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mr.intel4_rules
02-20-2003, 10:05 AM
hey, i was wondering if someone can give me a full detailed answer to what RAID does. I see mobo now with raid 1 ,raid 0.wat does that mean???? and is raid good? how do i work with iT>???




: omg: :rofl: :rofl: :rofl:

kane2g
02-20-2003, 11:04 AM
Random? Array of Inexpensive Disks = RAID
basically what RAID does is allow one hdd to fail w.o loosing data. But you hook up ex 2 80gig drives and they are seen as 1 80gig drive in mode 0 or 1 (one is stripping the other mirroring)
Its good for fileservers and servers overall as the data stored is critical and cannot be lost.
Its mostly for the bussiness buyers, but some people (read me) want to have the option of RAID.
Im sure googling will get you more in-depth info, but thats basically it.
BTW there are 5or6 raid levels.

HTH

Beefy
02-20-2003, 11:35 AM
Close, but not quite.

Check out these threads:

http://forums.tweaktown.com/showthread.php?s=&threadid=3888

http://forums.tweaktown.com/showthread.php?s=&threadid=1837

Next time, have a look before asking.. ;)

kane2g
02-20-2003, 12:03 PM
its been a while, since i last looked into RAID, but i think its close enuf.
Too poor to get 2 drives, so i didnt play w. it yet.

Beefy
02-20-2003, 12:09 PM
What you described was RAID1 (mirroring). Basically having two duplicate drives. RAID 0 is a different setup.

mr.intel4_rules
02-20-2003, 01:04 PM
so,if i have 1 hd,will it effect my hd if i have RAID on my mobo?

mr.intel4_rules
02-20-2003, 01:11 PM
O,i get it,,so RAID 0 makes 2 HD to 1 like HD. ( 2 40 gb to 80gb)

but does RAID 1 do 2 HD,to like a same HD? (so if u save a file,the two HD will have the file??)


also,,will the cache be faster??

Beefy
02-21-2003, 07:10 AM
so,if i have 1 hd,will it effect my hd if i have RAID on my mobo?

RAID only works with multiple drives. Otherwise it's just a normal device.

RAID 1 (mirroring) simply creates two duplicate drives, so if one crashes you've still got your data. Not really much point unless you have very critical information you don't want to lose. Don't expect much (if any) of a performance increase using RAID1.

revenant
02-27-2003, 01:47 AM
Don't forget about RAID 0+1, and Raid 5. RAID 0+1 is a set of striped drives, which are mirrored! Super fast, and fully redundant. You need a minimum of 4 drives of equal geometry (any time you mirror, you want to use drives with the same geometry) for that, you stripe 2 of them, then that stripe is duplicated on the other two. I'm using this method now and it's wicked fast. Reads and writes are done across all of the disks at the same time, you can make the obvious conclusion that it'll be a LOT faster than just a single drive. RAID 5, less popular in the IDE world, but very popular on big storage systems like Network Appliance and EMC, is a little different. It involes a minimum of 3 disks of equal geometry, two of them are for data, and one is for parity. This method is not as performance oriented, but you get the largest amount of storage out of your disks that you can will full redundancy. You always have 1 drive for parity with RAID 5, thus, in a 10 drive RAID 5 array, you would have the storage capacity of 9 of those drives. You can also add a "hot spare" with some RAID controllers wich will kick in if a drive fails. This is good because when a drive does fail with RAID 5, the performace is very bad running with no parity disk, and if you loose another driver before you can replace the dead one (not likely, but possible) you are DONE! That's what is sooooo dangerous about RAID 1 (just striping). If you loose even one drive the whole array is worthless, and all your data is lost. I had this happen to me once, and I will never use that again. I know Promise makes a RAID 5 capable IDE RAID controller, it's around 150 bones. But with the price of drives these days, making a RAID 0+1 array is quite doable, even on a budget. My $0.02

:cheers:

Beefy
02-27-2003, 05:00 AM
I think we covered that in one of the other threads too. :) But well said.

However, one thing about RAID 1. When you lose 1 drive, yes, you do lose it all. BUT... Imagine this. We have two setups.. one with a 120GB drive, one with 2 x 60GB drives in RAID 1. OK. Now, in each setup, you lose 1 drive due to failure. In both cases, you will lose 120GB of data. However, for replacement factors, you only need to replace a cheaper 60GB drive in the RAID, whereas in the other you need to replace a 120GB drive. Not cheap. Also, while you are getting your new drive for the RAID, you can temporarily set up the remaining drive and run off that.

Not as bad as it seems...

FLaCo
02-27-2003, 06:11 AM
Good point beefy...i always mention that to buddies that doubt RAID...because of the cost.

revenant
02-27-2003, 08:11 AM
Yes, very good point Beefy. But, again, you double your chance for disk failure with two drives. :) (sorry for the over-statement, just wandered into this forum today for the first time and this was the first thread I went into :))

Beefy
02-27-2003, 09:29 AM
touche.... :) Good pick up there...

This is just gonna teeter back and forth I think. Both options have pros and cons, so you've basically got to decide which way you want to go....

revenant
02-27-2003, 01:35 PM
:cheers:

kane2g
03-18-2003, 04:07 PM
here's a link that sums it all up
http://www.tyan.com/support/html/r_levels.html