Comments on: Setting up an encrypted LVM over RAID 5 https://billauer.se/blog/2010/01/howto-lvm-dm-crypt-raid-5-mdadm-fc12-fedora/ Anything I found worthy to write down. Thu, 26 Mar 2026 13:15:15 +0000 hourly 1 http://wordpress.org/?v=3.1.2 By: Superkikim https://billauer.se/blog/2010/01/howto-lvm-dm-crypt-raid-5-mdadm-fc12-fedora/comment-page-1/#comment-419 Superkikim Sun, 02 May 2010 09:55:42 +0000 https://billauer.se/blog/?p=472#comment-419 Hi, I desperately tried today to make RAID5 and LVM too. I have the following settings: 4 2TB drives on an Atom ION mobo and I'm booting Debian Lenny on an SD Card. At 1st, I have made GPT labels on the 2TB drives, then created a RAID5 with all 4 drives getting /dev/md0. So far so good... as you say. Then, I tried to parted /dev/md0. So wrote again a GPT label on it and then, when I create partitions, it tells me that the kernel will not be aware of changed until I reboot... I created 11 500GB partitions and a last one with the remaining space in idea to be flexible with lvm. Reboot... no device node for any partitions. I'm stuck on this for many hours now :-( I tried to put msdos labels on the physical disks, and then gpt on the RAID volume. Same problem. Anyhow, as soon as anything is GPT, it fails... Hi,

I desperately tried today to make RAID5 and LVM too.

I have the following settings:

4 2TB drives on an Atom ION mobo and I’m booting Debian Lenny on an SD Card.

At 1st, I have made GPT labels on the 2TB drives, then created a RAID5 with all 4 drives getting /dev/md0. So far so good… as you say.

Then, I tried to parted /dev/md0. So wrote again a GPT label on it and then, when I create partitions, it tells me that the kernel will not be aware of changed until I reboot… I created 11 500GB partitions and a last one with the remaining space in idea to be flexible with lvm. Reboot… no device node for any partitions. I’m stuck on this for many hours now :-(

I tried to put msdos labels on the physical disks, and then gpt on the RAID volume. Same problem. Anyhow, as soon as anything is GPT, it fails…

]]> By: Jacco Logtenberg https://billauer.se/blog/2010/01/howto-lvm-dm-crypt-raid-5-mdadm-fc12-fedora/comment-page-1/#comment-380 Jacco Logtenberg Tue, 26 Jan 2010 18:33:08 +0000 https://billauer.se/blog/?p=472#comment-380 Tried the same thing today, also without success, on CentOS 5.4. My main goal was to emulate a HUGE disk (6 TB), for experimenting with EFI/GPT partitions in stead of standard Master Boot Record. So LVM on a md-device is not an option. Virtual disks are really cheap. So I created a VMware virtual machine (VMware workstation) and added 6 1TB thin-provisioned disks to it. It doesn't take any diskspace (almost, approx. 100M for a 1 TB thin provisioned disk). Next step was to partition the disks (1 fd-type primary partition on each disk) en to create a RAID-array in the virtual machine: 4 1TB disks in RAID0 with "mdadm --create /dev/md0 --auto=part -n 4 -l 0 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1". So far so good. The option "--auto-part" does make it a partitionable array, according to the manpage. BUT IT DOESN'T WORK! Main problem is the devicenumbering, in particular the minor numbers. On a ordinary disk, minor number 0 is the whole disk, minor number 1 is the first partition, and so on. On a md-device, minor number 0 is /dev/md0, minor number 1 is /dev/md1, and so on. Don't know how to work around this. Tried the same thing today, also without success, on CentOS 5.4.
My main goal was to emulate a HUGE disk (6 TB), for experimenting with EFI/GPT partitions in stead of standard Master Boot Record. So LVM on a md-device is not an option.
Virtual disks are really cheap. So I created a VMware virtual machine (VMware workstation) and added 6 1TB thin-provisioned disks to it. It doesn’t take any diskspace (almost, approx. 100M for a 1 TB thin provisioned disk).
Next step was to partition the disks (1 fd-type primary partition on each disk) en to create a RAID-array in the virtual machine: 4 1TB disks in RAID0 with
“mdadm –create /dev/md0 –auto=part -n 4 -l 0 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1″.
So far so good. The option “–auto-part” does make it a partitionable array, according to the manpage.

BUT IT DOESN’T WORK!

Main problem is the devicenumbering, in particular the minor numbers.
On a ordinary disk, minor number 0 is the whole disk, minor number 1 is the first partition, and so on.
On a md-device, minor number 0 is /dev/md0, minor number 1 is /dev/md1, and so on.
Don’t know how to work around this.

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