On Wed, 16 Jun 1999 17:26:16 +0300 (IDT), Evgeny Stambulchik <[EMAIL PROTECTED]> wrote: >[EMAIL PROTECTED] (Udi Finkelstein) wrote: > >> (1) The kernel reports that the BIOS says that /dev/hda is PIO, while >> /dev/hdb >> and d/ev/hdc use DMA. weired. > >BIOS settings, probably? I wouldn't have written the above as "weired" if all 3 disks didn't have the *exact* same BIOS settings (which is "Auto", BTW.). >> measured performance with hdparm -t /dev/hd[abc] and got a disappointing >> 2.3MB/s. > >Forget about hdparm, it's a toy (I mean, hdparm -t). Use bonnie. What is bonnie? As for hdparm, at least it gives me a crude hint. >> Now comes the RAID part. I made a linear raid > >Why not RAID0? Generally, you'd get much better perfromance and could tune >it to your specific needs. I've once done more or less extensive benchmarks; Why? because linear, unlike RAID0, can be expanded more easily if I want to (if I add a 4th disk). Besides, for if the 3 disks used for RAID are also used for other things (swap & system) I will not be surprised to see linear gets better results if swap is on disk1, system on disk2, and the linear array starts on disk3. ofcourse, once the linear array grows bigger and starts spreading on other disks, you'll lose. Also, with 16MB/s coming out of the disks even in linear mode, it outperforms the 100MBit/s ethernet it's shared through, so it really doesn't matter. >see http://plasma-gate.weizmann.ac.il/~fnevgeny/raid/raid0.gif. Also, >comparison of performance of different (software) RAID levels: >http://plasma-gate.weizmann.ac.il/~fnevgeny/raid/raid.gif. Interesting graphs. I may be tempted to try after all... >Regards, > >Evgeny bye, udi n.b. my NFS problems were solved this morning. it was a permission problem on the Solaris directory over which the NFS share was mounted. It seems the directory wasn't umaske'ed as 1777 after all (it *was* 1777 in my tests on a single machine, but the guy installing it on the other 10 machines f*cked it up). ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
