Troubleshooting Exit Code -314 in Linux Edition

Summary

Exit Code -314 is a snapshot read error.
During backup, if the temporary snapshot file (COW file) cannot be maintained, the snapshot is discarded, and the backup fails with Exit Code -314.

Details

1) If physical memory usage exceeds 80% during the backup, it can affect system performance. Updates to the snapshot's COW file are halted, the snapshot is discarded, and the backup fails with Exit Code -314.

• The threshold cannot be changed.

Backup log when the error occurs (UTC+09:00).

05/07/2025 06:11:28.457 OOOW: No
05/07/2025 06:12:55.812 ReadFile failed Level = ERROR[5]
05/07/2025 06:12:55.812 Warning: less data read, (22185246720, 8388608 0)
...
05/07/2025 06:12:55.906 ###### something wrong during run pipe line
05/07/2025 06:12:55.906 Pipeline end, exit code: -314

System Log when an error occurs

May 7 15:12:55 alma89t07 kernel: datto: physical memory usage has exceeded 80% threshold. cow file update is stopped

Workaround

Increase physical memory
- Adjust the snapshot schedule to avoid large memory processes running at the same time.

- In Volume Backup, go to [2 Destination] → [Advanced Settings] → [Script], and add a script to stop/start memory-heavy processes before/after the snapshot.

 2) During the backup, if temporary snapshot files exceed the limit, frequent data writes to the source volume can cause the COW file to exceed its 10% size limit. This results in the snapshot being discarded, and the backup fails with Exit Code -314.

• The COW file size limit cannot be changed.

Backup Log when an error occurs (UTC+09:00)

05/07/2025 02:42:36.931 Pipeline start
05/07/2025 02:42:36.931 OOOW: No
05/07/2025 02:43:59.672 ReadFile failed Level = ERROR[5]
05/07/2025 02:44:01.497 Warning: less data read, (1644167168, 20250624 0)
...
05/07/2025 02:44:01.498 ###### something wrong during run pipe line
05/07/2025 02:44:01.498 Pipeline end, exit code: -314

System Log when an error occurs

May 7 11:43:59 rhel94efit01 kernel: datto: cow file '/.datto' max size exceeded (5372485632/5372483993): -27
May 7 11:43:59 rhel94efit01 kernel: datto: error writing cow data: -27
May 7 11:43:59 rhel94efit01 kernel: datto: error writing cow data and mapping: -27
May 7 11:43:59 rhel94efit01 kernel: datto: memory demands 1291845632, memory saved before crash 102400: -27
May 7 11:43:59 rhel94efit01 kernel: datto: error handling write bio: -27
May 7 11:43:59 rhel94efit01 kernel: datto: error handling write bio in kernel thread: -27
May 7 11:43:59 rhel94efit01 kernel: Buffer I/O error on dev datto1, logical block 1024, async page read

Workaround

If a large amount of data is written to the source volume during backup, adjust the schedule to prevent this from overlapping with the backup process.

• Go to Volume Backup → [2 Destination] → [Advanced Settings] → [Script], and add a script to stop/start processes writing large amounts of data before/after the snapshot.

For your reference

COW file generated during backup with AIP Linux Edition
https://actiphyhelp.zendesk.com/hc/en-us/articles/13451354234521-COW-file-generated-during-backup-with-AIP-Linux-Edition

Target Product

- ActiveImage Protector 2018/2022 Linux

(46616211758745)