When the Proxmox API's meminfo/status payload omits Available, Buffers,
and Cached (common for QEMU guest-agent and node status responses), the
code derived 'available' from Free alone — producing used = Total-Free
which counts reclaimable page cache as used memory (e.g. 94% instead of
the correct 76%).
Guest path (deriveGuestMemInfoAvailable): return 0 when cache metrics
are completely missing and only Free is available, so resolveGuestStatusMemory
tries better sources: guest-agent /proc/meminfo file-read (returns
MemAvailable), RRD memavailable, or the linked host agent.
Node path (resolveNodeMemory): always try RRD memavailable when cache
metrics are missing, not only when effectiveAvailable == 0 — previously
a non-zero Free value blocked the RRD fallback.
Refs #1501
v5 modeled memory as used | cache | free (Memory.Cache, 'reclaimable
buff/cache') and the memory bar's tooltip carried a 'Shown in Proxmox'
row explaining why Pulse's percentage reads lower than the Proxmox UI's
cache-inclusive number — a recurring support question. The v6 rebuild
deleted the field from the backend model, so the split and the
reconciliation vanished product-wide. Flagged by the Proxmox overview
parity audit.
Backend: re-add Memory.Cache; split it out via a shared
splitReclaimableMemory helper at the node resolver (node status reports
truly-free directly) and the VM builder (when guest meminfo reported
free pages); transport as proxmox.memoryCache on unified resources
alongside swap/balloon; mock mode populates plausible cache for nodes
and VMs.
Frontend: cache prop on StackedMemoryBar with the v5 muted-amber
segment between active and balloon, tooltip rows for reclaimable cache,
truly-free Free (balloon-capped), and the 'Shown in Proxmox'
reconciliation; guest and node memory adapters normalize free to
truly-free at the boundary; guest and node drawers grow a Reclaimable
cache row; the Proxmox nodes table passes cache and node swap through.
rcourtman