Are there any good software-only (IE nothing expensive like NetApp) options for deduplication of SE Linux virtual machine images? A basic LVM writable snapshot allows creating a SE Linux test image with less disk space used. When LVM is used for Xen does the Dom0 do any caching? Ideally we would have the Dom0 do read-caching of the read-only device. http://micolous.id.au/archives/2010/01/23/linux-iscsi-cow-images-and-windows- integration/ Apparently dmsetup supports COW images, the man page on my system doesn't document it so maybe I would need a newer version. I'm not sure what benefit this would give over LVM snapshots given that LVM does it's stuff on top of DM anyway. http://user-mode-linux.sourceforge.net/old/UserModeLinux-HOWTO-7.html A COW block device for User-Mode Linux does the same thing but possibly works better with caching, the above URL documents UML COW as giving performance improvements but I'm unsure of LVM. Are there any others? I'm thinking of setting up a Linux virtual machine server for SE Linux training, and with most COW setups the initial relabel of the filesystem will put all the meta-data into a separate copy. So ideally there would be a way of deduplicating this. Also there's no guarantee that the disk blocks used would be the same so a simple un-COW operation on LVM or something probably wouldn't be a viable option. I believe that NetApp does this well, but there's no chance of getting that sort of hardware. -- russell@xxxxxxxxxxxx http://etbe.coker.com.au/ My Main Blog http://doc.coker.com.au/ My Documents Blog -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@xxxxxxxxxxxxx with the words "unsubscribe selinux" without quotes as the message.
