(original article)

Re: Converting RAID5 to RAID6 and other shape changing in md/raid

13 February 2011, 01:58 UTC


I need help!

I did something, that in hindsight, is incredibly stupid!

For some reason, not relevant here (may be appropriate in a separate comment), I killed mdadm while it was reshaping a RAID-6 array from a chunk size of 64KB to 512 KB. It was at least 20% through when I did so,

System appeared to function okay.

A few minutes later I rebooted.

Note that I had 3 RAID-6 arrays:

md0 swap

md1 my main user data

md2 /

I have 5 500GB hard disks .dev/sd[abcde] /dev/sda1 has /boot, not in a RAID array.

Machine has a quad core AMD 64 bit processor with 8GB RAM.

There are 2 logical links from md2 to md1, including /home.

I am using Fedora 14, up-to-date with patches as of Friday morning.

mdadm - v3.1.2 - 10th March 2010

The RAID array being reshaped was md1.

The reboot started(completed?) to check md2, and then gave up.

The mdadm conf file says that md1 has an old and new chunk size, but no indication (to my eyes) that thee is a problem.

Attempting to redo the reshape command brings up an error message about not being able to add something.

The backup file is in /boot, and is the same size as when I checked it during the process.

This is my main development machine and the gateway to the internet - I have temporarily connected another machine to access the Internet.

I would appreciate advice, and will provide more details if you consider it relevant.

Thanks, Gavin Flower