded >> disks. DEC claimed that only the disks with their firmware did tag queueing >> and bad block replacement correctly. The VMS SCSI driver supposedly had >> (has?) >> a list of specific disks known to mess up which it would refuse to bring >> online. >> >> I wasn't well up on Sun but I expect the same issue existed there too. >> >> Regards, >> Peter Coghlan. > >
