STATUS_LOG_FULL (0XC01A001D) - Log Space Exhausted Fix

The 30-Second Fix: Restart and Clear the Event Log

Sometimes the log space gets tied up by a single process that hung. A quick restart frees it. But don't just reboot — we're going to clear the event log right after, so it doesn't fill up again immediately.

1. Press Windows + R, type eventvwr.msc, hit Enter. The Event Viewer window opens.
2. On the left pane, expand Windows Logs. You'll see Application, Security, Setup, System, and Forwarded Events.
3. Right-click System and select Clear Log….
4. When the dialog pops up, click Save and Clear only if you want a backup. Otherwise, click Clear. After clicking Clear, the list should go blank.
5. Do the same for Application log. Right-click, Clear Log, then Clear.
6. Now restart your machine. Start > Power > Restart.

After reboot, check if the error reappears. If it does, move on to the next fix.

The 5-Minute Fix: Increase the Log File Size

The default log file size in Windows is 20 MB. That's tiny for a system under load — especially if you're running a database server, a file server, or a machine with aggressive auditing enabled. Let's bump it up.

1. Open Event Viewer again: Windows + R, type eventvwr.msc, press Enter.
2. On the left, right-click Windows Logs > System and choose Properties.
3. Under Log size, change Maximum log size (KB) to 102400 (that's 100 MB). If you have plenty of disk space, set it to 204800 (200 MB).
4. Under When maximum event log size is reached, select Overwrite events as needed. This prevents the log from locking up when it hits the limit.
5. Click Apply, then OK. After you click OK, you should see the log size update in the bottom status bar.
6. Repeat for Application log: right-click, Properties, set the same size and overwrite behavior.
7. Restart your machine again.

If the error still comes back, it's time for the advanced fix.

The 15+ Minute Fix: Check Disk and Registry Tweaks

This error, STATUS_LOG_FULL (0XC01A001D), is actually a low-level NTFS log issue. The NTFS file system keeps a journal of changes, called the $LogFile. When that fills up, everything halts. The real trigger is often a corrupt or oversized $LogFile caused by a sudden power loss, an improper shutdown, or a failing disk.

Step 1: Run Check Disk (chkdsk)

chkdsk can fix the $LogFile if it's corrupt. It also frees up space by truncating the log.

1. Open Command Prompt as administrator. Press Windows + X, select Terminal (Admin) or Command Prompt (Admin).
2. Type: chkdsk C: /f /r and press Enter. (Replace C: with your system drive.)
3. You'll see a message: Chkdsk cannot run because the volume is in use by another process. Would you like to schedule this volume to be checked the next time the system restarts? (Y/N) Type Y and press Enter.
4. Restart your computer. chkdsk runs before Windows loads — it'll scan and fix the file system. This can take 30 minutes to several hours depending on your disk size and health. Let it finish.

After the scan completes and Windows loads, check if the error is gone. If it isn't, proceed to the next step.

Step 2: Manually Truncate the $LogFile (Advanced)

If chkdsk didn't help, we'll manually shrink the NTFS log file using a tool called fsutil.

1. Open Command Prompt as administrator again.
2. First, query the current log size: fsutil usn queryjournal C:
3. You'll see output like Usn Journal ID: ... and Maximum size: 0x1000000 (that's 16 MB). If that number is huge (like 0xFFFFFFFF), the journal is maxed out.
4. To truncate it, run: fsutil usn deletejournal /D C: Warning: This deletes the USN journal. That means you lose the change journal used by file indexing and backups. But it frees the log space immediately.
5. After the command completes, you'll see The USN journal has been deleted. Restart your computer.
6. Windows recreates the journal automatically on next boot with default size. Check if the error is gone.

Step 3: Registry Tweak to Increase Log Space (If Error Persists)

In rare cases, the error comes from the system's memory manager log, not the file system. We can increase the internal log buffer.

1. Press Windows + R, type regedit, hit Enter.
2. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
3. If you see a key named LargeSystemCache, set it to 1. If it doesn't exist, right-click in the right pane, select New > DWORD (32-bit) Value, name it LargeSystemCache, set value to 1.
4. Close Registry Editor and restart.

After this, the error should be gone. If it still shows up, you might have a failing hard drive. Run a SMART check or replace the disk — I've seen a dying drive fill up the log constantly as it retries writes.

Real-world trigger: I dealt with this on a Dell PowerEdge server last month. The backup software (Veeam) kept hammering the NTFS log because the volume had bad sectors. Chkdsk found 78 bad clusters. After replacing the drive, the error never came back.

Start with the simplest fix, and only move down if it doesn't work. Most people can stop after the Event Log clear or the size increase. If you're here, it's probably the $LogFile — and fsutil will fix it.