Booting Win2008 from XP24K Exteranl Storage

[DJMC]

Hi,
Has anyone had any problems when externalizing a win2008 boot disk running on EVA5000 through an XP24K?
We have 4 server's all booting from EVA. I have mapped the Vdisk to XP24K (external Storage) and presented back to host, the EVA Vdisk is unpresented from Host.
Two of the server's boot ok, but the other two crash shortly after logging in.

All servers have the same OS build and the same HBA driver's, MPIO etc.

When EVA Vdisk is presented back to host it boots ok.

Anybody seen this before or any ideas on where to look.

Thanks,
D

[Nigel Poulton]

How many Vdisks from the EVA are you using and how are they carved up in the XP?

E.g. Do you have 4 Vdisks presented to the XP and have them mapped through the XP as 4 LDEVs? Or do you present a single Vdisk from the EVA and carve it up as 4 LDEVs on the XP?...... More detail needed.

Are you using the EVA Vdisks through the XP for paging? Or is the page file local disk?

[DJMC]

HiNigel,
We have one Vdisk on the eva , which is the boot disk C:, presented to the XP as one LDEV.
The page file is on a locl internal disk on the server.

D

[Nigel Poulton]

Hi DJMC,

Im a little confused as to your config. So let me just check I understand correctly......

You have a single Vdisk presented from the EVA to the XP. In the XP you say that you leave it as a single LDEV.

But you say that you have 4 Windows hosts booting from this Vdisk -

"Two of the server's boot ok, but the other two crash shortly after logging in"

Are these 4 servers all booting from the same LDEV/LUN?

Im confused

[DJMC]

Hi Nigel,
Sorry..

We have 4 server's, 2 EVAs and 2 XP24K's on 2 sites.

On site 1:
two serves have there boot disks on EVA5000. each is a 50GB Vdisk. I have mapped the eva Boot disk for server 1 to the Xp as a single LDEV (it is not devided up into multiple ldevs) and presented it to the host via a windows hosts group on XP ports 1D and 2D. I have unpresented the Vdisk to server1 from the EVA.
Server1 boots ok via the XP.

I have done the exect same procedure for server2, using its boot disk (another VDISk on the same eva), Presented to the same pXP ports but diferent host group, this server boots via XP but crashes shortly after logging in.

Site 2:
Is set up the sam as site one and hase same issues.

hope the amswers more questions than it creates.
D

[Nigel Poulton]

Ah OK that gives a much clearer picture.

What is the STOP message that you get on the Windows servers that crash? Does it relate to I/O timeouts?

What cache mode (on or off) do you have on the LDEVs?

Have you noticed any high WP on the XP or have any I/O latency related stats from the Windows host?

[DJMC]

The stop message doesn't give a discription and the HEX values change each time.

The Cache mode and inflow controll are set to disable for the external storage.

The array has very little on it right now. Currently it only have a few Luns for exchange and there has been no issues with that.

D

[DJMC]

Forgot to mention that when we put everythng back to the EVA the server boots ok with no problems at all, so the issue would seem to me to be with the path to the disk would it not?

D

[Nigel Poulton]

Hmmmmmmm sounds strange.

Is the MPIO and all of the HBA drivers etc supported on the XP?

You might try setting Cache Mode Enable=On for the boot LDEVs on the XP. Just in case its a latency issue.

Are you sure you have your Vdisks mapped to the appropriate LDEVs and there is no chance that the second Windows server is trying to access the same disk as the first Windows host? Long shot I know!

[DJMC]

Hmm
No, the Vdisk/Ldev mapping is fine and the MPIO and drivers etc are supperted. I should point out that each of these servers already have data disks presented from the XP with no issues.

D