A new NTFS health model in Windows 8 and Windows Server 2012 monitors drives for corruption, repairs many issues while volumes remain online, and offers fast offline repairs with spotfix.
In the majority of cases, NTFS is able to self heal when a corrupt file is detected, while keeping the volume online. The number of issues that can be fixed online has increased in Windows 8 and Server 2012 and is further improved in Windows 8.1 and Server 2012 R2.
Windows 8 and Server 2012 introduce a new capability that allows the file system to verify whether an issue is caused by a transient memory error or whether there is genuine file corruption on the disk. When the file system driver detects corruption, it verifies whether the corruption is genuine using the new Spot Verifier service.
If the errors are verified to be genuine, an online scan of the volume catalogs the issues so that they can be fixed at a later point without scanning the entire volume offline. In Windows 8, chkdsk scans are automatically scheduled to be performed during a maintenance window, i.e. when there is low CPU and disk activity. When an offline chkdsk repair is required, users will be notified via the Action Center. In Windows Server 2012, administrators can choose to schedule scans at an appropriate time.
If an offline repair is required, chkdsk can perform a spotfix using the list of catalogued errors from the scan. This works much faster than in previous versions of Windows, where offline disk repair times were proportional to the number of files on the volume, and not to the number of corrupt files.
If a scan has identified that an offline repair is required, you can run a spotfix repair using the new chkdsk switch, where d: is the letter name assigned to the volume to be scanned:
chkdsk d: /spotfix
Additionally, while it shouldn’t be necessary, you can manually force a volume scan:
chkdsk d: /scan
If the volume being repaired contains the OS boot files, you will be asked to restart the operating system to complete the operation, but repairing data only volumes doesn’t require an OS restart. In Windows 8, users can reboot the OS to fix corruption errors logged during a scan on both data and system volumes.