Re: [Xen-users] problem accessing swap partition on a xen machines

[Michael Gregg <mgregg@xxxxxxxxxxxxxxxx>]

ahh, the swap was in test during this test. 

There was a lot here for me to track down, but the problem ended up
being my goof. 

I have about 20 xen machines, and all could have the problem in higher
load situations. 

The problem ended up being my xen configuration files. 

I was listing my disks as so:
disk = ['phy:vg/dwm-dev_data,sda1,w' ,'phy:vg/dwm-dev_swap,sda2,2']
---------------------notice the "2"-----------------------------^

The 2 should have been w, like this:
disk = ['phy:vg/dwm-dev_data,sda1,w' ,'phy:vg/dwm-dev_swap,sda2,w']
---------------------now it's a "w"-----------------------------^

Anyhow, with the 2 there xen was starting up the disk in some unknown
mode that broke my swap space. 

Thanks for the reply.

Michael-

On Wed, 2005-11-02 at 08:56 +0100, Dirk H. Schulz wrote:
> Hi Gregg,
> 
> did you have a look if swap space is used during your dd run?
> 
> If it is not in use, then the question is, if the problem is restricted 
> to swap space? Did you test your other lvm (it's lvm, isn't it?) volumes 
> as well?
> 
> Dirk
> 
> Michael Gregg schrieb:
> 
> >I'm using debian stable with a recompiled xen dom0 kernel. 
> >
> >running debian on any domu.
> >
> >My partitions are drives created with lwm.
> >
> >I'm having problems with my swap partiton getting corrupted. When I get
> >the problem, if I pull the data from the swap with dd and get errors. If
> >I wait a few minutes, the problems go away.
> >
> >Has anybody seen this? Does anybody have any idea on howto solve this?
> >Please ask questions if you need more information.
> >
> >problem observed:
> >mg-gws:~# dd if=/dev/sda2 of=/dev/null
> >end_request: I/O error, dev sda2, sector 5080
> >end_request: I/O error, dev sda2, sector 5120
> >end_request: I/O error, dev sda2, sector 5208
> >end_request: I/O error, dev sda2, sector 5296
> >end_request: I/O error, dev sda2, sector 5384
> >end_request: I/O error, dev sda2, sector 5392
> >end_request: I/O error, dev sda2, sector 5424
> >end_request: I/O error, dev sda2, sector 5464
> >end_request: I/O error, dev sda2, sector 5552
> >end_request: I/O error, dev sda2, sector 5640
> >2097152+0 records in
> >2097152+0 records out
> >1073741824 bytes transferred in 10.769949 seconds (99697949 bytes/sec)
> >
> >1 minute after problem. 
> >mg-gws:~# dd if=/dev/sda2 of=/dev/null
> >2097152+0 records in
> >2097152+0 records out
> >1073741824 bytes transferred in 10.769949 seconds (99697949 bytes/sec)
> >
> >My xen config is as follows:
> >
> ># Creator: michael gregg
> ># Creation Date: Wed Oct 26 11:51:54 PDT 2005
> ># contact email: mgregg -at- propel.com
> ># created with: CreateXenVm mg-gws 192 michael gregg
> >#
> >vif  = ['mac=42:42:00:80:01:92']
> >interface = "eth0"
> >memory = 128
> >name = "mg-gws"
> >kernel = "/boot/xen-linux-2.6.11-ocxenu"
> >disk = ['phy:vg/mg-gws_data,sda1,w' ,'phy:vg/mg-gws_swap,sda2,2']
> >root = "/dev/sda1"
> ># assigned IP Address: 172.16.80.192
> >
> >
> >_______________________________________________
> >Xen-users mailing list
> >Xen-users@xxxxxxxxxxxxxxxxxxx
> >http://lists.xensource.com/xen-users
> >  
> >

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