raid

[Guest JamesJ]

I notice this feature being available on some m'bords. Can someone tell me what this means please? JamesJ

[Guest MikePowell]

"RAID" stands for redundant array of inexpensive disks (or something close). It is a method of building a large, reliable data storage systems using multiple drives. There are several levels of RAID. Depending on what is implemented. a RAID system may offer higher average speed data access, and/or varying degrees of upgraded data reliability. Higher levels of RAID can offer complete data integrity even if a drive is totally destroyed.Mikewww.mikesflightdeck.comInfor for simpit builders.

[Guest]

What Mike said!The on board motherboards have RAID 0 & 1 capable IDE chipsets, giving you striping and mirroring, respectively.Raid0 = striping all information across multiple platters (drives). The OS will see one big virtual drive (ie. two 100gb drives = one 200gb drive). Advantage - fastest throughput to/from drive, most commonly used with streaming applications like video editing. Disadvantage - Zero redundancy. You loose a drive, all information is lost. Consider a backup strategy if your going to use this!RAID1 - Mirroring all information from one drive to another. The OS will only see one drive. Advantage - Good read performance using both drives, and if one drive fails, you'll be running off of the other. Disadvantage - twice the cost for the same space, writes take longer since the same information is written to two drives.Top of the line disk performance will come from a SCSI based system and third party controller (ie. Adaptec 3200S). Not sure about the IDE PCI cards out there, but the best IDE based RAID cards typically only approach the SCSI controllers in performance. But consider the cost difference between an IDE drive vs. SCSI.Is all of this worth it? Perhaps, if you can afford it and its worth the $$$ to you. Look for hardware sites that offer reviews on systems with such motherboards and/or RAID controller cards.Good luck,

[Guest artl]

>...>RAID1 - Mirroring all information from one drive to another. > The OS will only see one drive. > Advantage - Good read performance using both drives, and if >one drive fails, you'll be running off of the other. > Disadvantage - twice the cost for the same space, writes >take longer since the same information is written to two >drives. >>...>Is all of this worth it? Perhaps, if you can afford it and >its worth the $$$ to you. ...When compared to other backup methods, I believe a redundant drive is very convenient and economical, especially for big drives 120 gig and more (at least: against isolated hardware failure). For simming, you are doing mostly reads and few writes, anyway..., as long as you have sufficient real memory so there won't be any swapping. I operate in RAID-1 and have had one drive disappear for a short while (probably a loose plug), so was glad it wasn't RAID-0.I know that good statistics would be very hard to find, but multi-drive RAID-0 appears to be so-ooo dangerous. Anybody have any RAID-0 horror stories?? Art.

[Guest]

Boy do I! I used to do tech support for Adaptec, supporting all SCSI adapters, to include the AAA series and what was the DPT RAID adapters. When it comes to disasters, I've heard quite a few doozy's, many at the users own fault."I replaced what I thought was the bad drive and now my drive wont show up". Thats a classic, because in a RAID 1 or 5 config, you loose a second drive and the data's gone. If your lucky, and nothing has been written to update the RAID information on the RAID 5 set, you MIGHT get the set back into a degraded form by replacing the drive and still be able to 'save the ship' by replacing the actual bad-drive! Cross your fingers here folks.A big, and sometimes costly misconception about RAID is that it's thought of as "backup". Sure, in RAID 1 and 5 a drive could be lost and your safe, but what happens if something hicups or the adapter looses it's cookies? Everything can, and has been, lost!Near line or tape backup must accompany RAID. Sure most home systems may not need a tape backup system today, but in a year when their dual 80 or 120gb drives are reaching capacity with data that you really wouldn't want to loose (doc's, digital pictures, video, or music) tape will come in very handy.Tape prices are dropping in some areas. Personally, I like DLT, SDLT, or LTO, but they are very expensive when compared to DAT, AIT, and others. When it comes to tape, you pay for size and especially speed. Of course Ebay has about everything so shop around.Near line storage is another stop-gap fix, and may just be another hard disk in another system (read: Fileserver), NAS (like a Snap! server), etc. Still, the data is on a fixed drive that can fail. Tapes can be duplicated, archived, kept in a safety deposit box, etc. Sure, if you have small amounts of information, make CD's or DVD's, but considering we're talking about a RAID set...., just consider the time and effort it will take to recreate a Windows XP system, with all of your programs, Service Packs, program updates, AI Traffic additions, aircraft and scenery installations, etc. Just think of everything being on one or two tapes. Start the restore process and within a few hours, your back up and running with minimal effort.Hehe, you wanted a horror story? I worked for another company about 7-8 years ago who sold a 1/2 Terabyte SCSI RAID solution to a little company called C****x. They were nearing the end of a new build on there 'terminal server and client' software when we were called because the RAID set was down. Mind you, we're talking over 50 drives in this setup. So they flew me from CA down to FL and was there for about 4 days...it wasn't pretty. We figured out that not only did mulitple drives fail, but other 'good' drives had hard errors on the platters. If you don't know it, one drive with a "bad spot" on a platter will cause a "Rebuild" to fail, because the controller cant create good-data from garbage.I eventually had to low-level format each and every drive in the cabinet so that these hard errors would be mapped and unused, and of course, replace the bad drives. I left after data was being restored to the unit.They lost time and money because they couldn't get to their information to finish their code. They had the raw Windows NT 4 files on this box, which was enormous. Well, to finish the story, about a month later the entire RAID set suddenly ended up in our Receiving area with some ugly "we want our money back" documentation from some legal firm.Horror to the nth degree. Oh well, at least they did have a backup! :-)