Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Thu, Aug 28, 2008 at 10:39:30PM +0200, Robert Heinzmann (ml) wrote: > Hello, > > I just watched the recording of the performance tuning webinar. The Q&A > points to > http://www.drbd.org/community/wiki/?tx_drwiki_pi1%5Bkeyword%5D=performance > for the specs of rum & kugel. > > I wonder what storage subsystem on rum & kugel looks like ? (Controler + > HDD) ? ah, right. that is an Adaptec 3405 RAID5 V1.0 with battery backup unit for the cache with 4x FUJITSU MAX3073RC in RAID5 as PV of LVM2. drbd and everything else is sitting in LVs on that. btw, when you have a non-volatily, battery backed up write cache in the controller, don't forget to disable the (typically volatile!) on-disk cache. or you may face data loss on power outage anyways. you may enable the read cache on disk, if you think it is worth it. in this setup, that was done by modprobe sg for i in `seq 4`; do sdparm -s WCE=0,RCD=0 -S /dev/sg$i ; done see man sdparm for details, and your controller manual for other ways to achieve the same if the single disks are not visible as sg devices to the OS. cheers, -- : Lars Ellenberg : LINBIT HA-Solutions GmbH : DRBD®/HA support and consulting http://www.linbit.com DRBD® and LINBIT® are registered trademarks of LINBIT Information Technologies GmbH __ please don't Cc me, but send to list -- I'm subscribed