Raid controller

work in progress.

Introduction

A fast and reliable storage controller is one of the most important parts of a Proxmox VE server. This article lists some good working hardware raid controllers and some information about the used configurations. If you wonder how to figure out which Controller you have, log into your Proxmox server and type 'lspci' on the commandline. Then look for a line with RAID Controller or similar.

We are talking about "real" hardware controller, not the so called "fake" ones, the ones that usually are "embedded" in the motherboard. Such controller in fact don't have dedicated hardware but are software - bios/firmware based, so not reliable and not good performer (and are NOT supported by Proxmox, if they work is only on your own risk). Paramount feature for real raid controller if you want high performance is a on board cache and "write back" mode enabled. This way the OS had not to wait until writes are physically done on hard disk, they are immediately wrote on the cache and the controller will take care of subsequent write. If you don't want to loose your data in case of black-out, you need the so called "BBU", a battery backup on the controller that keeps data that are not yet saved on disk available until power comes back. In short, you need a RAID controller with cache and write-back, and you can safely enable write-back only if you have BBU (or similar solution, like a SSD cache instead of RAM one). Remember that a RAID controller with write-trough instead of write-back behaves really really badly With the command pveverf you can have a rough idea of the performance. Here some values just to have an idea (the FSYNCS/SECOND value of pveperf)

Single SATA WD 400GB: 1360.17

3 x 15K rpm sas RAID5 with write-through: 159.03 (YES, only 159!)

same as above but with write-back enabled: 3133.45

3Ware

9690SA SAS/SATA-II RAID PCIe (rev 01)

This Adapter is working well under Proxmox. Attention: make sure you have write cache enabled and use a BBU! Without write cache the vms seem to 'hang' or 'freeze' sometimes. Performance give about 50MB/s on a Raid 5 with 3 HDD's a 1TB

3dm2 Management tool

debs available from http://jonas.genannt.name

install key

 wget -O - http://jonas.genannt.name/debian/jonas_genannt.pub | apt-key add -

add to /etc/apt/sources.list :

deb http://jonas.genannt.name/debian lenny restricted

install

aptitude update
aptitude install 3ware-3dm2-binary 3ware-cli-binary

start service

/etc/init.d/3dm2 start

note firefox does not display all of the screen correctly [for anyways for last 3-4 years ]. so i usually use konqueror

connect - login as admin , default password is 3ware

https://ipaddress:888

configure

Change password , allow remote access, change default port . add NAT access thru firewall. ...

Adaptec

All Adaptec controllers with BBU unit are known to perform well. If possible, take one with "Zero-Maintenance Cache Protection", e.g. Adaptec 5805Z.

Confirmed

Adaptec 2405 Controller completely working (RAID10), out of the box. But be aware, it has no possibility to extend it with an BBU (Battery Backup Unit).

Configuration

Raid 10

Management tools

See Adaptec_Storage_Manager

Areca

ARC-1210, ARC-1212 and ARC-1222 works very well with good speed

HighPoint

HighPoint 3510 - RAID 10. Works very well.

Compaq / HP

Smart Array (using in-kernel cciss driver)

• 6i
• 400i