Boot from SAN

[pcantoni]

Hi everybody,

I'm looking for documentation about Pro[u]&Cons[/u] of booting ESX from a SAN.

Some advice ?

Thank you in advance

[ZMkenzie]

Esx installation is very lightweight (1.8gb) so installing it on SAN is not a big problem, but you should definitely use local disks for swap. If you put swap on SAN it will really slow down things when memory became a problem. If you don't have local disks use a dedicated disk/raid group for swap.

Anyway esx is very straightforward to install so i don't think that booting from san is an advantage. If you change hardware or add new machines to your vmware cluster installing esx from scratch using local disks takes less than 15 minutes and you can also script that, so, can't see any advantage on booting from san.

The only "pro" about san boot is that you won't need internal disks, but, i don't see this as big feature. Some hw vendor is also selling machines with 4-8-16gb flash drives, this could be a better choice if you need a machine with less mobile parts (and more swap/io performance).

[VMWareNewbie]

Here is a doc for you.

Link - http://pubs.vmware.com/vi3/sanconfig/wwhelp/wwhimpl/common/html/wwhelp.htm?context=sanconfig&file=es...

Info pasted below.

Introduction

Before you consider how to set up your system for boot from SAN, you need to decide whether it makes sense for your environment.

Use boot from SAN:

• If you don’t want to handle maintenance of local storage.

• If you need easy cloning of service consoles.

• In diskless hardware configurations, such as on some blade systems.

Do not use boot from SAN:

• If you are using Microsoft Cluster Service.

• If there is a risk of I/O contention between the service console and VMkernel.

Note With ESX Server 2.5, you could not use boot from SAN together with RDM. With ESX Server 3.0, this restriction has been removed.