STATUS_LOG_SECTOR_REMAPPED 0XC01A0003 – Fix the Storage

Cause #1: Failing Hard Drive with Bad Sectors

Let's cut to the chase. 0XC01A0003 means the NTFS log on your volume tried to write to a sector the drive already remapped. The disk's internal bad-sector table filled up, or the sector went bad after remapping. This is almost always a hardware issue – not a Windows bug or a driver problem.

I've seen this pop up on aging SAS drives in HP ProLiant servers, cheap SATA drives in domain controllers, and any storage that's been running hot for years. The trigger is often a heavy write workload – say, an Exchange database checkpoint or a large file copy to a volume with low free space.

Fix it now, don't wait. The drive will keep remapping sectors until it runs out of spare blocks. Then you get STATUS_LOG_SECTOR_READ_FAILURE or total volume failure. Here's the drill:

1. Check the drive's S.M.A.R.T. data. Use wmic diskdrive get status in an elevated command prompt. If it returns "Bad" or "Unknown", that drive is toast. Get a replacement ready.
2. Run chkdsk /r on the affected volume. This scans every sector and forces the drive to remap bad ones. Example: chkdsk D: /r. This will take hours on a large drive. Plan downtime.
3. Back up everything off that volume first – even data that looks fine. Bad sectors can spread corruption silently. Use robocopy or a proper backup tool.
4. Check the Windows System event log for Event ID 7 (disk timeout) or Event ID 137 (disk failure predicted). These confirm hardware failure.

If chkdsk /r completes without finding additional bad sectors, the error might not reappear for a while. But I'd still replace the drive. Remapped sectors are a yellow flag – you got lucky once.

Cause #2: Firmware or Driver Glitch on RAID Controllers

Less common, but I've seen this on Dell PERC H730 and H740 RAID cards with older firmware. The RAID controller reports a sector remap that Windows picks up as 0XC01A0003, but the disk itself is fine. The culprit is a firmware bug that mislabels read errors as remapped sectors.

Check for known issues. Dell, HP, and Lenovo all publish firmware release notes. Look for fixes mentioning "SCSI sense error" or "incorrect sector status". Update the controller firmware – not the drive firmware – if that matches.

Also, update the storage driver. On Windows Server 2016 and 2019, the built-in storport.sys driver usually works fine, but some OEM drivers are outdated. Go to your server vendor's support site, grab the latest storage driver, and install it. Reboot after.

One real-world example: HP ProLiant DL380 Gen10 with a Smart Array P408i controller. Firmware version 4.0 showed this error constantly on one volume. Upgrading to 4.10 fixed it entirely. The disks were fine – the controller was lying.

Cause #3: Corrupted NTFS Log File (Rare but Real)

If your disk passes chkdsk, S.M.A.R.T. is clean, firmware is current, and you still get 0XC01A0003, the log itself might be corrupted. This happens after a dirty shutdown or power loss on a volume with pending log writes. The log file ($LogFile) becomes inconsistent.

Fix: Force a log reset. Run chkdsk /f on the volume. This fixes file system metadata and rebuilds the log. Unlike chkdsk /r, /f doesn't scan sectors – it's faster. Use this sequence:

1. Open an elevated command prompt.
2. Run chkdsk /f X: (replace X with the drive letter).
3. You'll likely be prompted to schedule it on next reboot. Type Y and restart.
4. After reboot, check the volume. If the error is gone, you're set. If it comes back, go back to Cause #1.

Don't bother with fsutil dirty set – that only marks the volume dirty, it doesn't fix the log. chkdsk /f is the correct tool.

Quick-Reference Summary Table

Bottom line: If you see 0XC01A0003, assume the drive is dying until proven otherwise. I've lost count of how many sysadmins blamed Windows or the file system, only to have the disk die a week later. Check the hardware first, then work up the stack.