I have a Raid1 off the mobo (firmware raid) on my current desktop, with 2 250gb matched drives. Im thinking of putting in at least one more drive and making it a raid5.

Pros:
better use of all storage-500gb vs 250
data redundancy (yes I know there are limitations here, I dont wanna discuss it, unless tis a comparison beween raid 1 and 5)
Minor speed increase

Cons:
with 3, no proactive redundancy
I cant pull one and use it as is (i can do this now with my current raid 1 setup, and have before)

Also, Ive always heard use matched drives with raid, any thoughts on this? I may change brands, and also possibly sizes (I know ill lose a bit on the size if i do go this route). Also might change cache size.

7/21/2009 1:59:13 PM

I use a software based RAID5 within Windows XP across 4 1TB Samsung hard drives.

It freaks out every so often, but I've never lost any data over the past like 5 months and it's not what I would consider fast, but it gets the job done.

In my opinion, given how dirt cheap hard drives are, it'd be silly to RAID5 something as small as 250s.

7/21/2009 2:10:50 PM

do you need constant data backup?

why not just run a single drive with an external backup? cheapest and fastest option.

7/21/2009 3:11:41 PM

I would buy a perc raid card off ebay for $100 for hardware raid.
like these
http://cgi.ebay.com/Dell-Perc-5i-PCI-Ex8-SAS-RAID-Controller-w-512M-card_W0QQitemZ380134247306QQcmdZViewItemQQptZCOMP_EN_Networking_Components?hash=item5881c44b8a&_trksid=p3286.c0.m14&_trkparms=65%3A12|66%3A2|39%3A1|72%3A1205|293%3A1|294%3A50

then you get a real speed increase and you sort of have proactive redundancy as the memory cache buffers reads/writes and checks crc

7/21/2009 3:16:09 PM

If you want to see the performance from the PERC card mentioned abouve see this thread
http://www.overclock.net/hard-drives-storage/359025-perc-5-i-raid-card-tips.html

7/21/2009 3:51:11 PM

OK let me make it clear:

I dont want to hear anything about data back up. I know the rules.I follow most of them.

Im also not looking for other solutions other than what I have. Im only asking opinions on going from raid 1 to raid 5 with what I have, with possibly mismatched drives.

Stein, Im not looking for anything really fast, eg velociraptor fast, just I know it has its perks, not really needed though but welcome.

7/21/2009 4:18:21 PM

Sorry, let me clarify -- when I say it's not fast, I mean it actually seems fairly slow. I haven't done any read/write tests to determine actual speed, but I know that most file write operations on the drive seem to take longer than on individual drives I have (which makes sense, I suppose). I only do reads when I do video playback, and it's fast enough for that.

I'm guessing you're going the software based route as well, in which case I should mention that having different drives shouldn't matter. Keep in mind though that you'll have to destroy your current RAID array in order to build the new one. You can't (as far as I know), jump right from RAID1 to RAID5.

[Edited on July 21, 2009 at 4:46 PM. Reason : .]

7/21/2009 4:45:35 PM

I start with the premise to get to the best solution. Just because people ask questions doesn't mean they are asking the right question, what I posted was NOT irrelevant, I was merely asking you a question at what your main purpose was for your RAID setup in order to give you an appropriate response. Just saying, "hey i want to add more drives to my raid setup, which raid should i do" isn't enough information. Redundancy and backup are two different things.

Quote :

"Ive always heard use matched drives with raid, any thoughts on this?"

depends on which RAID, RAID 1, YES, absolutely use matched drives, in the case of RAID 0 you can throw any size hard drive, any brand so long they are on the same interface. for RAID 5 though it's best they are at least the same size, preferably matched.

if you have software RAID, you're best option may be to buy two new drives and do RAID 0+1, stripe one of the older drives to the newer drive, then mirror. You get redundancy & speed. Again though it would benefit you to have new drives that are same size and nearly identical as possible.

[Edited on July 21, 2009 at 4:52 PM. Reason : .]

7/21/2009 4:47:58 PM

^ & ^^ my apologies to you both. You are both correct. Prospero, I meant, that you interpreted, I dont want a hardware raid solution. And yes data redundancy and backups are different.

Stein Ive never done speed tests either. I have the OS on the RAID and most of my games and my VMware servers on a spare drive also in the system but not RAIDed. I notice no diff between doing OS related or anything on the RAID vs gaming or anything with VM (VM does have issues with RAM but thats another story)

Also its firmware, not software. There is a diff. Mobo RAID is firmware. Then also there is proper hardware raid. Firmware is like software in that it uses the CPU to do the work, but it has hardware support in I believe the southbridge chip to assist.

Prospero, while everything is backed up externally, I like having a "redundant backup" as well as 'redundantcy' on the machine itself, both for day to day issues as well as a secondary main backup for the normal stuff you want backed up. Thats why its in a RAID 1 vs a 0. Constant backup I dont care about but its useful.

Base rules with raid is that you want to use matched or at least same size drives, you can get mismatched including sizes to work, it just takes on the smallest size drive. Some software raids ive seen for raid 0 actually will accomplish a raid 0 on a single drive through partitioning. least thats what ive heard. never tried mismatched drives, only reason i would is I can get 320s for same as 250s.

Im not sure if I can do 0+1, and Id think id rather do 1+0 (not sure if possible as well), as its more redundant, and speed really isnt an issue here, its just a plus. I know I can do raid 5.

7/21/2009 5:30:56 PM