WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] heavy write crashing, was: process limit

To: Tim Freeman <tfreeman@xxxxxxxxxxx>
Subject: Re: [Xen-users] heavy write crashing, was: process limit
From: Anand <xen.mails@xxxxxxxxx>
Date: Sat, 14 Jan 2006 03:01:13 +0530
Cc: xen-users@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 13 Jan 2006 21:38:11 +0000
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=XHttMVjEwCX9/FZjz8uswIlCe75r+iQ9X8uSm+3dsX/0o4KWU7dSZ8Xvts1tRqEby4TpMt0gS3uUDq4b1alh6kzRzkJkGo2TmgsBDy6tRZ/hgBhLTcZrfa/Y3/avxQuhg0pQqtPunEb4IdVLOJmNt5zv7sAMNldjS0ROPLuxNCw=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20060111204116.2fa270a9.tfreeman@xxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <20060111204116.2fa270a9.tfreeman@xxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
On 1/12/06, Tim Freeman <tfreeman@xxxxxxxxxxx> wrote:
You can experience some nasty hangs with Xen 3.0.0 when running certain stress
invocations in domU, particularly with the --hdd option: "spawn N workers
spinning on write()/unlink()" (default is 1GB write()).

This is just some casual experience:

In a loopback mounted domU, I ran "stress -v --hdd 1" and it will almost
immediately kill the machine.

I increased dom0's RAM to try and help dom0's kernel with the writing and after
giving dom0 a whole gigabyte, it lasted longer but still locks up.

I gave dom0 much more CPU (almost half), kept its high RAM allocation, and it
did a lot better in this situation, lasted a lot longer, but eventually the
system became unresponsive.  Here, console toggling from the keyboard of the
real machine still worked up until the time my patience ran out...


So my guess wasn't wrong after all, a process which tries to do heavy IO even with cpu scheduling could cause the entire machine to go down. This could be prevented if we could somehow do disk io management between the domains.

--

regards,

Anand
_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users