the disk structure is corrupted and unreadable


I am having issues with a client's SBS 2008 server. The Server is a Hyper-V Virtual Machine

This morning, whenever you try to create a new file or folder on the drive you get the error: the disk structure is corrupted and unreadable

You can browse the drive, even open files and delete files but you can't create new ones or save files you've opened

Weirdly, the Exchange Databases reside on this drives and Exchange is running fine

In the event log is the following:
Windows was unable to save all the data for the file \Device\HarddiskVolume1\$Mft

Followed by loads of Event ID 55's asking for a check disk.

There are also logs stating a check disk has been completed, followed minutes later by the above again

Also a couple of users have complained about files they've deleted having come back to their desktops etc (they are roaming profiles) and files missing that were there prior to the weekend

I have managed to copy the data from the drive to another location

I would like to do a check disk but do I need to unmount the Exchange Databases first?



Dominic LennonOwnerAsked:
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Open an elevated cmd prompt and enter chkdsk DriveLetter: /f /r for all driveletter assigned to the VM. It'll tell you it needs to reboot to finish, y/n. Press "Y" to acknowledge, then reboot the server so the chkdsk can continue. This can take a long time, depending on the size of the virtual disks and the number of errors found, so make sure you do that while the server is not in use much (night or weekends), and warn the users before you start.

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Dominic LennonOwnerAuthor Commented:
Hi Rindi

Thanks for getting back to me

I am currently using SyncBack to copy off the data to another drive for safety.  I am also going to try and do a move mailboxes etc and move user profiles to get as much off the drive as I can before I do the check disk and reboot

just a bit paranoid about data loss, unless you think I'm overthinking it???????

I'll let you know how I get on.  Is the check disk likely to reset permissions as I think this has happened when it tried to carry out a check disk on the reboot I did on saturday morning


There's never anything wrong with making too many backups. Permissions shouldn't be a problem unless they are already corrupt. Chkdsk fixes file-system corruptions.

Something you may also want to do is check the host's RAID array for bad disks, and also run a chkdsk on the host's file-systems. You may also want to copy the VHD or VHDX files to a backup disk before doing that.
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Natty GregIn Theory (IT)Commented:
back up your files and roles if any and prep a new disk, re install and keep it moving. The disk is failing and those are your warnings.
Dominic LennonOwnerAuthor Commented:

Even on a vhdx where the underlying host is raided and shows no events or issues?
Dominic LennonOwnerAuthor Commented:
I ran it only with /f flag and it found errors which were corrected and the drive is back up and running as expected

Although being familiar with chkdsk in my 20 years of working in IT the error I was seeing was a completely new one, and when it's a client's server I get that lovely chilling feeling in my stomach!

Thanks for the pointers and I'll now move onto the lovely task of trying to reduce there mailboxes from nearly 12-14Gb a piece across 40 users!!!!


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