On Fri, Jun 13, 2008 at 09:08:48AM +0200, Wojciech Puchar wrote: > >>Does gstripe read an entire stripe at a time? If so, why do that instead > >>of > >>just reading a few requested blocks? If not, then is there any advantage > >>to large stripes? > > > >Apparently it won't read anything larger than your stripe size which > >defaults to a miserable 4k. > > > depending from what's needed, but unless i need just huge linear transfer, > i set stripe size to something huge, like 256MB. > > then single read is rarely split on 2 disks, while multiple reads have > good chances to touch different drives
Come to think of it I didn't try setting the stripe size larger than the ATA max transaction size of 128k. Still, I don't understand what is going on when I use md5(1) on a gigabyte file hosted on a gstripe partition with 128k stripes that "systat -v" reports transactions are usually between 42k and 43k each? On a non-striped filesystem the same operation runs 126k to 127k transfers. Transfer bandwidth seems to be limited by the number of transactions per second more than the size of the transaction. -- David Kelly N4HHE, [EMAIL PROTECTED] ======================================================================== Whom computers would destroy, they must first drive mad. _______________________________________________ firstname.lastname@example.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"