>>>>> On Tue, 12 Jun 2007 14:14:56 -0700, Ross Boylan said: > > The Berkeley Database apparently requires that hot backups read disk > pages atomically. They note that most system cp commands do so; I've > searched the manual, FAQ, and newsgroups, but can't find how bacula > operates when reading a file. > > Does anyone know if I can count on the reads taking whole pages?
Generally, no. Specifically, possibly, at least if the page size is a factor of 65536, you don't set sparse=yes, the OS guarantees that a call to read(2) with a page aligned size will do it and also the network allows it. In these cases, it looks like the current read size equals the network buffer size (see Maximum Network Buffer Size). You could try using strace to see what bacula-fd is doing in practice. __Martin ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
