Automated Software-RAID setup for Proxmox 3.x

[Odiobill]

Hi All,

After some consecutive raid-controller failures on different servers, we decided to switch to software RAID instead of hardware cards to get rid of any possible single point of failure.

It's not possible to use software RAID from the standard Proxmox VE installation. However, following the howto that Dominic Pratt shared here (at http://forum.proxmox.com/threads/14299-German-HowTo-Proxmox-VE-3-0-with-Software-RAID) it is possible to "migrate" an existing installation and use this setup.

After experimenting for a while with migrated installations, I built a simple shell script that automatise the procedure. It is intended to be executed just after a fresh installation of Proxmox VE (that should be done on /dev/sda, the first available disk), and it accepts an optional parameter to have a specific raid type for the "data" raidset, while it will always generate a very small raid1 configuration on multiple disks for /boot, too.If not specified, the raid type that involves the rest of the disks space will be 1, 5 or 10 depending on the number of available volumes.

Feel free to try it out: I hope it can be useful for somebody else, too! For simplicity, I did put it on my home server, and it's downloadable at the following address: http://bomboniera.nl/pve_software_raid.gz

Cheers,

--
Davide Lucchesi

 

[gkovacs]

We have had a really bad experience with mdraid on Proxmox VE 1.x, so we decided to go back to hardware RAID.

We created the mdraid arrays and the LVM with the default Debian installer, then later added the PVE packages. Performance was good, but due to some instability in the OpenVZ kernel, we always had 1-2 monthly freezes that required hard resets. Usually the arrays (and the filesystems) were able to recover, but finally one of these reboots killed the md array so badly that it could not recognize the volumes anymore and we lost all data. And these were servers with UPS, so the disks never lost power!

In my opinion the best way is to operate multiple servers with capacity to spare, using identical, low-cost hardware RAID10 controllers and sensible ext4 mount options (barrier=1, data=ordered). The Proxmox/OpenVZ kernels are simply not stable enough for storage provision, see the latest IO hang threads for example:
http://forum.proxmox.com/threads/14309-CRITICAL-Huge-IO-load-causes-freezing-during-backups

 

[degrootm]

I was all over this forum looking for a way to get ProxMox 3.0 to do software RAID much like I had working on 2.X.
Started out with the same approach and things went down hill fast at the end. So after a few days of tinkering I was ready to give up (almost).
Then I found this link http://www.cesararaujo.net/proxmox-v3-software-raid/ and it works as advertised, I was even able to fix my half working previous attempt. The big clue was that my GRUB needed the preload of raid. At least that seemed to fix it. So I would recommend starting with that link if you are using 3.X and save yourself a good deal of time.

 

[kotakomputer]

I'm using mdam software RAID 1 for more than 100 servers w/o any issues, it's better than no RAID at all. When 1 HDD fail then mdam will report. Unfortunately Proxmox 3.x degraded its support for s/w RAID even come from M/B BIOS (version 2.x support s/w RAID).

I have setup RAID 1 using BIOS feature but Proxmox can not see the RAID instead 2 separated disk. The bad news is Proxmox core-team will not fix this, which makes BIOS RAID useless. Hopefully they support BIOS RAID again in next major version

 

[pirateghost]

I'm using mdam software RAID 1 for more than 100 servers w/o any issues, it's better than no RAID at all. When 1 HDD fail then mdam will report. Unfortunately Proxmox 3.x degraded its support for s/w RAID even come from M/B BIOS (version 2.x support s/w RAID).

I have setup RAID 1 using BIOS feature but Proxmox can not see the RAID instead 2 separated disk. The bad news is Proxmox core-team will not fix this, which makes BIOS RAID useless. Hopefully they support BIOS RAID again in next major version

Your BIOS RAID is also what we like to call FakeRAID. Its worthless. Just use a real raid controller or use software raid

This isn't something the proxmox guys need to fix. It's something the hardware manufacturer needs to do to stop using cheap controllers on motherboards or something you need to fix by buying proper hardware.

Sent from my Nexus 5