ridout@uservx.afwl.af.mil (03/23/91)
Hi all, I know this was discussed a long time ago, byt at the time I didn't think I had the need. So here is my problem. I want to put ultrix on one of the VAXes in my VMS CI cluster. I could just pull the machine off the cluster hook up some drives and away I go. But I need tape drives. I have some third party STC drives from SI but they require a driver patch so I cannot use them as the install device. So my question is: Can I have my VMS vax and Ultrix VAX connected to the same star and use the same HSC to share the tape drives? And to extend the question a bit further, can the disks remain on the HSC i.e. some of the disks on the HSC belong to the VMS machine and some of the disks belong to the Ultrix machine. I can live with the disks being removed from the HSC but I really need a tape drive for doing the installs. -- **************************************************************************** * Brian Ridout What's the difference between a CAR * * PL/SCEV salesman and a COMPUTER salesman? * * Kirtland AFB NM 87117 * * * ridout@uservx.afwl.af.mil The CAR salesman KNOWS when he's lying! * ****************************************************************************
alan@shodha.enet.dec.com ( Alan's Home for Wayward Notes File.) (03/23/91)
In article <1991Mar22.154344.21227@uservx.afwl.af.mil>, ridout@uservx.afwl.af.mil writes: > So my question is: Can I have my VMS vax and Ultrix VAX connected to the same > star and use the same HSC to share the tape drives? Probably, but it's not a supported configuration. Most examples I've heard of work without much trouble. Sharing just the tape drives is probably the safest way to go. > And to extend the question a bit further, can the disks remain on the > HSC i.e. some of the disks on the HSC belong to the VMS machine and > some of the disks belong to the Ultrix machine. You could do it this way. But, have you heard of the evils of a partitioned cluster. One where multiple uncooperating system are accessing the same disk and slowly trashing the contents. An ULTRIX and VMS sharing the same HSC is a fine example of one of these about to happen. All it takes is an operator accidently doing an INIT/ERASE on the ULTRIX user disk, or on the ULTRIX system someone doing an newfs(8) on the VMS system disk. There are tricks you can do to reduce the chance of something like happening. On the ULTRIX side you just take the VMS disks out of the configuration file. From the VMS you might be set the device NOAVAILABLE (or whatever it is). If you only one system accessing a disk you can set it exclusive access for that host from the HSC. You'll have to redo this part if the HSC reboots. If you can put the disks that the ULTRIX system on local disk controllers this is best. Then as money permits get a 2nd Star Coupler and HSC for the ULTRIX system. Another possibility if you have a VAX 6000 (or VAX 9000) as the ULTRIX system is to get a CIXCD and connect the tapes to it. If the tape are dual ported you'll have to give this up, though. > -- > * Brian Ridout What's the difference between a CAR * -- Alan Rollow alan@nabeth.cxn.dec.com