John G. Heim wrote: > From: "Jefferson Ogata" <[email protected]> > >> *Again*, this is why if you have particular performance requirements, >> you should consult with your database vendor to determine what bandwidth >> and IOPS you need, and benchmark your gear using different RAID configs. >> You may find that RAID 5 is just fine performance-wise, and you can get >> around 1.7 times the storage capacity with the same rack space, heat, >> and power load over RAID 10. Asking here you're just going to get people >> parroting Oracle's stale recommendations and speculating wildly without >> knowing anything about your workload. >> >> > > Well, its not really practical to suggest that I consult with my vendor. My > whole budget is $6000. This is just the Math Department at the University of > Wisconsin. I mentioned in my original message that our databases consist > primarily of spamassassin bayesian rules and horde3/imp web mail. Those do a > lot of updates -- well, a lot by our standards. Every time a spam message > comes in, it it is added to the bayesian rule set for the user. I'm going to > say that typically each user gets 100 spam messages a day and there are 200 > users. But each new rule consistes of several table updates. Even so, its > not like we're ebay. > > Anyway, speed of updates is critical because we can't have the mail system > getting bogged down by database updates. I put the bayesian rules in a mysql > DB in the first place because it was getting bogged down saving bayesian > data to bbm files on the mail server. > > I just want to make sure that I'm not setting myself up for a disaster. > If writes are an issue and the DB can fit in RAM and you don't mind losing a few writes, then you might try mounting the DB or bbm files in a tmpfs filesystem (aka ramdisk) with a sync to disk every 5 minutes or so. I read an article about someone doing that for ganglia data because the number of transactions was killing them.
Jason _______________________________________________ Linux-PowerEdge mailing list [email protected] https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
