Date: Wed, 6 Jun 2001 10:18:26 +0930 From: Greg Lehey <grog@FreeBSD.org> To: groggy@iname.com Cc: freebsd-questions <questions@freebsd.org> Subject: Re: raid/vinum/ide Message-ID: <20010606101826.C39199@wantadilla.lemis.com> In-Reply-To: <200106060041.QAA12255@en26.groggy.anc.acsalaska.net>; from groggy@iname.com on Tue, Jun 05, 2001 at 04:41:59PM -0800 References: <200106060041.QAA12255@en26.groggy.anc.acsalaska.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tuesday, 5 June 2001 at 16:41:59 -0800, groggy@iname.com wrote: > i am facing 2 choices i believe after checking out various > ways of providing effective hard drive speed/redundancy for a > DB. it seems RAID 10 is the best way to go if you can afford > the space lost compared to RAID5. so - i am looking for any > recommendations regarding these 2 IDE based methods: > > 1. vinum RAID10 (one drive per IDE controller). > * downside seems to be lack of hot-swappability. Correct. > * system needs to come down and be serviced to make a swap. Depending on the service. As you said before, IDE isn't hot swappable. > * vinum maybe slower than a 2 or 4 drive external solution There's no reason to believe this. It could be faster. > 2. Promise external IDE RAID storage with SCSI interface > capable of 4 IDE drive each on their own controller > (UltraTrak100) http://www.promise.com > * expensive ($1500 or so) > * onboard CPU (i dunno how fast this would make RAID5 on it) Check the speed of the onboard CPU. They're usually very slow. > * hotswappable IDE interface (ie - user maintainable) IDE isn't hot swappable. Anything which claims to do it is making tradeoffs. SCSI-connected RAID is not the best performer; you can get bottlenecks in the SCSI connection. Theoretically you can transfer 35 MB/s to an IDE disk; RAID often transfers in parallel, so your SCSI interface needs to be at least 140 MB/s (i.e. in practice 160). Is it? In addition, once the data gets to the controller, it needs to be rearranged before it can be put on the disks. The converse applies for reading. > this will be a production machine whose 24/7 reliability is critical. > please reply off the list as well as i am not subscribed. > i am mainly concerned with A) SPEED B) RELIABILITY/MAINTAINABILITY Sounds like you need a high-end RAID adaptor. Greg -- When replying to this message, please copy the original recipients. If you don't, I may ignore the reply. For more information, see http://www.lemis.com/questions.html See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010606101826.C39199>