What is the best way to configure mdadm RAID under Proxmox?

Question

linux

Good day,
There was a need to set up a platform based on Proxmox VE 3 for several VMs with Debian GNU / Linux on board. For these purposes, an HP Proliant DL 320e Gen8 was purchased, and 4 SATA HDDs of 1Tb each were purchased. It was decided not to purchase a hardware controller, but to combine disks into RAID using mdadm. And here the question arises - as you know, Proxmox "out of the box" cannot be installed on a soft raid, which is why there are two options for the development of events - put Proxmox on sda and after installation already collect the array (s), or install Debian Wheezy and already "on top" "roll packages and kernel from the Proxmox repository.
In the first option, easy hemorrhoids with the transfer of partition tables and themselves, the transfer of LVM, etc.
The second option is simpler, more convenient, and allows you to easily set up your own structure for arrays, LVM, partitions, and so on. The only thing that confuses is whether the Proxmox image posted on the site contains any differences or changes from installing on a "regular" Debian?
Also interested - does it make sense to collect RAID1 for the needs of Proxmox, and for RAID5 data, i.e. to do two arrays, or all - how to drive Proxmox data and VM images onto one RAID5 array? The host will run lightly loaded virtual machines, so there are no special I/Os. RAID5 is chosen as a balance between reliability and available disk space (and this is important in this case, just right).

Answer 1

Debian requires some tweaking after installing proxmox on top of it, so I would advise you to install proxmox, and then migrate to the raid, while the partition without virtuals will go quickly and smoothly. Raid5 is a good option for everything, but remember that any raid is not a replacement for a backup.

Answer 2

I always do this, I install pure Debian, during the installation, when the disks are determined, Alt + F2, I configure the md array through mdadm, I create partitions with fdisk, I return Alt + F1, I put the system. After that, you need to /etc/default/grub:
and
update-grub

Answer 3

1) Does not contain, set it up many times.
2) You have 4 disks, what kind of raid1 + raid5 can we talk about?
3) Build better raid10, the place is very worried, use large disks, since they cost a penny.