On Tue, 2007-11-20 at 09:29 -0800, malahal@us.ibm.com wrote: > S. J. van Harmelen [svh@dds.nl] wrote: > > > > Now my thoughts where to take snapshots on the storage server. So that > > would mean I would take a snapshot of lv_storage. This should not be a > > problem. But what if virtual machine 2 crashes and has to be restored? > > > > In that case I cannot restore lv_storage with a dd command, because then > > all the data will be restored (lv_virtualmachine1 and > > lv_virtualmachine2, because they are both on lv_storage). So is it > > possible to "restore" only lv_virtualmachine2 when I took a snapshot of > > lv_storage? > > I see, it is possible but a bit cumbersome. You should be able to run > LVM on the storage server on the restored/old data (LVM on top of LVM??) and > get the data for the lv_virtualmachine2 from the storage server to > XenSource (ftp/tar whatever method). Then, restore that data (tar > extract) at XenSource. > > If things are NOT changing at the XenSource LVM, you could just "dd" on > the crashed LV, but things may go really bad otherwise. > > Any better method(s)??? Well of course this could also be done from the Xen server. Then there is no need for LVM on the storage server and the lv_storage part can be left out of this picture. I could then create a second iSCSI target on a second LUN to export to the Xen server so that Xen can take snapshots to that second exported disk. If a problem does occur, then a restore is simple because then I could do a dd from the snapshot lv (on the Xen server) to the other lv (also on the Xen server). But how about network traffic on this one? Everything I do will go across iSCSI so it will go over the network. And then I will manually have to greate lv-snapshots for each virtual machine instead of just one big lv-snapshot as I could do when lv_storage exists. Any thoughts? > > > I can see the PV and LV's Xen created on lv_storage on the storage > > server when I run pvs by the way... > > Yes, you will see them but you want the storage server's LVM to NOT use > them under normal conditions. > > BTW, for backup, you may want snapshot-origin target rather than snapshot > target directly.. _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
