Difference between revisions of "GSP Virtualisation with Xen"
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(from http://forums.citrix.com/thread.jspa?threadID=250603) | (from http://forums.citrix.com/thread.jspa?threadID=250603) | ||
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| + | == How NOT to copy your LVMs from RHEL5 == | ||
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| + | The default image format in an SR is based on "VHD" disk images, that are distributable across VMs and contain some (compressable) meta-data about sparseness. Overwriting an LVM which was ''supposed to contain'' an VHD image with a raw disk image will make the SR corrupt. So '''if''' you do: | ||
| + | * create a virtual disk with the default (XenCenter) tools in a SR | ||
| + | * then active the LV on an XCP server, e.g. with <tt>lvchange -a y /dev/VG_XenStorage-e5d0e83a-7e70-3d28-31ab-ed98bfb68368/VHD-74e94bbc-b0e5-4e76-b507-12897b9b2625</tt> | ||
| + | * copy the data from remove into this activates LV, and wait for it to complete (you '''cannot''' use the LV in a distributed setup as long as it is active on a single XCP host): <tt>dd if=/vm/mach/images/rooier.img bs=64M | ssh -A davidg@salado "ssh -A root@vms-piet-16.inst.ipmi.nikhef.nl 'dd of=/dev/VG_XenStorage-e5d0e83a-7e70-3d28-31ab-ed98bfb68368/VHD-74e94bbc-b0e5-4e76-b507-12897b9b2625 bs=64M'"</tt> | ||
| + | * de-activate the LV on the import host <tt>lvchange -a n /dev/VG_XenStorage-e5d0e83a-7e70-3d28-31ab-ed98bfb68368/VHD-74e94bbc-b0e5-4e76-b507-12897b9b2625</tt> | ||
| + | * create a new VM (typo "Other" seems to be needed) and use the newly-populated disk image as the disk for the VM | ||
| + | * try it out ... | ||
| + | '''it will break the SR''' and you loose all images on it (since the MGT data is support. | ||
| + | Recover using http://support.citrix.com/article/CTX122001: | ||
| + | # open a console on the master XCP server | ||
| + | # Back up LVM metadata | ||
| + | vgcfgbackup | ||
| + | # Run the following command to see the LV which is causing trouble and that is causing the SR not to be scanned. | ||
| + | lvscan | ||
| + | # Remove the clone logical volume. Note: Make sure the correct Logical Volume is deleted. | ||
| + | lvremove /dev/VG_ XenStorage-8d418f1a-107e-472f-5453-b24c88e7428e/VDI_8e4b4263-f9af-45f3-b97e-afa5481ea2a1 | ||
| + | #.Run the following command to scan the SR, or use XenCenter | ||
| + | xe sr-scan uuid=<UUID of SR for the VM>. | ||
| + | |||
| + | You may need to forget about the SR first and then re-attach it (but DO NOT FORMAT the SR on attaching ;-) | ||
