<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>Am 18.12.2008 um 17:27 schrieb Lars Ellenberg:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>On Thu, Dec 18, 2008 at 04:46:10PM +0100, Thomas Reinhold wrote:<br><blockquote type="cite">Hi, <br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I've done a little further testing and ran DRBD directly on top of the raid set<br></blockquote><blockquote type="cite">(without using dm_crypt). Still got the same disk flush errors when having<br></blockquote><blockquote type="cite">flushing enabled. <br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">So can I assume that either the lower level scsi driver megaraid_sas (Debian<br></blockquote><blockquote type="cite">2.6.18.6-amd64) or the raid controller (LSI MegaRaid 1078) does not support<br></blockquote><blockquote type="cite">flushing?<br></blockquote><br>absolutely.<br><br><blockquote type="cite">And another question: Can disabling flushing in DRBD cause any other problems<br></blockquote><blockquote type="cite">than data corruptions at power loss?<br></blockquote><br>I'd say "no" if you promise not to sue me in case I'm wrong.</div></blockquote><div><br></div>How could I sue you for using a free product? I would have to buy a support contract first ;-)</div><div><br></div><div>Anyways, thanks for your help! I have disabled the raid controller cache for now, as I dislike the idea of having too much data in cache (even though we are using an UPS). </div><div><br></div><div>The disk caches are still enabled, however, as the performance impact of disabling both caches would be too great. We'll see how that works with XFS. </div><div><br></div><div>If we encounter any problems, I'll get back to the list. </div><div><br></div><div><br></div><div>Regards, </div><div><br></div><div> Thomas</div><div> </div><div><br></div><div><blockquote type="cite"><div><br><br>-- <br>: Lars Ellenberg<br>: LINBIT | Your Way to High Availability<br>: DRBD/HA support and consulting <a href="http://www.linbit.com">http://www.linbit.com</a><br><br>DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.<br>__<br>please don't Cc me, but send to list -- I'm subscribed<br>_______________________________________________<br>drbd-user mailing list<br><a href="mailto:drbd-user@lists.linbit.com">drbd-user@lists.linbit.com</a><br><a href="http://lists.linbit.com/mailman/listinfo/drbd-user">http://lists.linbit.com/mailman/listinfo/drbd-user</a><br></div></blockquote></div><br></body></html>