And, by the way, this very same technique applies to network transfers (think VDI!) and even local RAM. Windows Server 8 saves local memory by finding duplicate information and getting rid of it.

After decades of putting up with Chkdsk, which essentially takes your servers offline for hours in case of a hard drive disaster or crash, Microsoft came up with a major revamp of the infamous disk checker tool. ChkDsk offers (finally!) an online scan and corruption logging mechanism. It marks defective clusters and files during runtime and cleans them later using a technique called "Spot Repair," which shows itself both through the UI (Server Manager, Action Center) and PowerShell.

The "Spot Verifier Service," which is part of the Windows 8 client as well, attempts to repair disk issues on-the-fly. If that's not possible, maybe due to a more critical file system error, admins have the chance to attempt and perform an instant repair using the "spotfix" parameter or schedule a chkdsk for later.

If possible, chkdsk simply eliminates the errors that the "Online scan" feature logged, which takes only a few seconds or minutes compared to the hours that you'd have to wait on Windows Server 2008 R2.