Re: [Xen-devel] RAM allocation and miscellaneous questions

["Mat" <mat@xxxxxxxxx>]

On September 29, 9:55 am Ian Pratt <Ian.Pratt@xxxxxxxxxxxx> 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


-------------------------------------------------------
This SF.net email is sponsored by: IT Product Guide on ITManagersJournal
Use IT products in your business? Tell us what you think of them. Give us
Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more
http://productguide.itmanagersjournal.com/guidepromo.tmpl
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/xen-devel