Advice on new proposed RAID setup..

[techguy101]

Hi Guys,

I currently have two 1TB drives being mirrored with Robocopy. While it does the job it's beginning to piss me off..

I was thinking of buying this card
http://www.lindy.ie/shop/showProductDetail.do?orderNumber=51150

I have a spare (brand new) external Iomega Prestige 2TB drive here. I was thinking of taking that out and buying another 2TB to mirror it with.

I have seen some 5900 drives that are good value. Could I use one of these? Can I mix speeds(rpm) in the RAID 1 array?

I'm thinking I won't be sacrificing too much speed due to the lower rpm. This is becuase RAID 1 provides higher read/write performance anyway.

Thanks in advance for any thoughts..

 

[Old Hippie]

This is becuase RAID 1 provides higher read/write performance anyway.

You sure you're not thinking about RAID0?

RAID1 is just mirroring another drive and will do nothing for performance.

What are your goals for this RAID array?

Have you read the "RAID is not a back-up" thread?

 

[techguy101]

My bad,

There's only a read benefit on RAID1 no write benefit.

The array is just for my desktop development machine. I just want some redunancy so that if a drive fails I can still work away.

I will have offsite (online) backups of my project work and I periodically archive projects to DVD.

Am I approaching this the right way?

 

[Old Hippie]

There's only a read benefit on RAID1 no write benefit.

AFAIK there's no performance increase with RAID1.

AAR, mechanical redundancy is RAID1.

You can mix any drives you want but the array will take all of the performance and space values of the lowest performing/smallest drive in the array.

RAID1 can be done on most MB chipsets without an extra card.

 

[tormentum]

Yes, this card will do the trick for you, however you'll need to be careful when moving from your on-board SATA to the RAID sata.

Also, is the system you're wanting to do this on the one you have referenced in your signature? If so, the "Abit IP35 Pro" has onboard RAID. Usually the on board solutions work fine for RAID0 or RAID1. I'd never use an onboard RAID5 though.

http://www.abit.com.tw/page/en/motherboard/motherboard_detail.php?pMODEL_NAME=IP35+Pro&fMTYPE=LGA775

Oh, and it's generally recommended to use identical drives in a RAID config. This makes neither drive a bottle neck as both are identical speed (amongst other factors)

 

[techguy101]

AAR, mechanical redundancy is RAID1.

Huh?

RAID1 can be done on most MB chipsets without an extra card.

Yea, I know, I have an ABIT IP35PRO that has the Intel ICH9R chip but I can't for the life of me get RAID1 to work.

I tried lot's of things, but when I "successfully" build the array it tells me that one of the drives is a "non-raid-disk".. I even had the shop replace the drive, thinking it was faulty.

I'm just putting it down to a faulty chip or something. Is that just silly?

Yes, this card will do the trick for you, however you'll need to be careful when moving from your on-board SATA to the RAID sata.

What should I be careful of? I'm building a new server at the moment and plan on moving all my data over to that while I work on this machine.

Also, is the system you're wanting to do this on the one you have referenced in your signature? If so, the "Abit IP35 Pro" has onboard RAID. Usually the on board solutions work fine for RAID0 or RAID1. I'd never use an onboard RAID5 though.

Yes, it is. See above..

Oh, and it's generally recommended to use identical drives in a RAID config. This makes neither drive a bottle neck as both are identical speed (amongst other factors)

I figured as much. But the one 2TB drive is coming out of an external so I won't be able to match them unfortunately.

Speeds etc don't really bother me because it's just a storage drive for my projects/movies.
I have an SSD for the OS.

How bad would the bottleneck be? I'd say just marginal?

 

[tormentum]

i'd be surprised if the chip was faulty, you'd probably be having other issues as well. Make sure you're using the latest driver from the intel site: http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=18859&ProdId=2101&lang=eng

You can configure your RAID disk either from the RAID BIOS (during system post stage), or using the Intel Matrix Storage Manger.

Is the disk you're trying to RAID your system drive, or a secondary data drive?

 

[tormentum]

Oh, and if it's your system disk, you'll need to take a disk image (eg: Ghost, Acronis, Clonezilla), create the RAID mirror, and then restore the backup onto the new RAID volume. This is due to the fact that ICH9R will destroy your current partition table and the like, rendering current data in-accessible.

It's a little more involved, but worth it for the redundancy.

 

[Old Hippie]

I tried lot's of things, but when I "successfully" build the array it tells me that one of the drives is a "non-raid-disk"..

I have no idea what that means but I've had an IP35-Pro and my ran RAID just fine.

How 'bout trying to set-up a RAID0 array and see if it acts the same way?

You do have the Intel RAID drivers loaded, set the BIOS to RAID, and then create the array after Ctrl + I .....correct?

If you're trying to create a RAID1 array with data already on one disk, I dunno how that would work.

 

[techguy101]

It's a secondary drive.

How do I go about installing the newer drivers? Just through windows or do I need to anything extra?

Will I need to slipstream those drivers when installing Win7 or do they come included?

 

[Old Hippie]

Oh, and if it's your system disk, you'll need to take a disk image (eg: Ghost, Acronis, Clonezilla), create the RAID mirror, and then restore the backup onto the new RAID volume.

Yes, if the OP is trying to expand an OS to RAID1 that may be the reason for the error.

If it were me, I'd do a reinstall.

 

[tormentum]

You don't need to slipstream the driver, no. During Windows 7 setup, it will ask which disk you want to install on. You can also specify a storage driver at this time. Have the driver available on a USB memory stick.

 

[Old Hippie]

Will I need to slipstream those drivers when installing Win7 or do they come included?

Yes they are included in W7....just make sure to install W7 in RAID mode and do the install.

 

[john4200]

AFAIK there's no performance increase with RAID1.

There can be, but only on reads, as he said when he corrected his original statement. Not all RAID 1 systems implement it, but it is a simple matter of reading alternate chunks from each drive in the RAID 1. You can get nearly double the sequential read speed of a single drive that way. Also, random reads can be sped up by getting both drives seeking in parallel.

 

[Red Falcon]

There can be, but only on reads, as he said when he corrected his original statement. Not all RAID 1 systems implement it, but it is a simple matter of reading alternate chunks from each drive in the RAID 1. You can get nearly double the sequential read speed of a single drive that way. Also, random reads can be sped up by getting both drives seeking in parallel.

You can get increased read speeds from this, you are right. I believe it is called RAID 1.5, but I'm not sure exactly how to implement it. I know there is a wiki article on it somewhere.

 

[Old Hippie]

There can be, but only on reads, as he said when he corrected his original statement. Not all RAID 1 systems implement it, but it is a simple matter of reading alternate chunks from each drive in the RAID 1.

I can accept that but it's not a normal RAID1 and will probably only confuse many that aren't familiar with RAID arrays.

 

[techguy101]

Why isn't it a normal RAID1?

Because the drives will spin at different speeds?

 

[Old Hippie]

Why isn't it a normal RAID1?

Because the drives will spin at different speeds?

I wasn't referrign to your set-up.

Normal RAID1 doesn't increase any speeds but there may be a version that increases read speed, RAID1.5.

It's got nothing to do with your set-up.

 

[Old Hippie]

and will probably only confuse many that aren't familiar with RAID arrays.

Why isn't it a normal RAID1?

Because the drives will spin at different speeds?

I rest my case.

 

[techguy101]

I rest my case.

I would have thought the standard implementation of RAID 1 would give read speeds performance increases to a factor of nX (where n = number of drives) because once written the data is on all the drives..

Anyway.. will it really be that bad if the two speeds are different?

 

[Old Hippie]

I would have thought the standard implementation of RAID 1 would give read speeds performance increases to a factor of nX (where n = number of drives) because once written the data is on all the drives..

Sorry, no.

You want increased reads/writes go with RAID0.

Anyway.. will it really be that bad if the two speeds are different?

You can mix any drives you want but the array will take all of the performance and space values of the lowest performing/smallest drive in the array.

I would not use a Green (slow) drive for booting.

 

[techguy101]

Sorry, no./QUOTE]
Why am I reading all over the web that RAID 1 can give increased read speeds?

You want increased reads/writes go with RAID0.

I'm not looking for increased read/write speeds.

I would not use a Green (slow) drive for booting.

Who said anything about a green drive or booting?

I'm using an SSD for windows..!

The RAID array is for archiving data and storing project work.

 

[Old Hippie]

Sorry Bud.

I guess I'm trying to help to many people at the same time and it's all getting too confusing.

I'm sure someone else can help you with this.

 

[techguy101]

I think you confused the whole thread and everybody reading..

I was originally just asking peoples opinions on mixing two hard drives of different rotational speeds into a RAID 1 array.

I'm quite familiar with the different levels of raid and how each one operates.

 

[drescherjm]

Why am I reading all over the web that RAID 1 can give increased read speeds?

Theoretically it can but it depends on whether the implementation supports this feature. Most fakeraid will not and also I would expect windows software raid to not have this feature.

 

[john4200]

I can accept that but it's not a normal RAID1 and will probably only confuse many that aren't familiar with RAID arrays.

Actually, it is normal RAID 1, if by normal RAID 1 you mean a mirror, with 2 or more identical drives. I am not talking about any special RAID format (Red Falcon, RAID 1.5? You're nuts! )

Just think about it. You have identical data on both drives. If you need to do a 1GB sequential read, you might divide it into 1MB pieces, and read the first MB from the first disk, the second MB from the second disk, third from the first disk, and so on. But doing it in parallel gets you nearly twice the transfer rate. If it is done right. You'd actually want to try to choose the I/O size to minimize rotational latency as you "skip" to the next read. But even without that, you can get a big performance boost if you use large transfers.

Also, as I mentioned before, it can speed up your random reads. By distributing the reads among the drives, you can nearly double your IOPS.

But only a few RAID1 systems are sophisticated enough to take advantage of it. Areca for example. All of them COULD do it, though, if they were programmed that way.