Does anyone know of a guide to configuring LVM on top of mdadm RAID 1? I set this up on Slackware current a couple of days ago and had an issue when trying to reconfigure lilo. The system booted fine but I couldn't make changes to lilo.conf; lilo would complain about /dev/md0. Sorry; I've since gone back to just RAID 1 without LVM so I don't have the exact error message.

On reflection I think it was my fault: instead of creating just one RAID 1 device (sda1 and sdb1) with LVM on top, I should have created two -- a small RAID 1 device for /boot (sda1 and sdb1 to make md0) and a second RAID 1 device (sda2 and sdb2 to make md1) for the LVM volume (with lvroot, lvswap, lvusr, lvvar, lvhome, etc.).

I was surprised to find no Slackware-specific information online about this setup. I would like to get it going again some time, hence the request for a guide. I did indeed have this setup running fine on a server for some years but I didn't take notes!

In fact, that's the setup I have on the machine I am using while typing this. I don't have my boot device set correctly in lilo.conf in that it isn't pointing to the /boot raid device but instead to one of the base drives.

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Oh I see! So I should have boot = /dev/sda in lilo.conf, instead of boot = /dev/md0 ? Another question while you're here: I presume I set the partition type to Linux raid autodetect and not Linux LVM when creating the partitions in the first place (with fdisk)?

Oops. Actually, I lied a bit. I don't have that setup on *this* machine but it is that way on my primary desktop (and other servers). Unfortunately, they are all using grub2 instead of lilo. This machine uses lilo, but has only one drive (it's a laptop).

So, I guess that's quite a bit of lying, actually.

This fellow seems to have it figured out: http://prithak.blogspot.com/2013/07/...-on-linux.html

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Here's my own Slackware-specific documentation:

• Setting up a LAN server using software RAID 1 or 5
• Using LVM

Cheers,

Niki

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Thanks. The problem on this occasion was that I set up a single RAID 1 array and put LVM on top. That meant /boot was inside LVM which, as your notes remind us, will not work. I don't know why I did this because usually I create a separate /boot partition. Anyway, lesson learned.

This was very helpful, Nikki! I had issues similar to the OP when I started up my NFS server using LVM over raid5, but I ended up setting up two volumes and wasting an entire 1TB disk for "system" files when I could have used this writeup to store everything on the raid. Thanks again!