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Restored disk on Windows Server 2003 marked as hidden or read-only

Restore a disk in WinServer 2003, and you may find it is now marked as hidden or read-only. This is because during a low-level restore or a hardware disk swap, the attribute flags on the disk are sometimes reset.

If you restore a disk on Windows Server 2003, you may discover that it has been marked as hidden or read-only, meaning you can't write or use the disk after you restart the computer.

According to Microsoft, what has happened is that the attribute flags on the disk have gotten reset. This can happen in either a low-level restore or a hardware disk swap.

The 'hidden' and 'read-only' attributes on Windows disks are controlled by flags saved on the disk as part of the configuration information. The flag values are cached when the disk is mounted. Until the system is restarted, it uses the cached flag values, which may not be the same as the values on the disk because of the restore or disk swap.

What makes this occurrence really mysterious is that when you use a utility such as Diskpart.exe to check the values of the flags, it returns the cached value, not necessarily what's on the disk.

To avoid the problem, Microsoft recommends that you reset any component to zero which does a restore involving either swapping disks or the on-disk data that contains the attributes after the restore is finished.

Microsoft also recommends resetting the following flags to 0 to make sure the on-disk and cached values are consistent:


Microsoft discusses this issue in a Knowledgebase article.

About the author: Rick Cook specializes in writing about issues related to storage and storage management.

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