Hi all, I need to deploy different RedHat servers with Cluster Suite under Xen (using Intel VT hardware for hosts). To accomplish this, I need to setup a virtual shared storage disk to serve for several nodes. Can Xen 3.0.2 support disk locking feature to deploy clusters (Load balancing and HA configs) as vmware products support? Is this feature supported by xen? And my last question: can I use virtual scsi disk to use as a shared storage? Many thanks. -- CL Martinez carlopmart {at} gmail {d0t} com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
<thomas.vonsteiger@bluewin.ch>
2006-Aug-20 20:34 UTC
AW: [Xen-users] Deploying redhat clusters under Xen 3.0.2
Hi, If you change in /etc/xen/scripts/block Line 105 and 116 from echo local to: echo ok then you have on all virtual storage''s concurrent access (shared disk possible). With this change you don''t have protection on virtual storage if a xen guest dry to access other xen guest''s running storage! In case of ext3, your filesystem can corrupt in this situation. thomas> -----Ursprüngliche Nachricht----- > Von: xen-users-bounces@lists.xensource.com [mailto:xen-users- > bounces@lists.xensource.com] Im Auftrag von carlopmart > Gesendet: Freitag, 18. August 2006 22:43 > An: xen-users@lists.xensource.com > Betreff: [Xen-users] Deploying redhat clusters under Xen 3.0.2 > > Hi all, > > I need to deploy different RedHat servers with Cluster Suite under Xen > (using Intel VT hardware for hosts). To accomplish this, I need to setup > a virtual shared storage disk to serve for several nodes. Can Xen 3.0.2 > support disk locking feature to deploy clusters (Load balancing and HA > configs) as vmware products support? Is this feature supported by xen? > And my last question: can I use virtual scsi disk to use as a shared > storage? > > Many thanks. > > > -- > CL Martinez > carlopmart {at} gmail {d0t} com > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.405 / Virus Database: 268.11.3/423 - Release Date: 18.08.2006_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Fri, 2006-08-18 at 22:42 +0200, carlopmart wrote:> Hi all, > > I need to deploy different RedHat servers with Cluster Suite under Xen > (using Intel VT hardware for hosts). To accomplish this, I need to setup > a virtual shared storage disk to serve for several nodes. Can Xen 3.0.2 > support disk locking feature to deploy clusters (Load balancing and HA > configs) as vmware products support? Is this feature supported by xen? > And my last question: can I use virtual scsi disk to use as a shared > storage? > > Many thanks. > >Some more information about your cluster would be helpful :) How many nics per node, and is one of those nics talking to a private gig-e network? We use xen to help manage or completely contain everything from open SSI to our own pound / lighty / drbd / heartbeat based concoctions and quite frankly I can''t see doing without Xen in the future when it comes to both ha / load balanced and hpc clusters. Have you looked at gfs? Cheers -Tim _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
carlopmart
2006-Aug-21 07:23 UTC
Re: [Xen-users] Deploying redhat clusters under Xen 3.0.2
Tim, more information: - I wneed to use GFS filesystem for this virtual storage. - I do not use heartbeat, I have to deploy this configuration with RedHat Cluster Suite. - Only one network interface per node using 100Mb private netowrk. Thomas, About this: If you change in /etc/xen/scripts/block Line 105 and 116 from echo ‘local’ to: echo ‘ok’. I have some questions: - can this change affects to all disks in the guest, included node disk?? - How can I setup virtual storage in config file, as a normal disk without any param?? - If I use GFS and two nodes writing at same time, can this virtual storage be corrupted?? Many thanks Tim Post wrote:> On Fri, 2006-08-18 at 22:42 +0200, carlopmart wrote: >> Hi all, >> >> I need to deploy different RedHat servers with Cluster Suite under Xen >> (using Intel VT hardware for hosts). To accomplish this, I need to setup >> a virtual shared storage disk to serve for several nodes. Can Xen 3.0.2 >> support disk locking feature to deploy clusters (Load balancing and HA >> configs) as vmware products support? Is this feature supported by xen? >> And my last question: can I use virtual scsi disk to use as a shared >> storage? >> >> Many thanks. >> >> > > Some more information about your cluster would be helpful :) How many > nics per node, and is one of those nics talking to a private gig-e > network? > > We use xen to help manage or completely contain everything from open SSI > to our own pound / lighty / drbd / heartbeat based concoctions and quite > frankly I can''t see doing without Xen in the future when it comes to > both ha / load balanced and hpc clusters. > > Have you looked at gfs? > > Cheers > -Tim > > >-- CL Martinez carlopmart {at} gmail {d0t} com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
carlopmart
2006-Aug-21 07:31 UTC
Re: [Xen-users] Deploying redhat clusters under Xen 3.0.2
Tim, more information: - I wneed to use GFS filesystem for this virtual storage. - I do not use heartbeat, I have to deploy this configuration with RedHat Cluster Suite. - Only one network interface per node using 100Mb private netowrk. Thomas, About this: If you change in /etc/xen/scripts/block Line 105 and 116 from echo ‘local’ to: echo ‘ok’. I have some questions: - can this change affects to all disks in the guest, included node disk?? - How can I setup virtual storage in config file, as a normal disk without any param?? - If I use GFS and two nodes writing at same time, can this virtual storage be corrupted?? Many thanks> > > > Tim Post wrote: >> On Fri, 2006-08-18 at 22:42 +0200, carlopmart wrote: >>> Hi all, >>> >>> I need to deploy different RedHat servers with Cluster Suite under >>> Xen (using Intel VT hardware for hosts). To accomplish this, I need >>> to setup a virtual shared storage disk to serve for several nodes. >>> Can Xen 3.0.2 support disk locking feature to deploy clusters (Load >>> balancing and HA configs) as vmware products support? Is this feature >>> supported by xen? And my last question: can I use virtual scsi disk >>> to use as a shared storage? >>> >>> Many thanks. >>> >>> >> >> Some more information about your cluster would be helpful :) How many >> nics per node, and is one of those nics talking to a private gig-e >> network? >> >> We use xen to help manage or completely contain everything from open SSI >> to our own pound / lighty / drbd / heartbeat based concoctions and quite >> frankly I can''t see doing without Xen in the future when it comes to >> both ha / load balanced and hpc clusters. >> >> Have you looked at gfs? >> Cheers >> -Tim >> >> >> >-- CL Martinez carlopmart {at} gmail {d0t} com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
<thomas.vonsteiger@bluewin.ch>
2006-Aug-21 09:20 UTC
AW: [Xen-users] Deploying redhat clusters under Xen 3.0.2
> - can this change affects to all disks in the guest, included node > disk??Yes, it has affects to all for xen guest defined disks. Maybe in future we can define storage for xen guests nonshared by default or shared. This is only if you setup cluster with shared disk on one xen host.> - How can I setup virtual storage in config file, as a normal disk > without any param??I don''t now your question. Have a look here: http://www.cl.cam.ac.uk/Research/SRG/netos/xen/readmes/user/user.html#SECTIO N03300000000000000000 This is my storage config node1 for rhcs with gfs to play and learn about this. All is done by lvm: disk = [ ''phy:/dev/xenvg/xenRHEL4_3,ioemu:hda,w'', ''phy:/dev/xenvg/xenCLU1fs1,ioemu:hdb,w'', ''phy:/dev/xenvg/xenCLU1fs2,ioemu:hdc,w'' ]> - If I use GFS and two nodes writing at same time, can this virtual > storage be corrupted??No, gfs is developed for such scenarios. http://www.redhat.com/docs/manuals/csgfs/ Thomas> -----Ursprüngliche Nachricht----- > Von: xen-users-bounces@lists.xensource.com [mailto:xen-users- > bounces@lists.xensource.com] Im Auftrag von carlopmart > Gesendet: Montag, 21. August 2006 09:24 > Cc: xen-users@lists.xensource.com > Betreff: Re: [Xen-users] Deploying redhat clusters under Xen 3.0.2 > > Tim, more information: > > - I wneed to use GFS filesystem for this virtual storage. > - I do not use heartbeat, I have to deploy this configuration with > RedHat Cluster Suite. > - Only one network interface per node using 100Mb private netowrk. > > Thomas, > > About this: > > If you change in /etc/xen/scripts/block Line 105 and 116 from > echo local > to: > echo ok. > > I have some questions: > > - can this change affects to all disks in the guest, included node > disk?? > - How can I setup virtual storage in config file, as a normal disk > without any param?? > - If I use GFS and two nodes writing at same time, can this virtual > storage be corrupted?? > > Many thanks > > > > Tim Post wrote: > > On Fri, 2006-08-18 at 22:42 +0200, carlopmart wrote: > >> Hi all, > >> > >> I need to deploy different RedHat servers with Cluster Suite under > Xen > >> (using Intel VT hardware for hosts). To accomplish this, I need to > setup > >> a virtual shared storage disk to serve for several nodes. Can Xen 3.0.2 > >> support disk locking feature to deploy clusters (Load balancing and HA > >> configs) as vmware products support? Is this feature supported by xen? > >> And my last question: can I use virtual scsi disk to use as a shared > >> storage? > >> > >> Many thanks. > >> > >> > > > > Some more information about your cluster would be helpful :) How many > > nics per node, and is one of those nics talking to a private gig-e > > network? > > > > We use xen to help manage or completely contain everything from open SSI > > to our own pound / lighty / drbd / heartbeat based concoctions and quite > > frankly I can''t see doing without Xen in the future when it comes to > > both ha / load balanced and hpc clusters. > > > > Have you looked at gfs? > > > > Cheers > > -Tim > > > > > > > > -- > CL Martinez > carlopmart {at} gmail {d0t} com > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.405 / Virus Database: 268.11.3/423 - Release Date: 18.08.2006_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
carlopmart
2006-Aug-21 09:46 UTC
Re: AW: [Xen-users] Deploying redhat clusters under Xen 3.0.2
Many thanks Thomas. thomas.vonsteiger@bluewin.ch wrote:>> - can this change affects to all disks in the guest, included node >> disk?? > > Yes, it has affects to all for xen guest defined disks. > Maybe in future we can define storage for xen guests nonshared by default or > shared. This is only if you setup cluster with shared disk on one xen host. > >> - How can I setup virtual storage in config file, as a normal disk >> without any param?? > > I don''t now your question. > Have a look here: > http://www.cl.cam.ac.uk/Research/SRG/netos/xen/readmes/user/user.html#SECTIO > N03300000000000000000 > > This is my storage config node1 for rhcs with gfs to play and learn about > this. All is done by lvm: > > disk = [ ''phy:/dev/xenvg/xenRHEL4_3,ioemu:hda,w'', > ''phy:/dev/xenvg/xenCLU1fs1,ioemu:hdb,w'', > ''phy:/dev/xenvg/xenCLU1fs2,ioemu:hdc,w'' ] > >> - If I use GFS and two nodes writing at same time, can this virtual >> storage be corrupted?? > > No, gfs is developed for such scenarios. > http://www.redhat.com/docs/manuals/csgfs/ > > > Thomas > >> -----Ursprüngliche Nachricht----- >> Von: xen-users-bounces@lists.xensource.com [mailto:xen-users- >> bounces@lists.xensource.com] Im Auftrag von carlopmart >> Gesendet: Montag, 21. August 2006 09:24 >> Cc: xen-users@lists.xensource.com >> Betreff: Re: [Xen-users] Deploying redhat clusters under Xen 3.0.2 >> >> Tim, more information: >> >> - I wneed to use GFS filesystem for this virtual storage. >> - I do not use heartbeat, I have to deploy this configuration with >> RedHat Cluster Suite. >> - Only one network interface per node using 100Mb private netowrk. >> >> Thomas, >> >> About this: >> >> If you change in /etc/xen/scripts/block Line 105 and 116 from >> echo ‘local’ >> to: >> echo ‘ok’. >> >> I have some questions: >> >> - can this change affects to all disks in the guest, included node >> disk?? >> - How can I setup virtual storage in config file, as a normal disk >> without any param?? >> - If I use GFS and two nodes writing at same time, can this virtual >> storage be corrupted?? >> >> Many thanks >> >> >> >> Tim Post wrote: >>> On Fri, 2006-08-18 at 22:42 +0200, carlopmart wrote: >>>> Hi all, >>>> >>>> I need to deploy different RedHat servers with Cluster Suite under >> Xen >>>> (using Intel VT hardware for hosts). To accomplish this, I need to >> setup >>>> a virtual shared storage disk to serve for several nodes. Can Xen 3.0.2 >>>> support disk locking feature to deploy clusters (Load balancing and HA >>>> configs) as vmware products support? Is this feature supported by xen? >>>> And my last question: can I use virtual scsi disk to use as a shared >>>> storage? >>>> >>>> Many thanks. >>>> >>>> >>> Some more information about your cluster would be helpful :) How many >>> nics per node, and is one of those nics talking to a private gig-e >>> network? >>> >>> We use xen to help manage or completely contain everything from open SSI >>> to our own pound / lighty / drbd / heartbeat based concoctions and quite >>> frankly I can''t see doing without Xen in the future when it comes to >>> both ha / load balanced and hpc clusters. >>> >>> Have you looked at gfs? >>> >>> Cheers >>> -Tim >>> >>> >>> >> -- >> CL Martinez >> carlopmart {at} gmail {d0t} com >> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users >> >> >> -- >> No virus found in this incoming message. >> Checked by AVG Free Edition. >> Version: 7.1.405 / Virus Database: 268.11.3/423 - Release Date: 18.08.2006 > >-- CL Martinez carlopmart {at} gmail {d0t} com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Christopher G. Stach II
2006-Aug-21 12:53 UTC
Re: AW: [Xen-users] Deploying redhat clusters under Xen 3.0.2
carlopmart wrote:> Many thanks Thomas. > > thomas.vonsteiger@bluewin.ch wrote: >>> - can this change affects to all disks in the guest, included node >>> disk?? >> >> Yes, it has affects to all for xen guest defined disks. >> Maybe in future we can define storage for xen guests nonshared by >> default or >> shared. This is only if you setup cluster with shared disk on one xen >> host. >> >>> - How can I setup virtual storage in config file, as a normal disk >>> without any param?? >> >> I don''t now your question. >> Have a look here: >> http://www.cl.cam.ac.uk/Research/SRG/netos/xen/readmes/user/user.html#SECTIO >> >> N03300000000000000000 >> >> This is my storage config node1 for rhcs with gfs to play and learn about >> this. All is done by lvm: >> >> disk = [ ''phy:/dev/xenvg/xenRHEL4_3,ioemu:hda,w'', >> ''phy:/dev/xenvg/xenCLU1fs1,ioemu:hdb,w'', >> ''phy:/dev/xenvg/xenCLU1fs2,ioemu:hdc,w'' ] >> >>> - If I use GFS and two nodes writing at same time, can this virtual >>> storage be corrupted?? >> >> No, gfs is developed for such scenarios. >> http://www.redhat.com/docs/manuals/csgfs/ >> >> >> Thomas >> >>> -----Ursprüngliche Nachricht----- >>> Von: xen-users-bounces@lists.xensource.com [mailto:xen-users- >>> bounces@lists.xensource.com] Im Auftrag von carlopmart >>> Gesendet: Montag, 21. August 2006 09:24 >>> Cc: xen-users@lists.xensource.com >>> Betreff: Re: [Xen-users] Deploying redhat clusters under Xen 3.0.2 >>> >>> Tim, more information: >>> >>> - I wneed to use GFS filesystem for this virtual storage. >>> - I do not use heartbeat, I have to deploy this configuration with >>> RedHat Cluster Suite. >>> - Only one network interface per node using 100Mb private netowrk. >>> >>> Thomas, >>> >>> About this: >>> >>> If you change in /etc/xen/scripts/block Line 105 and 116 from >>> echo ‘local’ >>> to: >>> echo ‘ok’. >>> >>> I have some questions: >>> >>> - can this change affects to all disks in the guest, included node >>> disk?? >>> - How can I setup virtual storage in config file, as a normal disk >>> without any param?? >>> - If I use GFS and two nodes writing at same time, can this virtual >>> storage be corrupted?? >>> >>> Many thanks >>> >>> >>> >>> Tim Post wrote: >>>> On Fri, 2006-08-18 at 22:42 +0200, carlopmart wrote: >>>>> Hi all, >>>>> >>>>> I need to deploy different RedHat servers with Cluster Suite under >>> Xen >>>>> (using Intel VT hardware for hosts). To accomplish this, I need to >>> setup >>>>> a virtual shared storage disk to serve for several nodes. Can Xen >>>>> 3.0.2 >>>>> support disk locking feature to deploy clusters (Load balancing and HA >>>>> configs) as vmware products support? Is this feature supported by xen? >>>>> And my last question: can I use virtual scsi disk to use as a shared >>>>> storage? >>>>> >>>>> Many thanks. >>>>> >>>>> >>>> Some more information about your cluster would be helpful :) How many >>>> nics per node, and is one of those nics talking to a private gig-e >>>> network? >>>> >>>> We use xen to help manage or completely contain everything from open >>>> SSI >>>> to our own pound / lighty / drbd / heartbeat based concoctions and >>>> quite >>>> frankly I can''t see doing without Xen in the future when it comes to >>>> both ha / load balanced and hpc clusters. >>>> >>>> Have you looked at gfs? >>>> >>>> Cheers >>>> -Tim >>>> >>>> >>>> >>> -- >>> CL Martinez >>> carlopmart {at} gmail {d0t} com >>> >>> _______________________________________________ >>> Xen-users mailing list >>> Xen-users@lists.xensource.com >>> http://lists.xensource.com/xen-users >>> >>> >>> -- >>> No virus found in this incoming message. >>> Checked by AVG Free Edition. >>> Version: 7.1.405 / Virus Database: 268.11.3/423 - Release Date: >>> 18.08.2006 >> >> >I had CLVM, CMAN, CCS, and GFS set up on a development Xen cluster. I just got rid of Xen because we were needed the full machine performance. Basically, we were going in the opposite direction that virtualization is. :) It worked fine most of the time, but there are some things I would do differently. First, don''t let dom0 manage any of the storage. Use one of GNBD, iSCSI, AoE, etc. and dedicated private network cards for each domain. I wouldn''t even bother bridging vifs. Second, use the new credit scheduler. If you decide to not take this advice, expect to be turning your CMAN timeouts way up when you find your domains stalling and getting fenced multiple times a day. :) It would be nice if the dom0 <-> domU traffic worked so fence_xen functioned. If you can''t get it to work, say hello to fence_manual. Not fun. -- Christopher G. Stach II _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Christopher G. Stach II
2006-Aug-21 12:56 UTC
Re: [Xen-users] Deploying redhat clusters under Xen 3.0.2
carlopmart wrote:> About this: > > If you change in /etc/xen/scripts/block Line 105 and 116 from > echo ‘local’ > to: > echo ‘ok’. >That wasn''t necessary for me. I just defined the vbds with w! instead of w. Also, you really should use CLVM for consistent naming across the cluster if you want migration to work. That way, you also only have to export one block device. -- Christopher G. Stach II _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Javier Guerra
2006-Aug-21 13:13 UTC
Re: AW: [Xen-users] Deploying redhat clusters under Xen 3.0.2
On Monday 21 August 2006 7:53 am, Christopher G. Stach II wrote:> would do differently. First, don''t let dom0 manage any of the storage. > Use one of GNBD, iSCSI, AoE, etc. and dedicated private network cards > for each domain. I wouldn''t even bother bridging vifs. Second, use theI see why not using vif-bridging for storage, but why not to manage storage in dom0? having there the GNBD, iSCSI, AoE, device(s) and CLVM should work, and it seems would be the most manageable setup. would you share your (bad) experiences with Dom0-managed storage? -- Javier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
carlopmart
2006-Aug-21 13:17 UTC
Re: AW: [Xen-users] Deploying redhat clusters under Xen 3.0.2
Christopher, What do you mean when you say: "First, don''t let dom0 manage any of the storage"?? i need to setup vbds for virtual storage on dom0 machine, because this host have all disks!!! ... Using w! param only on virtual storage shared disks, both nodes can write at the same time using GFS??? Christopher G. Stach II wrote:> > I had CLVM, CMAN, CCS, and GFS set up on a development Xen cluster. I > just got rid of Xen because we were needed the full machine performance. > Basically, we were going in the opposite direction that virtualization > is. :) It worked fine most of the time, but there are some things I > would do differently. First, don''t let dom0 manage any of the storage. > Use one of GNBD, iSCSI, AoE, etc. and dedicated private network cards > for each domain. I wouldn''t even bother bridging vifs. Second, use the > new credit scheduler. If you decide to not take this advice, expect to > be turning your CMAN timeouts way up when you find your domains stalling > and getting fenced multiple times a day. :) It would be nice if the > dom0 <-> domU traffic worked so fence_xen functioned. If you can''t get > it to work, say hello to fence_manual. Not fun. >-- CL Martinez carlopmart {at} gmail {d0t} com _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
<thomas.vonsteiger@bluewin.ch>
2006-Aug-21 16:58 UTC
AW: [Xen-users] Deploying redhat clusters under Xen 3.0.2
What you mean with "use clvm". In domU with gfs I use clvm. Are you mean to manage storage with clvm in dom0 ? Becose I have only one xen host at the moment. Thank you for this tip "w!". I don''t here from this option befor. Thomas> -----Ursprüngliche Nachricht----- > Von: xen-users-bounces@lists.xensource.com [mailto:xen-users- > bounces@lists.xensource.com] Im Auftrag von Christopher G. Stach II > Gesendet: Montag, 21. August 2006 14:57 > An: carlopmart > Cc: xen-users@lists.xensource.com > Betreff: Re: [Xen-users] Deploying redhat clusters under Xen 3.0.2 > > carlopmart wrote: > > About this: > > > > If you change in /etc/xen/scripts/block Line 105 and 116 from > > echo local > > to: > > echo ok. > > > > That wasn''t necessary for me. I just defined the vbds with w! instead of > w. > > Also, you really should use CLVM for consistent naming across the > cluster if you want migration to work. That way, you also only have to > export one block device. > > -- > Christopher G. Stach II > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.405 / Virus Database: 268.11.3/423 - Release Date: 18.08.2006_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Christopher G. Stach II
2006-Aug-22 03:28 UTC
Re: AW: [Xen-users] Deploying redhat clusters under Xen 3.0.2
Javier Guerra wrote:> On Monday 21 August 2006 7:53 am, Christopher G. Stach II wrote: >> would do differently. First, don''t let dom0 manage any of the storage. >> Use one of GNBD, iSCSI, AoE, etc. and dedicated private network cards >> for each domain. I wouldn''t even bother bridging vifs. Second, use the > > I see why not using vif-bridging for storage, but why not to manage storage in > dom0? having there the GNBD, iSCSI, AoE, device(s) and CLVM should work, and > it seems would be the most manageable setup. > > would you share your (bad) experiences with Dom0-managed storage?Oh, it works, but not very well under high I/O load. You want to dedicate that single physical processor to dom0 for that, but even then, you will end up with pcpu contention in the domUs (if you''re running more vcpus than pcpus, minus the one for dom0.) Eventually, they lag so much that CMAN drops them and they get fenced. I''m sure that the credit scheduler will help, but I''m doubtful that it will help that much. It''s pretty clear to me that in such cases, you really should just let dom0 manage the domUs and let the physical hardware do the work (network I/O to some block device and the other cluster nodes.) I had been running this configuration in 3.0.2 since it came out. It wasn''t very happy. Why would you want a choke between your block devices, anyway? -- Christopher G. Stach II _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users