permanent errors were reported on my zpool today.
status: One or more devices has experienced an error resulting in data
corruption. Applications may be affected.
action: Restore the file in question if possible. Otherwise restore the
entire pool from backup.
scan: none requested
NAME STATE READ WRITE CKSUM
seagate3tb ONLINE 0 0 28
sda ONLINE 0 0 56
errors: Permanent errors have been detected in the following files:
Edit: I'm sure sure if those
CKSUM values are accurate. I was redacting data and may have mangled those by mistake. They may have been 0. Unfortunately, I can't find a conclusive answer in my notes and the errors are resolved now so I'm not sure, but everything else is accurate/reflects what zpool was reporting.
/mnt/seagate3tb/Install.iso is one example file reported as having a permanent error.
Here's where I get confused. If I compare my "permanently errored"
Install.iso against a backup of that exact same file on another filesystem, they look identical.
cmp /mnt/seagate3tb/Install.iso /mnt/backup/Install.iso
diff /mnt/seagate3tb/Install.iso /mnt/backup/Install.iso
The files seem to be identical. What's more, the file works perfectly fine. If I use it in an application, it behaves like I'd expect it to.
As the docs state:
Data corruption errors are always fatal.
But based on my rudimentary file verifications, I'm not sure I understand the definition of
status: One or more devices has experienced an error resulting in data corruption. Applications may be affected.
action: Restore the file in question if possible. Otherwise restore the entire pool from backup.
Maybe I'm missing something, but the file seems perfectly fine as far as I can tell, and does need any restoration nor does it show any corruption, despite the reccomendation from ZFS.
What is the permanent error with the file? Is there some lower level issue with the file that's just not readily apparent to me? If so, why would that not be detected by a
shasum as a difference in the file?
From a layperson's perspective, I see nothing to indicate any error with this file.