Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!bionet!ames!attctc!cbradley
From: cbradley@attctc.Dallas.TX.US (Chris Bradley)
Newsgroups: comp.sys.next
Subject: Re: 40BM accelerator and setuid problems
Summary: Getting a swapdisk running
Keywords: swapdisk 40 40mb
Message-ID: <10841@attctc.Dallas.TX.US>
Date: 6 Jan 90 00:01:18 GMT
References: <9494@batcomputer.tn.cornell.edu>
Reply-To: cbradley@blackbox.UUCP (Chris Bradley)
Followup-To: comp.sys.next
Distribution: usa
Organization: Businessland Advanced Systems
Lines: 36

In article <9494@batcomputer.tn.cornell.edu> rogerj@tcgould.tn.cornell.edu (Roger Jagoda) writes:
>Another related question about these drives. The OS seems 
>smart enough to symbolically link /tmp to the newly installed
>accelerator drive, however, the swapfile, /private/vm/swapfile
>still lives where it did BEFORE installation (in our case on
>our network server since the client machines are diskless). Is     
>an error of omission? Wouldn't I want to link the swapfile to grow
>on the swap/accelerator disk?
> 

I was looking at this, too, when the topic of swapdisks came up the other
day.  It's discussed (briefly!) in the on-line doc ("Appendix A: System
Initialization" [/NextLibrary/Documentation/NeXT/SysAdmin/ApA_BootSequence.wn])
and describes the action of the /etc/rc.swap file.

Basically, /etc/rc calls /etc/rc.swap, which is supposed to determine
if you have a suitable swapdisk.  In /etc/rc.swap, there is this shell
fragment:

	# Find out which device to check
	SWAPDEV=`grep /private/swapdisk /etc/fstab | awk '{print $1}'\
		| sed -e 's/\/dev\///'`

which looks like it does indeed examine /etc/fstab for a swapdisk device.

After that, the program /usr/etc/checkswap is run (checkswap(8)) to see if 
the disk label on the purported swapdisk is indeed ``swapdisk''.

There's a little more to it, but I don't wanna transcribe the manual thru
the net's bandwidth.

-- 
Chris Bradley               |  "To integrate Advanced Technologies into new |
Sr. Eng'r, Advanced Systems |  and existing customer environments."         |
Businessland, Inc.          |- - - - - - - - - - - - - - - - - - - - - - - -|
Dallas, Texas USA           |  Known to management, but unclaimed thereby   |