Il 25/08/2014 20:13, Andrew Martin ha scritto: > Even if the python daemon or apache2 did not fsync the modified files, isn't > there some action that the OS takes periodically to flush dirty pages to > disk? > This seems to be implied in the SuSE documentation: > https://www.suse.com/documentation/sles11/book_kvm/data/sect1_1_chapter_book_kvm.html > "the normal page cache management will handle commitment to the storage > device."
... using fsync :) > In the case of the files uploaded by apache2, they were added to the server > days > before the power outage, so it seems like there would have been ample time > for > those changes to have been flushed. Remember that cache=writeback has a huge cache, whose size is several gigabytes. At some point there was a QEMU bug that caused the guest not to do fsyncs. It was fixed by commit ef5bc96268. Paolo
