I would agree about the Raid-5 thing, we had 3 Exim MTA's load balanced each with 4 disks in Raid 5 and the throughput was terrible. All we did was swap that for 2 raid-1 disk sets (One for OS, one for mail spools) and we saw a 100 fold increase in performance.
Our machines are now purring along (and we didn't have to use the no-atime option yet). -Andy- > -----Original Message----- > From: Jaye Mathisen [mailto:[EMAIL PROTECTED] > Sent: 16 August 2005 19:14 > To: Simon Chappell > Cc: [email protected] > Subject: Re: [exim] HArdware Suggestions for exim courier-imap > > Nothing wrong with your config, generally speaking more > spindles are better. > > We ran just a hair under 20k user with qmail and > courier-imap/pop3 off a dual P3 box. > > The key was RAM, fast RAID (stay away from RAID 5 if you can, > stick with 10 if you can, and spread teh load out. > > We used 3ware 12 port 8000 series RAID cards, the new 9000 > cards are even faster. > > SO get yourself a good 12 port 3U SATA enclosure, use the WD > 10k drives, or other good high-memory caching drives, create > several different arrays to do different parts (storage > separate from queue separate from OS separate from database), > and go for it. > > There are arguments for and against software vs hardware > RAID. the 3ware RAID is a no brainer, integrates into > FreeBSD and linux, has an easy to use console management > tool, and for us, was rock solid. > > Or get a good supermicro box with the adaptec ZCR raid. > > Or get 2 lower-end boxes, and a good load balancing switch, > an have some failover capability as well. > > > On Tue, Aug 16, 2005 at 06:48:46PM +0100, Simon Chappell wrote: > > Thanks to everyone for the help. It has been interesting getting > > everones opinions as most of the information about "What to Buy" is > > pretty non-existant. > > > > > > The things I have noted is if the bean counters give us the > go ahead > > for a large lump of money then > > > > Branded Server eg HP or even Sun if the budget allows Dual > Opteron or > > Dual Core 3Ghz+ 4Gig ram Ultra320 Raid Card 3x 145GB drives Raid5 > > Maildirs > > 2x 80GB drives Raid1 OS > > > > > > IF not and we have to go cheaper (More likely in the real world) > > > > Whitebox > > Dual Opteron or Dual Core 3Ghz+ > > 4Gig ram > > 4XSATA 200GB Raid 0+1 Maildir > > 2xSATA 160GB Raid1 OS > > > > Probably about 10 grand gap in between but at least I have a good > > bearing and should end up somewhere in the gap in the middle. > > > > That much processing power should cover us for the > foreseeable future > > including expansion and more users over the current 700. > > > > Also adding the atime to the fstab may have bought us time to think > > (or time to put of until it becomes a problem again) and run some > > tests of our own to help us make the right choice. > > > > Thanks Again > > > > Simon > > > > > > > > > > Mike Meredith wrote: > > > > >On Tue, 16 Aug 2005 11:57:06 -0400, Chris Meadors wrote: > > > > > > > > >>I actually prefer the Linux kernel's software RAID over > controllers > > >>these days. The data is stored in a non-proprietary on > disk format, > > >>so one isn't as the mercy of the controller if something goes > > >>horribly wrong. I've even found the performance to be > better than > > >>the cheaper hardware SCSI RAID cards on the market. > > >> > > >> > > > > > >Even if the on disk format is documented, I'd still rather recover > > >from backups. Mind you there's other reasons for not > liking "intelligent" > > >controllers (recalling a certain RAID controller on which you were > > >supposed to run a parity check once a week, which involved > shutting > > >down a large Alphaserver and booting off a boot floppy > with the RAID > > >controller software on). > > > > > > > > > > > -- > > ## List details at http://www.exim.org/mailman/listinfo/exim-users > > ## Exim details at http://www.exim.org/ ## Please use the Wiki with > > this list - http://www.exim.org/eximwiki/ > > > > > > !DSPAM:4302286a99161666570589! > > > > > -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
