On Thu, Sep 17, 2009 at 02:36:39AM +0200, Christian Pernegger wrote: > > Hmm. So without dm-crypt no problem? The main effect of dm-crypt > > is to make the disk appear slower, because of the encryption. > > Unfortunately it's not *just* slower. Yes, the arrays would be 2x-3x > as fast without encryption, but that's not the point. It's that I/O > bandwidth isn't shared fairly at all. As if all crypt requests went > into one big FIFO ... (But then, maybe they do.) The stream with the > most/biggest requests then gets all the bandwidth. Yes. And that may be some s"synergetic" effect triggered by the slowness. At least that is one possible explanation. > > You could try this with a dummy-cipher that does not take encryption time. > > Excellent idea, what's the cipher string for that? I couldn't find > anything obvious in /proc/crypto or under > /lib/modules/.../kernel/crypto/. I have not tried this myself, but hit candidates are "ciper_null" and "ecb(ciper_null)". I have both (kernel 2.6.30.5) Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@xxxxxxxxxxx GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
