friedl@mtndew.UUCP (Stephen J. Friedl) (07/21/90)
Hi folks,
I don't get this group [yet] so forgive me if I'm jumping in
the middle of a flamefest or anything. We are porting our fax
software to lots of different machines, and NCR has generously
loaned us a Tower 32/650 to do it on. We have tapes for System V
Releases 2 *and* 3, and we have calls for software running on
both.
Is it possible to load both versions of the OS onto the hard
drive and boot one or the other easily? If we have to reload
from tape every time we need the other one it will clearly drive
me crazy.
I suppose we could do it with a pair of drives and just boot
off the appropriate one, but I'd like to try to do this off of
one internal drive (a 300MB Maxtor SCSI drive). I have
partitioned the drive into a pair of 150MB partitions (numberred
1 and 2) and loaded Sys V Rel 2 onto the first one.
I have hunted around for where the partition tables are located,
and while I have an idea on this, I don't know how to mark a partition
as having containing the root filesystem -- perhaps it's always the
first one. If I hacked around at this for hours and hours I could
probably figure it out, but that is a very long road to go down for
what is not our primary platform.
Can anybody help? Please respond via email...
Steve
--
Stephen J. Friedl, KA8CMY / Software Consultant / Tustin, CA / 3B2-kind-of-guy
+1 714 544 6561 / friedl@mtndew.Tustin.CA.US / {uunet,attmail}!mtndew!friedl
I hope I get to invent as many useless languages as Nicklaus Wirth has.tedmonds@convex.com (Tracy Edmonds) (07/23/90)
In article <467@mtndew.UUCP> friedl@mtndew.UUCP (Stephen J. Friedl) writes: >Hi folks, > > I don't get this group [yet] so forgive me if I'm jumping in >the middle of a flamefest or anything. We are porting our fax >software to lots of different machines, and NCR has generously >loaned us a Tower 32/650 to do it on. We have tapes for System V >Releases 2 *and* 3, and we have calls for software running on >both. > > Is it possible to load both versions of the OS onto the hard >drive and boot one or the other easily? If we have to reload >from tape every time we need the other one it will clearly drive >me crazy. > No. There is only one rootable/bootable file system per disk. However, There are some possible other options: 1) I believe it is possible to boot the V.3 kernel on a V.2 root file system (this may also require both versions of /etc/init). 2) If your release specific calls are not related to the kernel then you can place an alternative root file system in a subdirectory and simply do a chroot. > I suppose we could do it with a pair of drives and just boot >off the appropriate one, but I'd like to try to do this off of >one internal drive (a 300MB Maxtor SCSI drive). I have >partitioned the drive into a pair of 150MB partitions (numberred >1 and 2) and loaded Sys V Rel 2 onto the first one. This would be the best way to do it. In this case you simply make kernels for each with the rootdev swapdev etc. set appropriately and then set the manual auto switch on the top of the unit to manual. When booting up through SUS you simply specify "h501 or h502". > > I have hunted around for where the partition tables are located, >and while I have an idea on this, I don't know how to mark a partition >as having containing the root filesystem -- perhaps it's always the >first one. If I hacked around at this for hours and hours I could >probably figure it out, but that is a very long road to go down for >what is not our primary platform. Just use the dkpart command to browse at the partition tables and/or change them. Read the man page first. Also these functions can be performed nicely through VA. -tracy Tracy Edmonds Convex Computer Corporation tedmonds@convex.com (214) 497-4753
wescott@Columbia.NCR.COM (Mike Wescott) (07/24/90)
In article <467@mtndew.UUCP> friedl@mtndew.UUCP (Stephen J. Friedl) writes: > Is it possible to load both versions of the OS onto the hard > drive and boot one or the other easily? Yes. > I suppose we could do it with a pair of drives and just boot > off the appropriate one, The easiest and most obvious way but not necessarily the most efficient use of resources ... > but I'd like to try to do this off of > one internal drive (a 300MB Maxtor SCSI drive). I have > partitioned the drive into a pair of 150MB partitions (numberred > 1 and 2) and loaded Sys V Rel 2 onto the first one. A good start. What you need to do is make a filesystem on the second partition and copy everything to it. Then remake /unix so that the rootdev is also partition 2, save this on the second partition. Now install SysVr3 release onto the first partition. When done mount the second partition read only and copy the second partition's unix to /unix.r2 and unmount. Link /unix to /unix.r3. Then boot either /unix.r2 or /unix.r3. If you remake the r2 kernel remember to copy it down to the first partition (you may have to boot the r3 kernel to do this). AN ALTERNATE METHOD: It possible to tell the boot program the start address of the partition in which it will find the kernel. With this in mind we can put the r2 root filesystem and kernel (with rootdev spec'd as partition 2) on the second partition and leave the r3 system on partition 1. You then boot in manual mode and tell SUS to boot from "/unix" if you want to use partition 1 and tell SUS "/unix of312200" if you want to use partition 2 (assuming that partition 2 starts at block offset 312200). Some older Towers use a different syntax, "/unix;312200" I think. -- -Mike Wescott mike.wescott@ncrcae.Columbia.NCR.COM