I actually normally configure them for RAID5...typically 4 drives striped and 1 drive parity. However, I've also setup 3 drives striped and 1 drive parity. A little slower, but LOTS more reliable.
Now having said that, I've also done nutso and went crazy once and did a mirrored RAID5 across two jbods...but this was a financial system that was logging fund transfers....so I figured we should be paranoid about it. Can't remember what it was, but I think some folks call it RAID10. /brian chee University of Hawaii ICS Dept Advanced Network Computing Lab 1680 East West Road, POST rm 311 Honolulu, HI 96822 808-956-5797 voice, 808-956-5175 fax ----- Original Message ----- From: "Charles Lockhart" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, June 05, 2002 10:29 AM Subject: Re: [luau] SANs > > Thanks Brian, > > Question, as I understand it, these arrays are typically set to RAID-0 for > striping across the drives, thereby increasing throughput. Assuming this > is correct, do you know how many drives are required, or typically > required, for this? > > -Charles > > On Tue, 4 Jun 2002, Brian Chee wrote: > > > Hmmmm.....let's see how well this can be done in a nutshell.... > > > > SAN's come in several flavors, but the idea is that from a 64bit cards > > (yup...if you ain't got 64bit PCI slots, you're not going to get anything > > better than ultra160) you travel over a fiber optic path to either a switch > > or a hub. Just like data networks a switch is a good idea if you have a > > multipath environment with multiple destinations....if you have but one > > server with one set of drives...then a switch is not necessary....a single > > HBA (fiber channel comes 1mb/sec or 2mb/sec) to an elcheapo hub to the jbod > > (just a bunch of disks) is pretty inexpensive and gives you the terrific > > throughput that folks like about sans. > > > > Now iscsi and such....same thing with a different name, different protocol > > with different amounts of overhead, etc....keep in mind that if you wanna > > play your storage over IP...that you're paying for the IP > > overhead....1gb/sec fiberchannel is faster than storage over Gig-ethernet > > due to overhead. > > > > Linux is supported well by qlogic and compaq is a relabeled qlogic card (may > > have changed...heard rumblings about emulex too).....interphase had great > > cards (gib+fiber channel) but I'm not sure they're around anymore???? > > > > I've run qlogic cards in solaris, linux and NT...they all work well....but a > > switch is necessary only if you're mixing several systems and have to carve > > up your array into several pieces.....but if only one system and one set of > > drives (can be multiple jbods) then a hub is fine. Emulex makes fine cards > > and hubs.... > > > > Oh yeah....most fiber channel doodads are LC fiber connectors over multimode > > fiber....those suckers are VERY expensive cables....you can also do sans > > over copper which is LOTS cheaper, just change the gbic....oh yeah, a > > gigabit ethernet SX fiber gbic is exactly the same at layer1 as fiber > > channel 1gig.....they are interchangable.... > > > > /brian chee > > > > University of Hawaii ICS Dept > > Advanced Network Computing Lab > > 1680 East West Road, POST rm 311 > > Honolulu, HI 96822 > > 808-956-5797 voice, 808-956-5175 fax > > > > _______________________________________________ > LUAU mailing list > [EMAIL PROTECTED] > http://videl.ics.hawaii.edu/mailman/listinfo/luau
