Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi, On Wed, 12 Sep 2012 09:42:47 -0400 "Dan Barker" <dbarker at visioncomm.net> wrote: > a) use oflag=direct or dd will just test caching. Especially if you only copy 11MB. Use oflag=direct and copy much more data. And then a tip from some very practical experience: Test with a filesystem-benchmark like dbench. dd only tests sequential read/write, which isn't really of any practical use case unless you want to write and read large movies. Everything else from recording DAWs to databases to office usage is all random-access and fast reads are not helping when you really need low seek-time-induced latency. And that seek-time latency of drbd gets more important when you use internal meta-data because then every write has to be marked in the meta-data at then end of the partition. When placing the external meta-data on a different disk (maybe even on an ssd next to the super-fast-db-vm-image), we see an improvment of factor 2 in dbench's results for IO-rate. Have fun, Arnold -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 198 bytes Desc: not available URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20120912/6cd37b85/attachment.pgp>