On 9/3/2013 3:06 AM, Marian Csontos wrote:
Buffers may be more relevant metric as the I/O among snapshots is "shared" on block device level.
---- I am not going to say this isn't true, BUT, some parts of the kernel seem to report different block numbers for files on the same device when you mount the same device (or possible subtrees of a same device) at alternate mount points via "bind". I have my "/usr/share" physically located on my "/home" partition under "/home/share". In moving files from /usr/share/<subdir> to /home/share/<subdir2>, the coreutils "mv" cmd, actually does a file copy -- vs. when a file is detected as being on the same device, it usually does a simple rename. If 'mv' is seeing different device id's for a file, it's *less probable*, but possible that such misinformation could exist at lower levels in the kernel (?). Do you know whether or not the kernel "knows" they are on the same device, or is it possible the buffer area of the kernel has the same bug as the upper level that is reporting different devices to "mv"? _______________________________________________ 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/
