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[ubuntu] recovering data on a raid array

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http://ubuntuforums.org – Hi all, I have three 1 TB drives on my Ubuntu machine that I was using in a RAID 5 array. I had 50 GB on each that I arranged in a logical partition that I used for the base installation. The other 950 GB I used for the RAID 5 array. Sadly, I managed to format the section that had the base installation. Silly me. Now I want to get the data off the raid piece. What's the best way to do that? Is it to just reinstall the OS on the 150 GB logical partition? The RAID 5 will be fine as long as I tell it it is a RAID 5 array? This seems the only way though I'm nervous that I could lose the dat (Hardware)

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Submitted by colm on 09/16/2012

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Before my installation of 12.04 server I read a lot on the forum about raid install and problems with Grub not being able to boot from anything other than a raid 1 array. However I had no problem at all with installation on a raid 6 array (5 disks) using mdadm.

What I did using Alternate 12.04 CD:

1. Choose Manual partion 2. Wipe all 5 drives 3. Assign all drives to a Raid 6 array 4.

A while back I created a RAID 6 array consisting of 5 2TB drives and formatted it with XFS and set up the block and stripe size appropriately.

Yesterday I added two more 2TB drives to the array and it is almost done reshaping the array. While running that I realized that XFS is optimized for the number of drives, and so far as I can tell there is no way to change that after the fact.

I have a question about speed performance with two separate SSD drives comparing them to RAID mirror array.

I have a raid 5 array constructed of three partitions, one of which is another array. This array should be assembled during boot so that it can be mounted and other services can access the mounted data.

After a restart which stalled, I did a hard reboot and now mdadm can't see the RAID 6 array anymore, LVM can't find the volume which was on that raid array.

I have just flashed my BIOS and now my machine does not detect my raid5 array! It has three 2TB drives in it so that is a LOT of data that will be lost!

I have NOT deleted the array and it does not offer me to reboot

I'm using Nvidia MediaShield! and Windows 7. Any ideas guys? Thanks!

Update: here is the GUI raid configuration.

My understanding of RAID 0 is that the data is split and striped across all of the drives in the array.

Growing a raid 5 array 2 years 43 weeks ago

Hello,

I have 3 x 1.5TB drives is a raid 5 array, at the moment the storage capacity is enough, but soon I will need to expand this. I have a spare 1.5TB drive that I am thinking about adding to the array.

So far I have read mixed articles/posts, some saying it can be done, others say it can't.

From what I understand I use:

I have 4 2TB hard drives and I was thinking about using Raid 10. This would give me 4TB correct? My next question is would it be easy to add more hard drives to the raid array. For example if I bought another hard drive can I add it to the array without backing up any data?

Basically I want to be able to start off with 4TB and when the space becomes full add more space as needed.