On Saturday 22 Dec 2001 19:42, Gary Huntress wrote: > I've just checked my IDE parameters for one of my linux mysql servers. > Using hdparm -c -d I've discovered that I'm running at the default 16 bit > non DMA. I'm assuming that enabling both of these should increase > performance, possibly significantly. > > However, I'm concerned about doing this 1) on the fly with the server up > and 2) doing it at all. Can anyone comment on linux hdparm performance > tuning for mysql and the possibility of table corruption?
I have found that using hdparm will either work, or it will hang the disk/bus immediately. Therefore, you should NEVER do it to a live, running server with disk I/O constantly occuring. Shut down server deamons, such as MySQL before you use hdparm or anything else to tune disks. As for performance, I have often seen performance improve by 2-10 fold when proper hdparm parameters were used to tune up the disks. So yes, it is very much worth it, but no, do not do it on a running server - reserve a few minutes of downtime before you start tuning things, as you will inevitably eventually push things to far and it will crash. Also never set the -k1 -K1 parameters before you've insured that the settings will work, as sometimes an automatic bus re-set will prevent a thorough crash. I don't know what distribution you are running, but on RedHat, there is a file /etc/sysconfig/harddisks where you can specify the parameters when you are done with tuning, so they get re-applied every time the machine boots up. Bear this in mind when doing disk-swaps. Regards. Gordan --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
