Re: [Xen-devel] RAM allocation and miscellaneous questions - Mat - com.xensource.lists.xen-devel

15 messages in com.xensource.lists.xen-develRe: [Xen-devel] RAM allocation and mi...

From	Sent On	Attachments
Paul Dorman	28 Sep 2004 19:57
Mark A. Williamson	28 Sep 2004 20:30
Paul Dorman	28 Sep 2004 21:56
Ian Pratt	29 Sep 2004 00:55
Keir Fraser	29 Sep 2004 01:37
Mat	29 Sep 2004 04:12
Mark A. Williamson	29 Sep 2004 05:25
Paul Dorman	29 Sep 2004 12:15
Ronald G. Minnich	29 Sep 2004 12:53
Ian Pratt	30 Sep 2004 01:25
Keir Fraser	30 Sep 2004 02:02
Mark A. Williamson	30 Sep 2004 06:25
Brian Wolfe	30 Sep 2004 13:21
Mark A. Williamson	30 Sep 2004 13:23
Mike Brady	01 Oct 2004 14:19

Subject:	Re: [Xen-devel] RAM allocation and miscellaneous questions
From:	Mat (ma...@matws.net)
Date:	09/29/2004 04:12:07 AM
List:	com.xensource.lists.xen-devel

On September 29, 9:55 am Ian Pratt <Ian....@cl.cam.ac.uk> wrote:

It certainly does Mark (help, that is). I would like to learn more about this balloon driver, which could make things very managable. Is there any documentation or tutorial-like info about?

The balloon driver hasn't been forward ported from 2.4 to 2.6 -- it's on the todo list (it'll probably work unmodified modulo changes to the way proc fs works).

For people that still use linux 2.4 (like me) is there a tutorial or some documentation about the ballon driver ?

I have been wondering why my Domain-0 machine hasn't been using swap! :o) So I should just dump that partition?

If you've configured swap, domain 0 should be using just like any normal linux kernel. The balloon driver works in dom0 just like any other domain.

It seems logical, but due to the fact that only a few process are running ind dom0, swap file don't need to be huge is it ?

I suppose I'll have to be very rigorous when it comes to keeping that domain lean yes? (Especially as I only have 4GB to play with!). Out side of basic OS functionality, are there any Xen or LVM2 related processes I have to account for when setting the amount of RAM I can use for Domain-0?

-xen linux kernels don't have any special processes that take any noticeable extra resources.

In domain 0 you'll have to worry about the footprint of xend, but it's not that big.

When starting with xen one or two month ago, i've created a dom0 with only 32 Mo of ram, and when i launched xend, it was so slow that i tought i had a problem. I didn't take time to investigate and didn't remember how much memory was used and if the system was swaping or not. I just have done a test now with my current xen putting 32768 Mo on xen command line (not the kernel line in grub). And the system booted a bit slower and i suspect that durring the launch of xend it has done some swap. free return this just after the boot : mat@zeus:/$ free total used free shared buffers cached Mem: 32768 28572 4196 0 0 7172 -/+ buffers/cache: 21400 11368 Swap: 506008 312 505696

Having this process: 207 ? Ss 0:00 dhclient -e -pf /var/run/dhclient.eth0.pid -lf /var/ 253 ? Ss 0:00 /sbin/syslogd 256 ? Ss 0:00 /sbin/klogd 261 ? Ss 0:00 /usr/sbin/inetd 268 ? Ss 0:00 /usr/sbin/sshd 274 ? S 0:00 xfrd 275 ? S 0:00 python /usr/sbin/xend start 288 ? Ss 0:00 /usr/sbin/cron 327 tty1 Ss+ 0:00 /sbin/getty 38400 tty1 328 tty2 Ss+ 0:00 /sbin/getty 38400 tty2 329 tty3 Ss+ 0:00 /sbin/getty 38400 tty3 330 tty4 Ss+ 0:00 /sbin/getty 38400 tty4 331 tty5 Ss+ 0:00 /sbin/getty 38400 tty5 332 tty6 Ss+ 0:00 /sbin/getty 38400 tty6 333 ? Ss 0:00 sshd: mat [priv] 335 ? R 0:00 sshd: mat@pts/0 336 pts/0 Ss 0:00 -bash 344 pts/0 R+ 0:00 ps ax

i guess i could reduce the number of getty and get rid of dhclient (the adress of dom0 is a static one ...).

It was my 2cents thoughts ... Matthieu