RAID 1 Disk Configuration - Opinions, Please

[kjv1611]

Okay, I've not created and kept any RAID configurations to date at my home. I am considering changing my setup, with the purchase of a couple of hardware RAID cards, however.

Currently, I have this setup: (all SATA drives):
Windows/Program files on one 80 gig drive
"My Documents" on a second 80 gig drive
"Downloads, etc" on a 300 gig drive
Audio Recordings on a 200 gig drive

This is working okay, but I purchased some larger drives, as I was running out of storage space - pictures and videos of new baby, as well as audio recordings.

Also, my current motherboard, Gigabyte GN-7NNXP supports only 2 SATA devices, so I have an "add-on" card by Maxtor that I am using for the 2 larger drives. This card seems to have problems every other time I boot the machine - sometimes not recognizing one or both of the drives there - no RAID setup.

For data backup purposes, or data reduncancy (might fit the same purpose for me), I am considering one of the following setups:

Setup 1:
Windows and Program files installed on a RAID0 array (I'm not too concerned with protecting Windows and Program Files, as I can always just reinstall that stuff, and in a pinch, I can just use a separate older pc or laptop for anything that HAS to be done before system reinstall.
Either 2 RAID1 arrays or one RAID3 array (the RAID cards I have comming only support RAID 0, 1, 3). The disks used for this will be the new disks, namely 4 500 gigabyte hard drives.

Setup 2:
Windows and Program files installed in RAID0 array
4 separate 500 Gig hard drives, 2 for current data, and 2 to backup the initial 2. This is what has me thinking RAID1, possibly instead.

Setup 3:
Windows and Program files installed on a PATA 100 Gig hard drive. I am considering this, still, as my motherboard actually performs better in some circumstances with a PATA system hard drive, as apposed to SATA, as the SATA connectors are run through the PCI bus, anyway - which is where the add-on card(s) will be connected as well.
The 4 500 gig drives setup in either the RAID1 or JBOD configuration.

Setup 4:
Windows and Program files on one of the SATA 80 gig drives.
The 4 500 gig drives setup in either the RAID1 or JBOD configuration.

I do not plan on using all the available hard drives, as I would have to get REALLY creative to make all 9 hard drives to fit in the one full-tower chassis. I will have 3 or 4 DVD/CD burners installed - haven't decided for 100% sure, as I am replacing/changing some of those, and the case has a total of 5 3.5 inch drive bays if I remember correctly - I CAN just toss one or two others in there, and secure them, but I typically try to stay within the set contstraints of my case. I could purchase a larger case, but I prefer not to do so right now.

So, here is where I am uncertain, and would like some recommendations:

1. For the large disks (used to store data), I am considering having 4 separate disks - using 1 or 2 for backup, and the other 2 or 3 for live data. But, I thought, if I use RAID1, then the data will be mirrored in real time to both drives in each array. My only thought here is: if I decide to take one of those drives to a different system for whatever reason, does it have to be connected via the same RAID hardware in order to read the data?

I've read in a couple different locations about RAID 1 configurations being good for data redundancy. However, it sounded that if you have a RAID controller hardware problem, you would need to replace the RAID hardware in order to see the data. Is this true, or can you see the data the same, whether the disk is in the RAID 1 array, or taken out of the array, and used as a single disk?

Ultimately, I would like to do a RAID configuration, as well as a separate backup - but I don't want to spend the extra dogh for that just yet.

Alright, long post/question. Any opinions/advice will be greatly appreciated.


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"If to err is human, then I must be some kind of human!" -Me

 

[wahnula]

For data backup purposes, or data reduncancy (might fit the same purpose for me)

Redundancy and backup are two different critters. If your data gets corrupted then the redundancy is corrupt. Redundancy increases MTBF, backup is a must.

I would NOT ever consider JBOD. Zero benefits and fragile.

RAID3 is not used very often. I think you might be referring to RAID 5. Here's an excellent reference:

http://www.pcguide.com/ref/hdd/perf/raid/levels/tech.htm

I would use 2 of the smaller drives in a RAID 1 or 0 array for OS & apps, buy a decent card like a 3ware 9000 series (or Adaptec etc) and assemble a 3 or 4 disk RAID 5 array, and get a ginornous drive for external backup duties, spooling off DVDs of critical stuff as you go.

RAID drives ideally should all be the same size, make and model, but differing drives will work with the performance of the array dependent on the slowest drive.

Best of luck

Tony

 

[kjv1611]

Well, because of not wanting to spend any further funds than I've already spent - from the hardware mentioned in the initial post - I was thinking of using a RAID0 for the system, and a RAID1 setup for the 500gig hard drives.

I understand that a RAID setup does not protect against data corruption, but for my needs, I do not see an immediate need for that, necessarily. I'd be more concerned with the possibility of hardware failure.

However, thinking about that, I guess I could just use the disks as all separate hard drives (JBOD), and backup say the 2 primary to the 2 secondary, and just find a decent automated backup program that doesn't cost too much, which I could schedule to run daily or at least every couple days.

Thanks for the advice so far. And I do realize that backup and redundancy are not the same, yet for my purposes, if I don't care too much about whether the data gets corrupted, as much as I am concerned with possible hardware failure, I was thinking that the RAID1 configuration could be good enough to use - at least at first.

And I really did mean RAID3 - the cards I purchased do not support RAID5 (which is better), but they do support RAID3. Nonetheless, they were cheap and with good reviews.

I guess another option that I might could try would be this:

3 of the 500gig drives in a RAID3 setup - which would give me 1 terabyte of storage with some redundancy, AND use the 4th as only a backup drive. That wouldn't be enough to back everything up to, though, so I'm possibly leaning towards the other options. Of course, I may just end up keeping more of the hard drives than I originally intended, so that I have more options with all of this. I jsut need to make sure I have enough adapters/splitters for more SATA drives!


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"If to err is human, then I must be some kind of human!" -Me

 

[kjv1611]

One thing I spoke a little too quick on (because I forgot the difference in the specific RAID terms) is I mentioned using JBOD. I would tend to agree that JBOD is a bad way to go. I'd either do a RAID 1 or 3 configuration, or just leave them as "standard", basically 4 separate drives.

Any other opinions/ideas welcomed.

Thanks.

--

"If to err is human, then I must be some kind of human!" -Me

 

[wahnula]

I am considering changing my setup, with the purchase of a couple of hardware RAID cards, however.

That threw me off. I thought you were shopping for a new RAID card(s) and drives.

RAID 3 is OK, really quite good just not 'in fashion' like RAID 5 and the parity is not distributed, but fault tolerance is good.

If you have 500 GB drives at your disposal I would set up (3) 0r (4) IDENTICAL drives in a RAID 3 array, then use whatever's left for RAID 1 or 0 for OS & apps. The (2) 80GB should be fine. RAID 1 for safety, RAID 0 for speed.

After initially playing with RAID 0 & RAID 1, and multiple arrays, I have settled on one RAID 5 for everything WITH REGULAR BACKUPS to a 750 GB WD 7200.10.

My fastest drive is my backup! The way things are going it won't be long until I move that 750 into my RAID 5 array along with 2 others and get a 2TB backup drive (they will be along soon!)

Tony

 

[kjv1611]

With the way things are going, I'd not be shocked to see 2 Terabytes and lots more in the next year.

My main concern is this: If I use a RAID 3 or RAID 1 array, and I decide to do away with the RAID configuration, I would need to back the data up first, correct? Or, with a RAID 1 array, would that actually make it so that I would not HAVE to use the RAID setup in order to get my data back in the event of a system crash?

That's why I'm sure it's really best to just do RAID AND backup, but for now, I'm just trying to do one or the other, as it would mean spending additional funds on hardware to do both. In that case, I'd also be digging my own grave, because my wife would kill me - well, not really, I think.


--

"If to err is human, then I must be some kind of human!" -Me

 

[wahnula]

My main concern is this: If I use a RAID 3 or RAID 1 array, and I decide to do away with the RAID configuration, I would need to back the data up first, correct?

A RAID 1 member drive can operate as a single drive, with its status as a RAID array appearing as 'degraded' until you add the second drive back. Performance will not suffer, it should actually increase a tad. It's not neat but it works. Don't expect a RAID 1 member drive to be bootable as a single non-RAID drive.

If you construct a RAID 3 array you can remove any one drive, but with a severe performance penalty until it is replaced.

Should you construct a RAID 3 array and later want to move back to another type of storage, as long as you have a drive as large as the data in the array you can either backup/restore or my personal favorite, imaging (cloning).

There is much debate about imaging software, my choice is Ghost 2003 but both Acronis True Image and Drive Image have their fan bases. The point is to remove your data from one array and place it elsewhere (another array or single drive) it is always best to restore from a disk image if possible.

In the above RAID 1 scenario you could remove a drive from the array, connect as a non-RAID drive and then clone the 'degraded' image to the removed drive, remove the RAID drive and boot from the clone.

That's why I'm sure it's really best to just do RAID AND backup, but for now, I'm just trying to do one or the other

If you are new to RAID and the card is buggy go RAID 1 all the way, it is the safest choice with NO backup.

Tony

 

[kjv1611]

Thanks for the advice/info. That was my main concern - whether a RAID1 drive, since it is a mirrored drive, could be used in NON-RAID configuration as storage without changing any RAID info for the drive. Since it cannot, I think I'll go with RAID3. The card I'll use for that supports up to 5 hard drives, so the 4 drives should work just fine for that. Then I'll use a 3 connection card for the system RAID0. I may not see an improvement in boot times, but I think I'll end up seeing a little bit of performance boost for some applications - like audio editing.

I'll post back once I've found my Windows CD again, and have reworked my system. I wish I could get it done w/in the next couple of days, but it's more likely to be a week or two - mainly because I can't yet find my Windows CD! Argh!


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"If to err is human, then I must be some kind of human!" -Me