The volume server views summed the logical size of the volumes into
DiskUsage while DiskCapacity came from the filesystem statfs size. On a
compressing filesystem the logical sum exceeds the physical capacity, so
the server details popup derived a negative available space and rendered
it as "NaN undefined".
Pair each disk's capacity with the usage measured the same way, using the
statfs numbers the volume server already heartbeats, as CollectTierStats
does. Volume servers without statfs numbers keep the previous slot-based
capacity and logical bytes, and EC shard bytes are only counted there
instead of on top of the filesystem usage.
Mohd Quamar Tyagi
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