btrfs_device_flush_errors.md 2.2 KB
Understand the alert
This alert indicates that BTRFS flush errors have been detected on your file system. If you receive this alert, it means that your system has encountered problems while flushing data from memory to disk, which may result in data corruption or data loss.
What is BTRFS?
BTRFS (B-Tree File System) is a modern, copy-on-write (CoW) file system for Linux designed to address various weaknesses in traditional file systems. It provides advanced features like data pooling, snapshots, and checksums that enhance fault tolerance.
Troubleshoot the alert
- Verify the alert
Check the Netdata dashboard or query the monitoring API to confirm that the alert is genuine and not a false positive.
- Review and analyze syslog
Check your system's /var/log/syslog or /var/log/messages, looking for BTRFS-related errors. These messages will provide essential information about the cause of the flush errors.
- Confirm BTRFS status
Run the following command to display the state of the BTRFS file system and ensure it is mounted and healthy:
sudo btrfs filesystem show
- Check disk space
Ensure your system has sufficient disk space allocated to the BTRFS file system. A full or nearly full disk might cause flush errors. You can use the df -h command to examine the available disk space.
- Check system I/O usage
Use the iotop command to inspect disk I/O usage for any abnormally high activity, which could be related to the flush errors.
sudo iotop
- Upgrade or rollback BTRFS version
Verify that you are using a stable version of the BTRFS utilities and kernel module. If not, consider upgrading or rolling back to a more stable version.
- Inspect hardware health
Inspect your disks and RAM for possible hardware problems, as these can cause flush errors. SMART data can help assess disk health (smartctl -a /dev/sdX), and memtest86+ can be used to scrutinize RAM.
- Create backups
Take backups of your critical BTRFS data immediately to avoid potential data loss due to flush errors.