Raid....Hard drives need to be exactly identical?

[TheCorm]

Do you need to use exactly identical hard drives or would using a 30gb 7200rpm Maxtor and a 30gb 7200rpm IBM be okay?

Also, can you have partitions within raid or does it need to be a single logical drive?

Cheers,

Corm

 

[Alphazero]

The hard drives do not have to be identical. They don't even have to be the same size (but you'll waste space that way).

Once the array is set up, it is seen as a regular drive, which can be partitioned any way you like it.

 

[TheCorm]

Excellent....info right on the nail.

Cheers,

Corm

 

[MichaelD]

The whole reason for striping two drives in a RAID 0 stripe is to obtain optimum performance, right? Right.

For optimum performance, both drives should be the exact same model and size. I.E. Two Maxtor 7200rpm DM+ 40GB drives.

You will probably be OK, mixing the IBM and the Maxtor...what are the seek times on both drives. Hopefully they are close.

Don't ever mix a 7200 and a 5400rpm drive...you'll be lucky if it works at all...I mean, it'll work, but speeds will probably be slower than a single drive.

If you mix two 7200 rpm drives of different capacities, your overall drive size will be 2x the size of the smallest drive.

Also, when setting up your stripe size in the Raid controller's BiOS, pick the biggest stripe size you can. I use 64kb.

 

[TheCorm]

If you mix two 7200 rpm drives of different capacities, your overall drive size will be 2x the size of the smallest drive

How does this work, I thought that if you put two identical 60GB drives together in raid you get 60GB capacity?.....so if you put a 30GB and a 60GB you would just have 30GB with 60GB wasted on the larger drive.

What I am probably going to do now that I know I can partition is get another 60GB ATA133 Maxtor as the Raid card is ATA133 too and then have the 30GB IBM on the primary IDE channel.

Corm

 

[Alphazero]

If you put the two 30GB drives together in RAID 0 you will have a 60GB array. If you use a 60GB drive and a 30GB drive, you will still have 2x30 = 60GB.

 

[TheCorm]

Ah...so if it's striped then you get the capacity of the smallest drive x2 but if it's mirrored then you get the capacity of the smallest drive x1?

 

[joeryu]

Originally posted by: TheCorm
Ah...so if it's striped then you get the capacity of the smallest drive x2 but if it's mirrored then you get the capacity of the smallest drive x1?

you are correct

 

[MikeMike]

nope no where near the same size

mine are wd 120gb 7200
and
maxtor 80gb 7200
raid 0 i dont need the 40 gb i lost, and if i do it wont be till later

 

[yhdd]

Originally posted by: nourdmrolNMT1
nope no where near the same size

mine are wd 120gb 7200
and
maxtor 80gb 7200
raid 0 i dont need the 40 gb i lost, and if i do it wont be till later

thats dumb....u just wastin 40gb

 

[Goi]

RAID 0 isn't even truly RAID at all, since there's no data redundancy. Many would recommend against it as you double the chances of disk failure. RAID 1 and RAID 0+1 are much wiser choices.

 

[MichaelD]

Originally posted by: Goi
RAID 0 isn't even truly RAID at all, since there's no data redundancy. Many would recommend against it as you double the chances of disk failure. RAID 1 and RAID 0+1 are much wiser choices.

Bah! You're right about the "not really RAID" part. But AFA the dependability goes, today's HDs' (with the exception of the IBM Deathstars, of course) are way reliable as long as you do the maintenance on the array, you'll be OK. I.E. getting rid of things like temp internet files and defragging once a month or so.

I have had a two-drive stripe going since February...mostly running 24/7. I have had no data corruption or crashes.

However, I have backups of all the "crucial" files. I.E. drivers, service packs, address book, emails, My Documents...things like that.

Go for the stripe!

 

[Goi]

Well, wait till you get a data corruption/error, then you'll be cursing and swearing at RAID 0. Its better to be safe than sorry. Its the same thing with virii, once bitten twice shy.

 

[chiron]

I agree with the redundancy issue; I'm making a new system myself, and after having multiple problems over the last couple of years with win2k corruption issues, I've decided to run 1x Maxtor 40GB ATA133 on the primary IDE channel, and 2x Maxtor 60GB ATA133 on RAID1 (mirroring). At least it should help when/if the eeevil M$ software decides to die again

 

[TheCorm]

To run Raid 0+1 do you need 4 hard drives?

Corm

 

[Goi]

That's the minimum The Corm...

 

[TheCorm]

Another question (sorry!).....If you used 4x60GB hard drives in a raid 0+1 would that give you 120GB of storage space?

Corm

 

[chiron]

yes

 

[ScrewFace]

Stay away from RAID. You don't need it with today's screaming fast hard-drives.

 

[TheCorm]

Is that a wide concensous....I thought raid was still popular.

 

[Sunner]

I agree with ScrewFace(nice name, really), if your only reason for going RAID is performance, don't.
Or if you're really serious, go RAID 1+0, but going plain RAID 0 is stupid for general purpose usage IMO, you'll effectively double your chances of having a failure wipe out all your data, and the performance gain is unlikely to be something to write home about outside of benchmarks.

You'll increase your transfer rates, but your access times will likely increase, though very slightly, but in the end, access time is often more important than STR, which is why 15K RPM SCSI drives keep crushing even the fastest ATA drives, even though the ATA drives can often match or even beat the SCSI drives in STR performance.

 

[chiron]

RAID is still popular - perhaps not so much as far as the performance aspects go, but definately for the redundancy. TheCorm, by that, I mean RAID1 uses 2 drives, with mirrored data. So if drive(x) fails, drive(y) will be an exact copy, will boot/use data from that drive instead, and inform you that a drive has failed.

Sure, there's no performance gain for the money spent, but how valuable is your data? I've got too much stuff to burn onto cds all the time, and I'm not going to get a DVD burner until a standard is settled (even though I sell the burners at work )

 

[TheCorm]

Well....striping is looking less attractive....mirrored is looking tempting.

But what I am also considering doing is putting in a removable hard drive bay and having a 30GB 5400rpm drive to do backups onto.

For this I would need another IDE connector so am consdiering an ATA133 Raid card and just use the ports on it as standard IDE connectors, theres no probs with that I presume?....an eventually I can get myself another 30GB disk and alternate them for backing up!

Corm