Notes for using soft RAID in Ubuntu

I recently encountered a very strange problem when I was doing soft RAID. The operating system version is Ubuntu12.04Server. I found the following article, which can solve this problem well. Soft RAID is used on Ubuntu11.10. When the system is restarted, manual intervention is required to access the system. There are two reasons: first, it is because the Initial Startup Process is interrupted after the software RAID is reduced, and confirmation is required. You need to reconfigure mdadm and regenerate the initrd file: Run dpkg-reco

Recently, I encountered a very strange problem when I was doing soft RAID. The operating system version is Ubuntu 12.04 Server.

I found the following article to solve this problem.

A Soft RAID is used on Ubuntu 11.10. When the system is restarted, manual intervention is always required to enter the system.

There are two reasons: first, it is because the Initial Startup Process is interrupted after the software RAID is reduced, and confirmation is required.

You need to reconfigure mdadm to regenerate the initrd file:

Run dpkg-reconfig mdadm

One step is to select "Start the system when RAID is downgraded" and select "yes.

Another reason is that at startup, busybox is always entered. This is a bug in Ubuntu 11.10, as described in the following file:

Need to modify:/usr/share/initramfs-tools/scripts/mdadm-functions

Set:

Degraded_arrays ()
{
Mdadm -- misc -- scan -- detail -- test>/dev/null 2> & 1
Return $ ((! $ ?))
}

Add a row and change it:

Degraded_arrays ()
{
Udevadm settle
Mdadm -- misc -- scan -- detail -- test>/dev/null 2> & 1
Return $ ((! $ ?))
}

Then, regenerate initrd:

Update-initramfs-u