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From: andyw@aspen32.cray.com (Andy Warner)
Newsgroups: comp.sys.3b1
Subject: Re: swap space
Message-ID: <100425.7286@timbuk.cray.com>
Date: 13 Jun 91 18:40:59 GMT
Article-I.D.: timbuk.100425.7286
References: <1991Jun9.170520.4087@yenta.alb.nm.us> <1991Jun11.030216.6155@ceilidh.beartrack.com>
Organization: Cray Research, Inc.
Lines: 39


In article <1991Jun11.030216.6155@ceilidh.beartrack.com>, dnichols@ceilidh.beartrack.com (DoN Nichols) writes:
> In article <1991Jun9.170520.4087@yenta.alb.nm.us> dt@yenta.alb.nm.us (David B. Thomas) writes:
> >How does the 3b1 know where to find swap space, and can it use the "swap
> >partition" on the second hard disk?
> >
> >						little david
> 
> 	It looks for the special device file "/dev/swap".  Here, we see that
> it is the same major and minor device numbers as /dev/fp001, and probably
> should be linked, but isn't on this system.  If you do so, you should use
> the permissions and ownership of the "swap" listing.
> 
> br--------  1 root    root      0,  1 Dec 30 21:42 /dev/fp001
> brw-r-----  1 sys     sys       0,  1 Dec 30 21:50 /dev/swap
> 
> 	You should be able to simply replace "/dev/swap" with a link to the
> selected partition on your other drive, but I know of no way to have it use
> .....

This probably won't work. I'll defer to anyone with access to the
source, but the kernel doesn't use /dev/swap, that's just for things like
ps. Most V.2 kernels use three variables rootdev, swapdev & pipedev to
find their root, swap & pipe device. These are either compiled into the
binary (though they are variables, so you can patch them with adb), or
are picked up from the Volume Header Block of the boot disk. I don't
know if the Convergent VHB hold information about what a slice is to
be used for (I've got a feeling it doesn't). One good thing is that
I'm sure they pick up the size of the swap device from the VHB, so you
don't have to tweak that.

So you can do it, but you'll need to patch swapdev, and then ALSO
change /dev/swap.

Hope this helps,
--
andyw.	(W0/G1XRL)

andyw@aspen.cray.com	Andy Warner, Cray Research, Inc.	(612) 683-5835