On Wed, Feb 03, 2010 at 07:54:05PM -0500, Bill McGonigle wrote: > I'm wondering what folks are doing for uniquely identifying plain disks > in their virtual machine configs. > > For instance, I'm trying out the new Xen version and stuck a couple SATA > drives in a box. I'd like to use them as physical devices, but not > break my vm config if I re-cable the drives (or move them to another > machine). > > I could create a degraded RAID mirror, and then reference them by mdX > and let md worry about the UUID's, but that's ugly. If I were using > luks on the drives they'd get tagged and could be referenced uniquely. > Same with iscsi, those are available uniquely under /sys. > > Maybe something with device mapper? But I'm actually interested in > benchmarking ZFS through Xen with this, so I'd hate to add another layer > just for this purpose, since it's only needed at setup time. I could > script some ugly hacks but I'd rather not. > > I was hoping to find a /sys/block/scsi/model/serialnumber type of thing > symlinked back to the ../../devices/pci... , but I didn't. So, I hope > I'm missing something obvious and folks here have this solved.
I wonder if you'd be better off uniquely identifying the filesystems instead of the devices. Filesystems have a unique ID: # tune2fs -l /dev/sda1 | grep UUID Filesystem UUID: 868b1447-0ec5-41bf-a2e5-6a77a4c9b66d and you can use this to mount the filesystem, eg in /etc/fstab: UUID=868b1447-0ec5-41bf-a2e5-6a77a4c9b66d /boot ext3 defaults 1 2 This is well tested too -- all Fedora installs use UUIDs like this. This will survive physical rearrangement of the disks containing the filesystem, and even work if you decide to turn the filesystem into a virtual disk. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://et.redhat.com/~rjones/virt-df/ _______________________________________________ virt mailing list [email protected] https://admin.fedoraproject.org/mailman/listinfo/virt
