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From: Johannes K. <oj...@gm...> - 2007-11-15 12:43:01
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Hi, Marcelo Vanzin schrieb: > I think Elliot's comments are not 100% accurate. :-) The purpose of > the driver is not really to make backups easier, but to make disk > snapshots more consistent, by flushing all data that is cached in > memory before taking a snapshot and preventing applications from > writing to disk during the snapshot. Ah, I see. > So it's not really related to being able to mount vmdk files or > anything like that - it's just a helper driver that runs in the > guest, which is triggered by the snapshotting code in some VMware > products. OK. > The way it works is the tools daemon (vmware-guestd) receives a > command to "freeze" the filesystems in the VM, and it then tells the > driver to do that. The driver flushes all caches and "freezes" the > filesystems (meaning no writes are allowed until it's "thawed"). The > VMware code in the host then takes a snapshot and notifies > vmware-guestd that it's done, and then it tells the driver to "thaw" > the filesystems, resuming normal operation. Thanks for that explanation. I was hoping this could be the right place to ask for the mount-vmdks-feature on linux, but apparently it was not... ;-( Thanks anyway, OJ --=20 They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety. (Benjamin Franklin, 1759) |