AutoDMC <3 RAID

[=[Ga]= AutoDMC]

One of my RAID drives just up and died.

But it's RAID 5.

So all my data is still there.

I <3 RAID

Just an ode to those engineers who spent all those years developing the RAID standard. This is to you, Mr. Slide Rule Man.

 

[Sn1PeR]

Raid 5 FTW! And when one of your drives dies you can hot swap a new sata drive in, the array rebuilds, no harm no foul, epic win.

 

[Deimos]

0+1 is where its at. speed+reliability

 

[Evil-Jester]

can some one please give me a run down on Raid and how it works the only one i know its raid 0 other then that its all a blank to me thanks

 

[Mr_Orange]

Raid 0 is striped. Data is striped across x number of drives resulting in an array with the capacity of XN where x is the capacity of the smallest of the drives and N is the number of drives. Cannot sustain a loss of any drives.
Raid 1 is Mirrored. The drives are identical to each other. Capacity is X. Can sustain the loss of a drives.
Raid 1+0 and 0+1 combines the first two. Requires an even number of drives greater than 4. The drives are then striped then mirrored or vice versa. Capacity is XN/2. Can sustain the loss of 2 drives as long as the two drives don't contain the same data stripes
Raid 3 is raid 0 with parity. The data is striped across all but one of the drives. The last drive essentially holds a compressed copy of tall the data on the other drives called parity. Can sustain the loss of a single drive.
Raid 5 is raid 3 except the parity data is distributed across all the drives. Can sustain the loss of one drive.
Raid 6 is dual parity. Like raid 5 except that the parity information exists twice. Can sustain the loss of 2 drives.

Those are the basics. RAID 0 gives the best performance but no redundancy. Raid 1 gives the best redundancy but no performance boost over a single drive. Raid 5 Gives a great balance of both. Raid 3 is nice for reads but is no faster than a single drive for writes.

If you want more info, I can go into greater detail about pros and cons as well as other raid types. Like RAID Z.

 

[Havegooda {A|R}]

Raid 0 is striped. Data is striped across x number of drives resulting in an array with the capacity of XN where x is the capacity of the smallest of the drives and N is the number of drives. Cannot sustain a loss of any drives.
Raid 1 is Mirrored. The drives are identical to each other. Capacity is X. Can sustain the loss of a drives.
Raid 1+0 and 0+1 combines the first two. Requires an even number of drives greater than 4. The drives are then striped then mirrored or vice versa. Capacity is XN/2. Can sustain the loss of 2 drives as long as the two drives don't contain the same data stripes
Raid 3 is raid 0 with parity. The data is striped across all but one of the drives. The last drive essentially holds a compressed copy of tall the data on the other drives called parity. Can sustain the loss of a single drive.
Raid 5 is raid 3 except the parity data is distributed across all the drives. Can sustain the loss of one drive.
Raid 6 is dual parity. Like raid 5 except that the parity information exists twice. Can sustain the loss of 2 drives.

Those are the basics. RAID 0 gives the best performance but no redundancy. Raid 1 gives the best redundancy but no performance boost over a single drive. Raid 5 Gives a great balance of both. Raid 3 is nice for reads but is no faster than a single drive for writes.

If you want more info, I can go into greater detail about pros and cons as well as other raid types. Like RAID Z.

Finally someone who knows (or I find out who knows) about RAID.

RAID5 FTW! You don't need uber write speeds and it's still faster than a single drive. Everyone says "RAID5 SUCKS"...well duh, of course it sucks...to RAID0. RAID0 is build for speed and speed alone. RAID5 isn't RAID0.

I'm going to be adding another two drives (for a total of six) to my RAID5 array once my new cable comes in

EDIT: RAID0+1 FTL (in my opinion). You only get the data storage capacity of two of your drives, but you do get a rather nice boost in read/write times...but it's not as if RAID5's times are terrible in the first place.

~Gooda~

 

[Ducttape]

RAID: Random Array of Inexpensive Disc

Considering the price of new hard drives (especially scsi's) I always laugh at 'inexpensive'

 

[Evil-Jester]

so for raid 5 you need 4 HD's or more? and ye pros and cons would be cool

 

[=[Ga]= AutoDMC]

RAID: Random Array of Inexpensive Disc

Considering the price of new hard drives (especially scsi's) I always laugh at 'inexpensive'

Well, from the datacenter point of view, a new SCSI drive is PEANUTS compared to some of the other "redundant" storage solutions out there... a couple hundred per gigabyte?

Other redundant systems require huge datacenter style equipment; RAID works with regular customer-quality drives and a special card.

And why are you looking for scuzzy drives? What is this, 1995? Or did you mean SATA? But even if you did mean scuzzy (For example, this $3/gb drive: http://www.newegg.com/Product/Product.aspx?Item=N82E16822332004), that's STILL cheaper in a RAID than many datacenter data redundancy systems!


NOW ON TO RAID

While the RAID drive has saved my butt, I'm thinking of breaking the array up. Of 4 drives, I have 3 good ones. I'm thinking of plugging one of those 500GB drives into the motherboard as my GAME drive, and using the other two into a RAID-0 for my projects (usually video rendering), and then replace the "R" with some kind of online backup service.

My "Hardware RAID" card turned out to be a "Hardware Assist" card, so most of the processing is done on the main CPU AND the card is crammed onto a PCI card... so maximum thoroughput to and from the array is ~100MB a second, on a good day, with no interference. Which is sad, as the array is 100% SATA 3.0Gb/s.

So, I still <3 RAID, I'm just not going to depend on the "R" bit, at least until I get a half decent controller

RAID Pros and Cons

RAID 0 PRO: Very fast and big (the size of both disks)
RAID 0 CON: If one disk fails, all your data is gone.

RAID 1 PRO: Decent speed and can survive a disk failure
RAID 1 CON: Small; only the size of one of the disks.

RAID 5 PRO: Plenty fast and big. Can survive a disk failure.
RAID 5 CON: Takes 3 disks, you only get the capacity of 2.

RAID 6 PRO: Even faster than 5, can survive two disk failures.
RAID 6 CON: Requires 4 disks, you only get the capacity of 2.

 

[Die Geheimwaffe]

RAID: Random Array of Inexpensive Disc

Considering the price of new hard drives (especially scsi's) I always laugh at 'inexpensive'

They changed the name to Redundant Array of Independent Disks getting rid of the questionable "inexpensive" part. Not sure where you got Random though

 

[RotaryVelocity]

thx god for RAID..made data recovery that much more easy