On Saturday 03 January 2009 07:54 pm, Peter Manis wrote: > I have know people who have had both drives fail.
I've heard of it, too. But I've never seen it. And since we backup as well, and can restore quickly, I'm not that worried. > That aside RAID1 > is slow, you will have better performance by using RAID5, RAID6, > RAID10, RAID 0+1, or any of the many other RAID levels. Please show me statistics. My understanding is that RAID1 is fast at reading, slow at writing. Which fits our model (webhosting) perfectly. > Remember > this was a database server, a central location for the site's entire > database. For one database is usually always the bottleneck so > squeezing speed where you can is always a good thing not to mention > the requirement for better fault tolerance than mirroring. I didn't see anywhere in your first post on the topic that you meant in this particular circumstance. I'd agree with you; for a database server they should have been using a more fault-tolerant configuration. > It also > wasteful when it comes to data, you are using N*2 vs N+1 (r5) or N+2 > (r6). RAID10 and 0+1 are also wasteful, but may be better options > than RAID5/6 depending on the application. Yes, it's wasteful. > If I was in a situation where I was hosting a number of sites on a > number of servers I would not feel as strong about avoiding RAID1 > (depending on traffic), because it would not be a single point of > failure for the whole operation as this database server was. And this is a major concern; see more below... > I would never use RAID1 alone for a database server unless it was a > last resort and by last resort I mean, the machine is a 1U that will > only hold 2 drives or the machine only has 2 SATA/SCSI ports and no > way to add even a non-raid controller card... or I was 100% > completely broke. For a database server, I'd agree. And ... most (not all) of our hosting machines are 1U machines which hold two drives. We could use NAS in lieu of drives-in-servers, but then I'd worry about single-point-of-failure affecting more clients. I know of one webhoster who hosts over 6,000 domains on one sever. Yes, he uses NAS. I'd still rather do it my way (20 servers for 6,000 domains, each running two drives, RAID1). Thanks for your continued clarification. Jeff -- Jeff Lasman, Nobaloney Internet Services P.O. Box 52200, Riverside, CA 92517 Our jplists address used on lists is for list email only voice: +1 951 643-5345, or see: "http://www.nobaloney.net/contactus.html";
