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] Xen + Storage

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] Xen + Storage
From: Tom Fritz <tfritz@xxxxxxxxx>
Date: Mon, 12 Sep 2011 20:00:01 -0500 (CDT)
Delivery-date: Mon, 12 Sep 2011 18:01:29 -0700
Dkim-signature: v=1; a=rsa-sha256; c=simple/simple; d=novia.net; s=mail; t=1315875608; bh=AKYe0pMpuMlArEqfbMZYW7qXAIK0tegZaXcMnLxA6P4=; h=Date:From:To:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=Ntp4ibG7vS3ftJTBLWPHzpeVpuX/ntIzuMFzhgmCPHS7FkmBOI2Z7bEIM8boJoyzW dtgZ6I4OtrSLLcn4VoH7xfSSM8fdCmgQ6nwZodV52/t7/j8rUEsIQw55HlB3ngcl+A ZtZ3+xckq3GNZiCURGBgeBVd8tKpClM9Bwc+emow=
Domainkey-signature: a=rsa-sha1; s=mail; d=novia.net; c=nofws; q=dns; h=received:x-authentication-warning:date:from:to:subject: in-reply-to:message-id:references:organization:mime-version:content-type; b=tfbBlAfolcH5YRo7HY8FpiL4PLWMM6Wv7zwCxUV+9uitkSudJXtk0cgAvE5B1aih1 hlkz3MOfSPMNa62HXAPozTtLo2s6lj3Qt4wG7v/5wXiAGtZ4hfh2JO2zVp3DIoFdtQB 4BEp/jPNnnU/d0IEYQNwHkvLmhXDEFrBV2iR7fI=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4E6E9F9A.7010809@xxxxxxxxx>
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/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
Organization: Novia Internetworking
References: <4E6E9F9A.7010809@xxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx

i have 4 debian squeeze with xen 4 and all them with 4 to 6 HVM virtual machines. All the VMs are located in a fith machine (A SuperMicro LSI Controller as storage). The host servers are Intel i7 with 24GB fo RAM (Debian Squeeze + Xen4) and the storage a Xen 3.0 with 8GB of RAM (CentOS 5.5 + TGTD) and thery are all connect with a gigabit network dedicated for the iSCSI. My problem is, when working at the storage, doing backup procedures with the command dd and using the bzip2, the IOWait increases a litle bit, the normal state is close to 0%, but when copying or moving the files generated by the backup, usually bigger than 2G, the IOWait increases too much, reaching 100%, in cases in all 4 cores, making the virtual machines stop responding and even if i stop the procedure, the virtual machines doesnt comes back, been necessary a reboot or shutdown. Does anyone knows about this problem ? And there is any configuration that i could do in the iSCSI-Target and Initiator to increase de performance? And a configuration in the virtual machines filesystem to prevent it from stopping?


I always use ionice when using dd to do a backup. You should also look into scst-iscsi. The default for most distro's is the IET iscsi.

Cheers,

Tom.

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