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I have installed WHS without incident and in the setup process and initial testing worked quite well. (Note to team: Nice work, and the documentation is outstanding.)

However, when the first big WHS backup begins, after 10 minutes or so, I get a disk error - "unable to find sector" that's thrown to the guest event log - nothing in the host logs. Usually the guest recovers, but the application fails in the guest. It's thrown as an IDE class error.

I've run CHKDSK on the virtual media affected, which is an 850GB partition on a 1TB drive -- nothing turns up. The drive passes Hitachi's tests as well. After the failure, and after running CHKDSK, the drive properties show garbage in the "Used Space" field -- i.e., back slash, percent signs, spaces, etc - instead of an integer. There is a "repair" option in WHS, but that succeeds, only to have the backup fail again with the apparent disk error.

I've tried dropping the virtual media, reallocating it to VBox, and repeating the process, but get the same result.

I also tried using a different ICHR10 drive with a smaller partition. It ran a bit longer, but gave the same result.

The error thrown is not for boot drive for the Guest, but rather it's the one WHS is trying to write the backup to. Controller is Intel ICH10R.

I've seen the VirtualBox warnings about slow drive subystem performance, and suggested increases for timeouts, but I'm dubious. The host OS is speedy.

ENVIRONMENT Host Vista x64, Guest Windows Home Server (WHS) w.32, Virtualbox 3.0.6 with 1GB, 80GB boot partition. Hardware: E5520, 6GB, 3Ware 9650SE RAID 5, Intel ICH10R (non-RAID) SATA.

knowlengr wrote:I've run CHKDSK on the virtual media affected, which is an 850GB partition on a 1TB drive -- nothing turns up.

What does "an 850GB partition on a 1TB drive" mean? Are you using raw disk access to a physical partition?

Sorry, not raw.

I added the "partition" using the Virtual Media manager. That was misleading on my part to call it a partition. It is the only item on the physical disk and the only item in the only partition, but the VM doesn't know that.

Thx for the reply.

Ok, so what you are saying is that you created an 850GB virtual disk in (dynamic?) VDI format, which is currently the only file on your 1TB drive. I also assume NTFS is the filesystem for both guest and host.

Though I'm not sure this is getting us very far. 850GB is not near any magic numbers, so I wouldn't have expected a VBox bug to show up. If you were using raw partitions then I might have suspected a conflict with the host. Apart from a real problem with the physical disk or a bug/limitation in the guest OS then I can't think what could cause this. You mentioned timing constraints, but surely the constraints wouldn't be that tight.

mpack wrote:you created an 850GB virtual disk in (dynamic?) VDI format, which is currently the only file on your 1TB drive. I also assume NTFS is the filesystem for both guest and host.

Exactly.

mpack wrote:Apart from a real problem with the physical disk or a bug/limitation in the guest OS then I can't think what could cause this. You mentioned timing constraints, but surely the constraints wouldn't be that tight.

Agreed. I browsed the WHS message boards and FAQs (and they're thin compared to the other Microsoft OS offerings) and didn't see anything helpful, though several folks have attempted WHS in VM's. None with Virtualbox posted any messages AFAIK.

As to whether the guest WHS OS (an adaptation of Win 2003 Server) broke it, there is a notion of WHS corrupted backups, e.g., caused by a failed drive, or powering down a machine during a backup. WHS has a repair utility, which I ran, and it claimed to have cleared it up. The problem recurs. It's possible that WHS utilities can't or didn't clear it up, but since this is a new build of both host and guest OS, and the usage has been so light to date, I'm suspecting an issue with the VM setup.

The suspicion could be ill-founded.

I could try a competitive VM and also a dual boot on the same machine to verify that it's not an issue with the underlying hardware - assuming the MS licensing will allow it.

knowlengr wrote:I could try a competitive VM...

Or a competitive server OS as the guest VM, same sized VDI (maybe even the same VDI, reformatted internally). Though that might be a steep learning curve for you and not have the features you want.

If a different OS using a different filesystem (say, Linux using an ext3 filesystem) has similar problems then I'd think that would pretty much prove a VBox bug - or a physical problem with the drive. If a Linux server worked ok then that would indicate a problem with WHS.

UPDATE - No resolution yet. I reinstalled WHS on Parallels (hmm, these products are strangely similar) and got the same result -- worse, as this time the drive "disappeared."

I'm going to do more testing in the non-VM environment.

The plan to create a dual boot environment is easy in principle, but I haven't figured out how to hide the Vista partitions from WHS, which wants to reformat everything in sight when it installs. I'll get some help from Paragon on that.

I will send in the RAID drive's battery unit for repair --a possible issue, since the O.S. is installed here -- though the errors are being thrown when writing to the non-RAID partitions.

More when I learn more.