The previous reconciliation logic (issue #1052) used per-dataset statfs
values for Total and Used. On Proxmox systems, statfs on a mounted
dataset (e.g. rpool/ROOT/pve-1) only reports that dataset's own usage,
completely missing zvols (VM disk images) and other datasets. This caused
storage bars to show ~0% usage (a few GB of OS files) when the pool
actually had terabytes of VM data allocated.
Fix: derive usable pool capacity from the ratio of dataset Free (usable
pool-available from statfs) to zpool Free (raw pool-available from zpool
list). This ratio converts raw zpool Size to usable total, and Used is
computed as Total - Free. This captures all pool consumers including
zvols, handles RAIDZ parity overhead and mirrors uniformly, and produces
correct usage percentages.
Verified with tests for RAIDZ, mirrors, and both with zvols present.
For RAIDZ pools, zpool ALLOC includes parity overhead, but users expect
to see actual data usage. Now using dataset Used value (from statfs)
when RAIDZ is detected, matching the existing fix for total capacity.
Fixes the second part of #1052 where used capacity was inflated.
For RAIDZ/mirror pools, zpool list SIZE reports raw capacity (sum of
all disks), but users expect usable capacity (accounting for parity).
The dataset stats from statfs give the correct usable capacity.
Now uses dataset Total when it's smaller than zpool Size, indicating
RAIDZ/mirror overhead.
Related to #1052
Enhanced zpool binary lookup to try common paths when exec.LookPath fails.
This fixes issue #718 where TrueNAS SCALE reports inflated storage because
the agent runs with a restricted PATH that doesn't include /usr/sbin.
Changes:
- Added findZpool() helper that tries common paths like /usr/sbin/zpool,
/sbin/zpool, /usr/local/sbin/zpool for TrueNAS/FreeBSD/Linux systems
- Added commonZpoolPaths variable listing typical zpool locations
- Added tests for the new findZpool function
This ensures zpool list is used for accurate pool-level capacity instead
of falling back to dataset-level summation.
