Does HP support booting off external disk?

[David Reno]

I have seen many e-mails discussing how to boot off an external disk. Is this supported by HP? Specifically, booting of HDS 9910?

Thanks in advance, I will be diligent with points.
David

[Jordan Bean]

I don't know what HP's policy is on external boot disks, but I'm quite comfortable putting EVERYTHING on an external storage array, like the EMC Symmetrix, with multiple paths. EMC supports this, but they don't recommend it. They say I'm living dangerously; If the entire Symm goes down (unlikely), then my host is toast. So what? The host would be useless anyway.

[Patrick Wallek]

Yes, Jordan, your host would be useless, but at least you'd have a useless host that you could actually log into and see if the problem was fibre related, or the EMC, or something.

I have never been thrilled with the concept of booting off of an external array. To me that's playing russian roulette. You're eventually going to lose.......

[harry d brown jr]

David,

I've been booting HP's off external disks (jbod) and external disk arrays for years without any issues! I was booting off EMC's SYMM's when HP and EMC said it wouldn't work.

Now, I understand Patrick's stance, and I agree, that every system should always have a bootable internal disk, especially for trouble shooting, because without it, you are at the mercy of your external storage.

Tomorrow, I will have my SA's testing booting an A-class server off a SAN, made up of a Connectrix and EMC Symm's. I'm trying to get EMC off their arse to certify hundreds of servers booting from Symmetrix disks via the SAN. NOW, all of these servers WILL have internal disks for trouble shooting, but the goal is to have the ROOT DISKS mirrored remotely (38 mile sonet loop).

Another thing, we WILL be using Virtual Partitions, SIX partitions per N-class, and they will be booting from the SAN, and each partition requires about 36GB of disk. Now to get 6 partitions out of a 12 slot N-class, one must use DUAL PORT Fibre Cards and a high speed network card (Maybe another Dual port Fibre Card configured to do IP? - not sure yet), therefore 2 cards per partition yields 6 partitions. I don't have a choice, but to use the SAN for BOOTING and DATA!!! I'm not going to use L's or A's, because I will be reconfiguring these servers (the N-class's) in 18-24 months as either application servers or database servers (our software is being re-architectured).

Push them to the edge!


LIVE FREE or DIE
harry

[Bill Hassell · Accepted solution]

Internal and external disks are essentially nothing but different physical locations and depending on the box, different I/O. The only issue is the type of interface. Some older boxes cannot boot from the newer interfaces. This is a firmware issue along with appropriate drivers and revisions of the opsystem. As far as reliability and dependability, if the boot disk is part of a large SAN, if the SAN goes down then a lot more than just one server goes down, and even if you could boot from an internal disk, you would have to evaluate just what can be done with the big disks (and other systems) down.

[harry d brown jr]

Bill,

You are right, if the SAN goes down, and it has redundancy built in, then you have bigger problems than worrying about where you are booting from. If my users can't get access to their data, then who gives a shit if the OS can run or not, or where it could, or could not boot from, they don't (the users), and they pay the bills.


live free or die
harry

[Michael Tully]

Remember the 'T' series boxes.... All disks for these babies were external. Supported yes

We could have a debate all day about internal V's external. If there are internal disks why not use them to boot the system. (what else could you use 'em for ?) For DR purposes I guess it comes down to how much money a company is prepared to outlay as whether you could have remote mirrored disks.

[harry d brown jr]

Michael,

Why use external? What if I have an N-class server, with 6 CPU's, and I only have two internal disks (on the same SCSI bus) and I need to have 4-6 partitions on the server? -- Each Partition must have its OWN IO cards, hence IO paths.

Plus, I need the high availability, and I can't use clustering because my app sucks and can not be restarted automatically (very crappy app).


live free or die
harry

[David Reno]

(Whoops! I meant to post this here as a reply, but accidentally posted it as a new message! I guess I'll go there for any follow up discussion!)

Thanks everyone for joining in the discussion, I find it informative what others are trying and doing.

It seems no one however could answer the question about whether booting 11.x systems from an HDS 9910 is supported (or whether it makes sense to differentiate it from internal disks).

Thanks again,
David

[melvyn burnard]

Simply put, YES HP support booting off external discs.
The other points made are all valid, and you have to make the choice as it is your system ;-}
As for the HDS array, well yes you can boot off this array, but as it would be supported by HDS and not HP, then this is another variable to throw into your calculations.
Life is, unfortunately , never simple:-}

I have deleted your "in error" post