Intel raid: ICH10R and adding drives to a raid 5

[LxMxFxD4]

Hey guys,

newegg JUST sold out of the $120 hitachi 2TB drives.. boo. Actually, I bought the last 2 they had. I needed 4. Now I have a question:

I have an ICH10R raid controller which so far as has been really great for my needs in a raid 5. But I need to upgrade the drives as 900GB array isn't enough.

If I build the raid 5 with 2 drives can I just add drives later to expand the capacity and when I do so it will just rebuild the array?

Reason I ask is I saw this on intel's website:

Building or buying a PC with a single Serial ATA hard drive, then upgrading to RAID at a later date is typically not a simple task, as it requires the reinstallation of the OS and applications. However, an Intel Express chipset with Intel Matrix Storage Technology** can be more easily upgraded to RAID capabilities when adding one or more additional Serial ATA hard drive(s). The Intel® Matrix Storage Manager software (included with platforms supporting Intel Matrix Storage Technology) handles the configuration and migration while running in the background, allowing users to surf the Web or read e-mail during the process. Once the migration is complete, dramatic increases in data protection or storage performance are available.

I wouldn't ordinarily think so but that makes me think its possible?

 

[Emulex]

get a CERC or Areca man. one with battery back write cache. I hope you got the Enteprise hitachi (starts with E part #).


or setup a solaris file server with that nifty raid-5 like they got going on. from what i've read it is far superior to matrix raid - RAID HOLES.

I'd just do raid-10 honestly. cost of drives are so cheap these days

 

[LxMxFxD4]

get a CERC or Areca man. one with battery back write cache. I hope you got the Enteprise hitachi (starts with E part #).


or setup a solaris file server with that nifty raid-5 like they got going on. from what i've read it is far superior to matrix raid - RAID HOLES.

I'd just do raid-10 honestly. cost of drives are so cheap these days

I just got the cheapo $120 2TB drives. As for raid5 vs 10, I really dont need any sort of performance outta the thing - I just need my data safe. I currently have 4 300GB maxtors that are almost 5 years old.. not a single drive failure in that time, im highly impressed.

Anyone got an answer to my original question though?

 

[Emulex]

well the reason i didn't answer it is because you can't build RAID-5 with 2 drives.

and intel matrix raid does not support raid level migration which is what you maybe mean. build with raid-1 then migrate to raid-5 in background. Very common with a REAL raid controller.

by the way - sorry if i came off snarky but i'd say those 300gb drives - yeah i remember those - bulletproof - let me inject this: Drives today are not built the same as they used to.

I've got 4gb,9gb scsi, 4gb ATA (yes the old seagate) 200-250-320gb seagate - rocking out like champs - the only drives that i've had fail are the newer high density ie 1TB,750gb, 1.5TB,2TB). do not expect to get the same life expectancy. it sadly isn't there.

Which is why i recommended the E-series hitachi with a real raid controller.

 

[LxMxFxD4]

well the reason i didn't answer it is because you can't build RAID-5 with 2 drives.

and intel matrix raid does not support raid level migration which is what you maybe mean. build with raid-1 then migrate to raid-5 in background. Very common with a REAL raid controller.

by the way - sorry if i came off snarky but i'd say those 300gb drives - yeah i remember those - bulletproof - let me inject this: Drives today are not built the same as they used to.

I've got 4gb,9gb scsi, 4gb ATA (yes the old seagate) 200-250-320gb seagate - rocking out like champs - the only drives that i've had fail are the newer high density ie 1TB,750gb, 1.5TB,2TB). do not expect to get the same life expectancy. it sadly isn't there.

Which is why i recommended the E-series hitachi with a real raid controller.

Didn't think you were snarky at all. The intel controller is just the poor man's solution. Thanks for answering my question and I forgot you have to have a min of 3 drives in raid5. Looks like I'll have to bite the bullet and pay $140 per drive somewhere else.

As for life expectancy - I REALLY expect to replace entire arrays every 5 years so this is just crazy unexpected. Do you happen to have any links to where MTBF is so much higher on these new drives? I mean that seems odd.. but then I dont read reviews every day like I used to either...

So jsut to be be sure - Cannot add drives to a raid5 to increase the capacity on an intel ICH10R? Can you do this on ANY raid controller??

 

[Nothinman]

So jsut to be be sure - Cannot add drives to a raid5 to increase the capacity on an intel ICH10R? Can you do this on ANY raid controller??

It might be possible to add a 4th drive if you already had 3 drives to build the array with, but I doubt it'll let you build the array in a degraded state like you could get away with Linux software RAID.

 

[Emulex]

i think you better have a damn good backup system in place.

1. simulate a power outage once you've loaded it up with data (raid-5) - it's going to happen
2. all real raid controllers have battery (or flash) backed write cache. This usually is required to do online migration (raid expansion, shrink, stripe size change, conversion).

alot of people do raid-10 then realize they need more space so they do online conversion from raid-10 to raid-5 which leaves them with spare drives unused. then they do raid expansion to use up the new drives. Then with windows server 2008 you can do online partition expansion (2003 didn't have this iirc).

 

[Emulex]

i do stripe size conversion to optimize for application all the time.

 

[LxMxFxD4]

It might be possible to add a 4th drive if you already had 3 drives to build the array with, but I doubt it'll let you build the array in a degraded state like you could get away with Linux software RAID.

Yeah, my question is really - can I build the array with 3 drives and then add a 4th later and rebuild the array at that time?

 

[retnuh]

Usually you can grow a raid 5 array when adding drives. But with 2tb drives I'd go raid 6, but it doesn't seem to be an option on the ICH10R, I'm trying to verify that.

Since you're going for 5 year life span as opposed to max performance, raid 6 with a battery backed cache is a much much safer option. There's a few downsides to raid 5 and drive failures, ie no one expects a second failure while doing a rebuild, but while the rebuild is happening its basically a raid 0. And if one drive from the same lot failed, then the odds of another drive failing while the array is being stressed at its max for hours straight increases quite a bit. The guy (GoofyGoofT) formatting an external 2tb disk, took 28 hours to do, which might be fairly close to rebuilding a raid 5 array made of 2tb drives. Its just something to think about if you're going for 5 years of reliability. And please tell me its on a UPS.

I'm just trying to throw a different solution out there, or play devils advocate if you will.

 

[SunnyD]

http://www.intel.com/support/chipsets/imsm/sb/CS-022304.htm
http://www.intel.com/support/chipsets/imsm/sb/CS-022321.htm

The first link table lists the ICH10R supporting Capacity Expansion.

 

[LxMxFxD4]

http://www.intel.com/support/chipsets/imsm/sb/CS-022304.htm
http://www.intel.com/support/chipsets/imsm/sb/CS-022321.htm

The first link table lists the ICH10R supporting Capacity Expansion.

Perfect.

Thank you!

 

[Boggs]

You can extend the array/volume on ICH10R but it takes a long time, much longer than initializing or formatting. I'm adding one 1.5 TB drive to a RAID-5 array of three 1.5 TB drives and I'm looking at a 10 to 15 day process! No kidding! Data migration starts immediately after you add a drive. You have to let it finish before rebooting the PC and going to Computer Management / Storage to resize the volume (partition). You can reboot in the process but DO NOT resize the volume (partition) until data migration is complete or data loss WILL occur!

 

[taltamir]

1. Never ever EVER! use RAID5 from an integrated mobo controller.
2. You can't make a 2 drive RAID5 array.

just use RAID1 (mirror), it will make your life so much better.

 

[FishAk]

Running a RAID 5 array is very risky. Read this link:


http://www.miracleas.com/BAARF/RAID5_versus_RAID10.txt


RAID 5 doesn't check parity on read, so when a drive starts to return errors, corrupt parity will be calculated and the RAID 5 integrity is lost. Since this isn't reported to the OS, you won't know you have no redundancy, and if a disk fails at this point, you loose data.




Whatever type of RAID array you use, if you don't have a complete backup outside the array, you are risking whatever data is on the array to total loss. Not having a complete backup is just plane stupid. Since you obviously have a satisfactory backup- including an image of the OS/program partition- the easiest, and probably fastest way to change capacity, is to break your array, and build the one you want whenever you get the disk(s) you want.

 

[Spikesoldier]

1. Never ever ever! Use raid5 from an integrated mobo controller.
2. You can't make a 2 drive raid5 array.

Just use raid1 (mirror), it will make your life so much better.

qft

 

[George P Burdell]

RAID5 is not worth the trouble in the long term. Just go RAID1 or RAID10.