Sign in with
Sign up | Sign in
Your question

RAID 10

Last response: in Storage
Share
May 31, 2010 4:55:29 AM

Looking at setting up a RAID 10, 4 drive system.

If I was to remove one of the two of the "mirrored" drives and place them in another computer as a standalone slave, would the data be readable/usable? Or would the RAID have to be rebuilt before the data is useful again?

More about : raid

a b G Storage
June 1, 2010 1:53:59 AM

As far as I know, the single disk is useless by itself. The other three drives will then require an additional drive to be added, and for the raid to be rebuilt.

Mind if I ask why you're asking this question?
m
0
l
a b G Storage
June 1, 2010 6:57:58 PM

A RAID 10 can withstand the loss of any one drive. That drive (if 'pulled') would be basically useless on its own.

One of the 'mirrors' can be pulled (ie both drives of a RAID 0 set) and the remaining RAID 0 drives could be used to rebuild the array. Potentially the 'pulled' RAID 0 could also be used to rebuild an array elsewhere assuming compatible hardware.
m
0
l
Related resources
June 1, 2010 10:00:22 PM

Thank you both for your answers. Its unfortunate, but it is what it is.

I do a lot of A/V projects. I use to store the very, very pertinent data on DVD's. But since they are, well, only so big, I wasn't able to save a lot of raw data. Well, since the cost of HDD's have dropped considerably, I've been thinking about using hot-swappable HDD's and storing entire projects on them for work and (ahem, I know) archiving (now, before you get on me, I u/s data rot and degradation, and I will be making multiple copies.... hopefully it will work semi-long-term??? :ange:  )

Anywho, the idea was to setup a RAID 1 so that I automatically have two sets of drives per project (one main, one backup) that could be put into an array whenever I had to access the project. Then I started thinking, well, hell, maybe I'll just do RAID 1+0 for the performance end.

But....

4 drives per project is just way too expensive over many projects. Thus the idea that maybe I could pull one or both of the mirrored drives, store those, and have them usable if needed by either slaving them or putting them back into another RAID 1+0 array (without a ton of downtime to rebuild, hopefully)

Any ideas?
m
0
l
a b G Storage
June 1, 2010 10:23:54 PM

Realistically, a RAID setup won't help you with portability. You could set up a NAS/Home Server, and then be able to access files from any computer on your network. As for transporting, if other people need the files, you could just get an external HD and just transfer what you need over.
m
0
l
June 1, 2010 10:34:40 PM

Its not necessarily about portability as much as it is about each project being btw/ 500GB - 1 TB avg (more or less, give or take). Setting up a SAN or NAS to access every single project is WAY too far beyond my means (many, many TB). As far as an external, that is practically what I am trying to do. A 4-bay easily swappable DAS.

I figured a 4 bay swappable enclosure hooked up via esata (PM or direct) or multilane would work perfect. Then just swap the drives for each project.

I was hoping for the performance of RAID 10 or 5 (maybe) but could not afford 4 drives per project to be able to build this, and then swap each set of 4 drives in and out for each project.

Thus, I was hoping I could just have 2 drives (of 4 needed for RAID 10) and store those, and then the other 2 drives would rebuild themselves with each different project. Sounds like a no-go?
m
0
l
June 1, 2010 11:12:59 PM

If you are using the same controller. You should be able to pull the mirror drives out.

As long you are using the exact same RAID controller, it should detect a fault in the array and from there you can proceed to rebuild the data.
m
0
l
June 2, 2010 12:22:38 AM

Does a port multiplier inside the enclosure qualify as a controller? Is it this that handles the raid setup in an enclosure like this or is it the actual PCI sata controller of which the PM plugs into the controller?

This is my idea:

ENCLOSURE -----------------------------------------to-------------------------------------------------->COMPUTER

4 HDD's ---- (sata) -----> 4x1 PM or Multilane --- (esata or multilane)----> PCI RAID Controller on Desktop (or) Expresscard on Laptop


This way the enclosure could be plugged into any computer. Thus, is the enclosure self-encompassing or not?


On top of this, perhaps I am not very well-versed in RAID 1. I know the data is mirrored and then stripped. How does this relate to 4 drives. Do 2 drives set as typical RAID 1 and then that data is mirrored across 3 and 4?

Would 3-4 have to be reformatted before using them again in a different data (project) set / RAID?
m
0
l
a b G Storage
June 3, 2010 4:43:42 PM

Hmmm, things are getting confused here.

RAID 1 requires 2 drives minimum. RAID 0 requires 2 drives minimum. Added together we can build a RAID 10 with 4 drives minimum.

So, here's a recommendation. Build a RAID 0 'in' your computer using the intel matrix storage manager. Buy a 2 bay DAS and build a RAID 1. Or even a 2 bay external enclosure and use the intel matrix storage manager for the RAID 1.

Now, do your work on the RAID 0. Save it on the RAID1, and port it, if necessary, with an external hard drive.

So, we now require 5 hdds. Probably 1 or 2 tb? and 2 external enclosures (1, 2 bay and 1 single bay).

Current prices for today's sale at NCIX.

5 x 1tb cav black = $89 x 5 = $445 Canadian about the same as $US

5 x 1tb green ears = $66 x 4 = $330

cheap 2 bay enclosure = $45
cheap 1 bay enclosure = $23

Total $400 to $513.

However, RAID is not something to do on the cheap, or play with. If you are doing that much high intensity work with tb sized files... Its time to build a proper system with a good NAS.

The above system will work quite well on the cav black drives. Keep everything cool and your fingers crossed. Sooner or later something will fail but you've got a little redundancy built in. Good Luck.
m
0
l
!