The operating system couldn't be loaded because the kernel is missing

[Udayv_TCS]

Hi,

I am trying to get a fresh install of Windows Server 2016 working on UCS B-Series blade with UEFI and boot from SAN and seem to be hitting a brick wall.

The OS is installed and I can see the Windows Boot Manager entry and the EFI files are present. However, every boot loads the logo and then stops with:

The operating system couldn't be loaded because the kernel is missing or contains errors. File: \Windows\system32\ntoskrnl.exe Status: 0xc0000185

I have tried different media with no luck. I can see the file is present if I load a LiveCD.

This is connecting to a PURE storage array over FC and we already use boot from SAN for our ESXi hosts running on the same blade chassis.

Thanks

[bre_cedwards]

Were you able to resolve this issue? I'm seeing the same issue with UCS-B booting from a PURE SAN over FC.

[jkim@recoverypoint.coim]

Same issue here, UCS firmware on 4.1(2b).  

[Kirk J]

Recall a case a few years ago where that was related to compatibility: Pure storage only supports 4MB SCSI commands but Microsoft Windows sends 8MB SCSI commands during UEFI boot from SAN operations

Do you have the option to try booting legacy (non-uefi) ?

Kirk...

[Ricardo Fiorentino]

Hi Kirk J,

you are right.
We had the same issue and called the pure support. 
After that, the pure support changed the setting for windows on our pure system.

Now the Windows Server 2022 is booting with UEFI.

Regards

Ricardo

[brandonayub023]

Same issue here, anyone found a fix for it yet?

Regards. Team Storageboxdirect

[marcpe]

Same issue here with UCSM 4.2(1f), B200M4, Pure array on FC and Windows 2k19.

Impossible to boot windows after complete uefi install. Error 0xc000007c, ntoskernel missing or corrupt. I tried to repair the boot with a custom iso (vic driver injected), no result. I also tried to run "sfc /scannow" on C: partition from WinPE but no corruption found.

Had to switch to legacy boot type. I'm in a lab environment so it's not a big deal.

Anyone opened a case to Cisco or Pure ?

Regards

[Mark Morsing]

Same issue here
B200M4, B200M5, Pure Array on FC, 2k16, 2k19.

Regardless of legacy or UEFI, we get these errors after installing.

UCSM 4.1(3i)
Pure 6.3.6

[ac513]

Seeing the same here. B200M6, Pure Storage over FC, UEFI SAN boot with ESXi is fine. But UEFI SAN boot to Windows results in the missing ntoskrnl error after first reboot from clean installs of Windows Server 2019/2022.

The 4/8MB SCSI command discrepancy between Pure and Windows sounds like the next logical thing to chase based on comments here. Does anyone know where/how this is done in Pure?

EDIT: Can also confirm the exact same LUN and server combination boots fine when configured legacy mode.  Reaching out to Pure support and if there's any additional details I can offer others beyond "call Pure", I'll be sure to update everyone.

[marcpe]

Thanks for your actions with Pure support.

[ac513]

Pure applied their fix, and everything's working now.  However, I didn't get any elaboration on what the exact "tunable" as they call it, actually is. (I asked, and they said "it's the thing we need to set to fix the issue"... Yea, duh...) We'll try to get more info out of our account rep, I hate that this is wrong out of the box with information being so obscure.

[ac513]

Details on the specific tunable from Pure... It's the SAN command size issue mentioned in this thread, as expected.

Essentially the Cisco KB is right--by default we support up to 4 MB I/O reads which is an issue with UEFI in general--it issues a 7 MB read during boot that fails and causes blue screen or other issues with Windows. We solved this with vSphere by working with VMware to add intelligence to the vSCSI layer so that ESXi looks up the default max IO size of the storage platform and will split I/O itself. So virtualized Windows using UEFI (which is becoming the default these days) doesn't require intervention.

Baremetal Windows is another story. Same issue, but requires configuration on the array with a tunable we call PS_DEFAULT_CHUNKED_READ_ALLOWED that, well, allows larger reads (up to 8 MB).

---

[marcpe]

Thanks for sharing this information.

Have a nice day.

[AmberRun]

This was really helpful. Thanks for the insight, helped fix my problem

Regards, Team Mybakersfieldrealtor