Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Le 19/11/2013 22:20, Arnold Krille a écrit : > On Tue, 19 Nov 2013 14:29:32 +0100 "FDS | Forensik Data Services" > <office at fds.at> wrote: >> Just clarifying my understanding of an UpToDate-Status of a DRBD >> Resource in Dual Primary Mode on 2 nodes. >> Does a MD5-Hash calculation of both resources lead to equal MD5 >> values? > That depends. Prerequisites: > - Both primaries are unmounted. > - Both primaries are completely synced from the os/fs point of view. > (That is "sync" has been run and thus all write-buffers are cleared.) > > Then an md5-hash of the drbd-device on both machines should return the > same. Also md5-hashes of all the underlaying devices should(*) return > the same. A MD5 match proves everything is ok BUT a mismatch does not always mean trouble. There may be harmless differences if the layers above "cut corners" and modify blocks in memory after they've been sent to DRBD. RaiserFS and swap memory are known to do this. See "Notes on data integrity" at http://www.drbd.org/users-guide/re-drbdconf.html for more examples and details. Lionel Sausin.