HP recommendations for Boot from SAN

[Ian Dennison_1]

Am reading the Whitepaper PDF named "HP-UX boot over SAN", it recommends the following,...

It is not recommended to configure boot LUNs on array controllers with “continuous high application data activity”.

Do I need a dedicated array controller for boot devices here? Can anyone place this in context for me? Share and Enjoy! Ian

[Venilton Junior · Accepted solution]

Hie Ian,

I was reading the document and I understood that it will depends of your SAN environment.
Like, if you have an heterogeneous SAN with MSA1500 and in this Storage you have a large Database, it's not recommended to use BFS.
Other case is using an EVA, but do you still have an application that uses larges I/O requests.

If you don't have a large SAN environment, you can use BFS with no problems.

I always use two disks in raid1 in the local controller just to boot the server, but this is my opinion. :D

Hope that helped u

Brgs

[Duncan Edmonstone]

Ian,

I think this warning should be taken in much the same way as "Caution contents are hot" warnings you get on cups of coffee from certain fast-food outlets...

i.e. Sometimes its necessary to state the blindingly obvious to deal with the 1% of people in this world who seem determined to ignore simple common sense.

In this case - if your SAN storage device is already heavily loaded, booting off it might not be a good idea - not least beacuse I expect that there aren't too many tests run in the labs on this sort of situation, and no doubt timeouts during early stage bootstrapping of the OS could have inconsistent results.

You don't need a dedicated FC port on your array just for boot - nevertheless try not to use the same port as you use for your 100K transactions per minute OLTP database...

HTH

Duncan

[Rob Leadbeater]

Hi Ian,

I've no experience with HP-UX and SAN booting, but all the Tru64 UNIX servers I've managed in the past were set up to boot from SAN.

In fact, of the dozen or so servers none had local disks, and just a pair of HBAs talking to either HSG or HSV based storage.

The EVAs were always pretty busy, but I don't ever recall having problems booting from them...

Hope this helps,

Regards,

Rob

[Digex]

Once you boot from disk the I/O is minimal since the OS is running in memory. I hardly see any disk activity once the server is up and running. I would watch not putting a boot LUN on a LUN that is on the same physical disk say on a MSA. On EVA this is a different story since the EVA does it virtually and writes the data to a bunch of disks and normalizes it accross the array. We use boot from san on all our blades connected to EVA. THere is no local storage controllers. This helps us to take one blade out and replace it with no issues in case of hardware failure. We always keep one blade in the chassis as spare. With our VM servers we just migrate the active VM's and swap the blade out in maintenance mode. Can't do all this with local drives. I love boot off san and blades :)