Hello, 13.10.2009 14:27, justAck wrote: > Arno, > > > Arno Lehmann wrote: >> ... >>> a) result file will be most likely not fragmented on disk at all >> This is most likely in the situation you outline. >> ... >> >> The most common reasons for slow restores, in my experience, are >> ... >> > > Thanks for quick and useful help. > I meant file access _after_ it is restored, not restore speed.
Ok... that's quite a different thing. > I need to do some more tests, but it looks that just > cp /restored/file > /dev/null > is performed 20% slower speed than copying of other files. This is very interesting... I doubt that Bacula can be the cause for this. It seems possible, though, that very shortly after a large set of files was restored, the buffers and cache are occupied by the files last restored and thus access to other files can be slower. But that should only be a temporary problem. I don't really believe that... in other words, I have no idea what could cause the behaviour you observe. > Doesn't bacula have some "image backup" format, when raw filesystem is > copied and then restored back? (This is only situation I can imagine which > keeps file fragmentation). Bacula has no special feature to do that, though you can back up raw partitions and restore those images, but then the fragmentation would be exactly the same as before - and I doubt that raw partition back up is used very often as it tends to waste space. > Maybe some cache is involved, need to test deeper, just wanted feedback > about possible scenarios. See above - I'd try vmstat 1 during a restore and subsequent read performance test, then wait a while, and do a nother read performance test. Arno > Thanks again! -- Arno Lehmann IT-Service Lehmann Sandstr. 6, 49080 Osnabrück www.its-lehmann.de ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
