Hey everyone! I'm trying to integrate Btrfs with Nagios or Icinga and I'm running into some challenges. Nagios has a solid plugin for checking regular file systems like XFS, but I'm struggling to find something similar for Btrfs that gives accurate disk check results. I've found one plugin, but it's showing a discrepancy of about 3-5%, which is a dealbreaker for me. Has anyone out there found a good solution, or does anyone have any code examples that could help? I'm really hoping for some suggestions!
3 Answers
Can you clarify where you're seeing the discrepancy? For instance, what tools are you using that report the 3-5% difference? Keep in mind, things like deduplication, compression, or snapshots can affect how different tools report disk utilization, leading to confusion. Getting a precise view of space utilization on advanced filesystems like Btrfs can be tricky—a lot of the results might technically be correct but show different data based on what aspects they're measuring.
It's pretty cool someone is using Btrfs in production! However, the discrepancy you’re noticing likely has to do with Btrfs's CoW feature, and these differences can be pretty tough to eliminate altogether.
You might want to consider writing a simple shell script to handle your checks. It could allow you to customize the way you gather and report data directly from the Btrfs filesystem.
That's true, but with Btrfs being Copy-on-Write (CoW), I'm worried about getting accurate readings. If anyone has tackled that issue before, I'd love to hear how!
That's exactly what I was thinking! I was hoping to create a script that would check disk usage and send back exit codes at 80% for warnings and 90% for critical levels, but I'm not sure how reliable that will be.