On Tue, Feb 16, 2010 at 03:42:25PM -0500, Philipp Weis wrote: > How could it end up in the page cache for this setup? There is no > filesystem layer below the loop device. Any write that reaches the > loop device is passed through to lvm, then md and finally the disk. > Are you saying that there is extra caching going on at the lvm or md > layers? Yes, the block device node is a cached access mode, and uses the same pagecache as a filesystem uses.