How To break apart a Raid Setup? HELP!
 

Hello everyone...

We have a hi-end Dell editing station that is 1 gig and set up as a Raid 5.

Is there an easy/efficient way to break-apart the Raid and just use the system as 4 individual hard-drives?

Each at 250 gig per?

The Raid 5 is just slowing the system down really badly.

Any help is greatly appreciated...

And Kind Regards...

you can't break the raid 5 without losing the data on the drives. you'll have to backup the data first and then reinstall the OS and then restore the backup.

yup, no choice....

Can I change it over to a Raid 0?
for speed?

Would this be easy to do?

Is Raid 0 truly reliable?

Thanks

{{{day time bump}}}


Anyone?

short anwser: no
long answes: you'll lose all data when you change the raid type :)
best way: backup the data..
break the raid.. setup as 4 seperate drives..
restore data

Understood.


With that said...

Do you have any tips or ideas on how to make this Raid 5 work faster?
It seems like things come up slow and the hard-drives are always working.

This is a Dual Xeon 3.4 gig
2 gig rams
1 terrabyte raid 5 (4 250's)

Please advise on any suggestions

THANKS!

--anyone---anyone---... ?

RAID0 isn't reliable at all because there's no redundancy... a single failure will render the array unusable. If it's just used as capture+scratch space then this isn't such an issue, although the PC will not be able to boot with a failed array.

If it's used for transient data then perhaps consider the OS+perm data on a single drive, then a 3 drive RAID0 array.

BTW, 4 x 250GB on RAID5 is actually 750GB useable... you lose 250Gb to redundancy parity.

Oh yeah, is it software RAID? That could explain why it's slow... the parity calculations for every byte of data written are done by the PC CPU rather than a dedicated chip on the RAID card.

Rowan,

thanks for the reply... It is a dedicated Raid card.... on a Dell Precision Workstation 670.

Have you tried defragging? Even a RAID will need to do that. I'm using RAID 1 and have never had any trouble with the speed. If you have the funding, you could always go to 10K raptor drives. Still, try the defrag if you haven't already.

Even some RAID cards these days are little more than a HD controller with some extra features in the startup BIOS, with the "in-OS" driver software doing the rest.

The RAID card is an Adaptec CERC SATA1.5/6ch

Is that a good one?

If your problem is speed I would recommend a RAID 10 but you would need more hard drives and to copy all the data off your current RAID 5 to do that. I would imagine that you probably need a new raid controller, something with a cache and processor on it. http://www.newegg.com

Brad

RAID 0 is a recipe for disaster. If you have 4 drives in RAID0 you are four times as likely to lose your data than if you use a single drive.

RAID1 (mirroring) is the fastest option, if you have four drives then RAID 10 is the fastest and safest. - you do lose half the capacity of the drives though.

From a quick web search this appears to be a software RAID card. Does it say "HostRAID" anywhere?

There's nothing absolutely horrible about software RAID... it's just not as fast as doing it in hardware, and it may not be supported by alternative operating systems. I have an Intel software SATA1 RAID setup (1+0) under XP SP2 which has an average read speed of 150MB+/sec.

As darling2 suggested, RAID10 (aka RAID 1+0) will probably give you the best performance overall as it is both striped (faster) and mirrored (redundant). The downside is that out of 4 x 250GB drives the array capacity will only be 500GB (half of the total). The next best would probably be RAID5.

RAID0 is not redundant at all.

The CERC Raid card is a hardware Raid-5 card with 6 channels. There should be a web based app that you use to manage the card and to run diagnostics.

Things to check for performance issues.

1. What is the cache on the drive: 2mb, 8mb, 16mb?
2. What is the speed: SATA, SATA2-150, or SATA300 ?
3. What speed is the card rated at?
4. Do you have a failed drive in the array?
5. Is the BIOS of the drives up to date?
6. Is the BIOS of the card up to date?
7. Are the RAID drivers in the OS up to date?
8. In the task manager, show one graph per CPU. Is any one CPU maxed out?
9. Try disabling services and programs to see if you get a sudden performance boost.

The way the CERC works is that it creates a virtual pool of space that is composed of whatever space from the multiple drives that you assign. When you set up a drive letter you are actually creating a virtual drive that is carved out of the pool.

David.

raid 5 blows i hate it

i just mirror with hotswap spares ready to go