Date: Wed, 12 Mar 2003 00:57:14 +0100 From: Dean Strik <dean@stack.nl> To: Troy Settle <troy@psknet.com> Cc: freebsd-isp@freebsd.org Subject: Re: Mail Storage Reccomendations (3Ware vs Adaptec vs ....) Message-ID: <20030311235714.GA27853@dragon.stack.nl> In-Reply-To: <002201c2e703$cabdcdf0$aa8ffea9@abyss> References: <002201c2e703$cabdcdf0$aa8ffea9@abyss>
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Troy Settle wrote: > My current mail storage server is a C600 w/512MB and ~54GB of RAID5 > (amr0, Series 466). The machine (and drives) are coming up on 3 years > of age, and I'm ready to replace it. Performance has been acceptable, > but not stellar. > > The question of the day, is do I build a 3ware RAID5 solution (with like > 7*40GB drives of RAID5 and a hot spare), or do I stick with SCSI with > something like a Supermicro server > (http://www.supermicro.com/PRODUCT/SUPERServer/SuperServer6021H.htm) > with an Adaptec U160 0-channel RAID controller and 5*36GB and a hot > spare. > > Besides NFS, this machine will also be running a MySQL server with 1 or > 2 very small databases (for storing the vpopmail database). Whoa. "Besides NFS". So you export the mailboxes to other hosts? That's an important difference. Anyway, if disk performance is a problem, I'd go with SCSI RAID10: high performance read, good performance write. RAID5 means a performance penalty, even in hardware. With RAID10, even software RAID would give acceptable performance: software RAID is mostly expensive with RAID5. U320 SCSI probably isn't worth it. If possible, make the sytem disks (and swap) independent from the mail storage disks. Of course make sure that your NFS link is good. If you export the mailboxes to NFS, and the clients are not running FreeBSD, but e.g. Solaris, you may have a low performance NFS link because of differences in window sizes. You may need to tweak a lot then. Even when running FreeBSD, setting readahead and blocksizes in NFS mount options is advised. But note: NFS performance means tweaking. How does the mail get delivered to the mailboxes? I strongly advise against delivering over NFS. Put your sendmail/postfix/* logfiles on another disk than the storage files. How do clients access the mail storage? Do they use IMAP or POP3 to a machine which mounts the files over NFS? Consider cutting out the middle man: run IMAP/POP3 service on the storage machine if possible. Make sure you know where the bottleneck is. The MySQL server should not have a big impact. Unless the machine also works as a relay (avoid the storage/relay combination when possible), the databases are not big and not that often queried. If this would pose a problem, consider making regular dumps of the databases to standard Berkeley/*DBM files and using those in your daemons. On ATA controllers: the 3ware vs. Mylex is almost a holy war. In archives and on google you can find many experiences, but often contradicting. I have no personal experience with these. CPU should however not really be the problem. -- Dean C. Strik Eindhoven University of Technology dean@stack.nl | dean@ipnet6.org | http://www.ipnet6.org/ "This isn't right. This isn't even wrong." -- Wolfgang Pauli To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message
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