[comp.os.minix] Second RAM disk?

u27602@uy.ncsa.uiuc.edu (Jeffrey C. Ollie) (03/15/91)

Hello *,

  I am wondering if it is possible to create a second ram disk (approx.
300k in size) and then mount it on /tmp.  This would speed up a lot of
operations (including patch, which takes up a lot of disk space).

  Has anyone tried this, or would like to try this, and report the results
back to the group?

Jeff

Internet: u27602@uy.ncsa.uiuc.edu

HBO043%DJUKFA11.BITNET@cunyvm.cuny.edu (Christoph van Wuellen) (03/16/91)

Why do you need a second RAMdisk?

I always have a root file system of 1.5 MB, and /tmp simply is in the root
file system. This serves all my needs.

C.v.W.

gert@targon.UUCP (Gert Kanis) (03/22/91)

In article <47610@nigel.ee.udel.edu> u27602@uy (Jeffrey C. Ollie) writes:
>Hello *,
>
>  I am wondering if it is possible to create a second ram disk (approx.
>300k in size) and then mount it on /tmp.
>
>Jeff

The question is: `What do you do with the RAM disk that you have ?'

If you have your root fs in it (like the default situation) then /tmp
(and /bin for that matter) is allready in the RAM disk unless you
mount a hd partition or floppy on it.

If you happen to run your system with the root fs on a (hard) disk partition
then you have still the possibility the use the (one and only :-) ram disk
for /tmp.
The latter requiers to change some defines in boot.h, recompile the kernel
and some line in /etc/rc that create a valid file system (mkfs) in /dev/ram.
(maybe also a mknod of /dev/ram with a size parameter).

Still want a 2nd RAM disk ?

Gert Kanis.
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kjh@pollux.usc.edu (Kenneth J. Hendrickson) (03/24/91)

In article <1690@targon.UUCP> gert@targon.UUCP (Gert Kanis) writes:
>If you happen to run your system with the root fs on a (hard) disk partition
>then you have still the possibility the use the (one and only :-) ram disk
>for /tmp.
>The latter requiers to change some defines in boot.h, recompile the kernel
>and some line in /etc/rc that create a valid file system (mkfs) in /dev/ram.

I just recently started using a hard disk partition as the root file
system, (because I didn't want to have to manually mount the image, and
copy files every time I edited them), and I never changed any constants
anyplace.  Am I courting disaster?

--

I have thought of a good use for more than 1 ram disk.
mounted on /tmp for obvious reasons.
mounted on /bin to have fast access to commonly used commands.
mounted on /usr/bin to have fast access to all other commands.

--

The above may significantly improve the speed of Minix, as perceived by
the user.

I haven't yet looked at the source code (shame on me), but would there
be much more involved than creating all the /dev/ramX entries you
wanted, with different minor device numbers, and specifying the maximum
of all /dev/ramX entries at boot up time?  Perhaps just a minor
modification to the ram disk device driver?

-- 
favourite oxymorons:   student athlete, military justice, mercy killing
Ken Hendrickson N8DGN/6       kjh@usc.edu      ...!uunet!usc!pollux!kjh