Hi, I''m starting out with xen by trying to convert my existing gentoo server to be a domU under a newly created gentoo dom0. I have the dom0 running nicely and have most of the domU up, but the original server had an md/evms setup for home etc. I thought I could export the block devices to the domU and have md pick them up, but it is failing to do so. It writes md: Autodetecting RAID arrays. md: autorun ... md: ... autorun DONE. to the console, but there is nothing in /proc/mdstat nor does evms find the RAID or setup /dev/evms/ nodes. Before I waste time trying to get this up and running; is it possible to run MD/EVMS on a domU? I have not compiled MD or EVMS into the dom0 kernel, so that it doesn''t try to build the RAID. Any ideas? Andy _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Andy Repton wrote on 12/12/2005 04:16:33 PM:> Hi, > > I''m starting out with xen by trying to convert my existing gentoo > server to be a domU under a newly created gentoo dom0. > > I have the dom0 running nicely and have most of the domU up, but the > original server had an md/evms setup for home etc. I thought I could > export the block devices to the domU and have md pick them up, but it > is failing to do so. It writes > > md: Autodetecting RAID arrays. > md: autorun ... > md: ... autorun DONE. > > to the console, but there is nothing in /proc/mdstat nor does evms > find the RAID or setup /dev/evms/ nodes.First off, do not have both RAID autodetect and EVMS discover your RAID arrays. (That restriction needs to be noted more prominently in the EVMS docs.) They conflict with each other. Either disable RAID autodetect (use fdisk''s "t" command to change the partition types to 83 (Linux)) and let EVMS discover the arrays, or disable RAID support in EVMS by deleting the md-*.so plug-in in /lib/evms/<version>/. If you disable RAID support in EVMS you will have to use the RAID tools separately to manage the arrays and EVMS to manage the rest of the devices, which kind of defeats the purpose of EVMS to be the one place to go for all your volume configuration needs.> Before I waste time trying to get this up and running; is it possible > to run MD/EVMS on a domU?Off hand I don''t see any reason why you should not be able to use MD RAIDs and EVMS in a domU. You should be able to apply the instructions at http://evms.sourceforge.net/convert.html to the disk(s) being used in the domU. Any kernel patches you want would be applied to the domU kernel. You should be able to skip the updates to the boot loader (step 8) since dom0 does the booting of the domU. All the other steps you should be able to do within the domU once it is booted.> I have not compiled MD or EVMS into the dom0 kernel, so that it > doesn''t try to build the RAID.You should not need MD or EVMS in the dom0 kernel. dom0 just serves up the devices to the domU. The domU then determines how it wants to use them. Steve D. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks for the info Steve, (apologies, you''ll receive this twice as I forgot to reply to the list)> First off, do not have both RAID autodetect and EVMS discover your RAID > arrays. (That restriction needs to be noted more prominently in the EVMS > docs.) They conflict with each other. Either disable RAID autodetect (use > fdisk''s "t" command to change the partition types to 83 (Linux)) and let > EVMS discover the arrays, or disable RAID support in EVMS by deleting the > md-*.so plug-in in /lib/evms/<version>/.I checked and the partitions are type 83.> Off hand I don''t see any reason why you should not be able to use MD RAIDs > and EVMS in a domU.I''ve re-emerged evms to see if that was the problem but no change. The kernel has all of the LVM/DM options compiled in. When I evms_activate -d 9, I get three lines of: _3_ LocalDskMgr: check_multipath: Cannot get list of DM devices. in my log file. Could this point to the problem?> You should not need MD or EVMS in the dom0 kernel. dom0 just serves up the > devices to the domU. The domU then determines how it wants to use them. >That''s my understanding too, so there must be a detail I have missed somewhere! Andy _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Andy Repton wrote on 12/13/2005 06:25:26 AM:> Thanks for the info Steve, > > > First off, do not have both RAID autodetect and EVMS discover your RAID > > arrays. (That restriction needs to be noted more prominently in theEVMS> > docs.) They conflict with each other. Either disable RAID autodetect(use> > fdisk''s "t" command to change the partition types to 83 (Linux)) andlet> > EVMS discover the arrays, or disable RAID support in EVMS by deletingthe> > md-*.so plug-in in /lib/evms/<version>/. > > I checked and the partitions are type 83.That''s good. The MD autodetect kernel code shouldn''t find them, hence, you should not see anything in /proc/mdstat until evms_activate is run.> > Off hand I don''t see any reason why you should not be able to use MDRAIDs> > and EVMS in a domU. > > I''ve re-emerged evms to see if that was the problem but no change. > > The kernel has all of the LVM/DM options compiled in.I assume you mean the domU kernel, right?> When I evms_activate -d 9, I get three lines of: > > _3_ LocalDskMgr: check_multipath: Cannot get list of DM devices. > > in my log file. Could this point to the problem?That looks like a clue. Sounds like DM is not in the kernel or the mechanism to talk to DM is broken. Please send me the gzipped evms_engine.log. I''ll see if there are any other clues in it that might help. Steve D. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users