The term Total and Free aren't super indicative of the spaces used by actual data or snapshots or metadata or at the application level and it does pop eyeballs when Total < Free.
The Output
root@test-pcl4004:~# kubectl openebs describe volume pvc-7d5944e9-XXXXXXXXXXXX
pvc-7d5944e9-XXXXXXXXXXXX Details :
-----------------
NAME : XXXXX
ACCESS MODE : ReadWriteOnce
CSI DRIVER : cstor.csi.openebs.io
STORAGE CLASS : XXXX
VOLUME PHASE : Bound
VERSION : 2.10.0
CSPC : XXXXXXXX
SIZE : 2.0GiB
STATUS : Healthy
REPLICA COUNT : 1
Portal Details :
------------------
IQN : iqn.2016-09.com.openebs.cstor:XXXX
VOLUME NAME : XXXX
TARGET NODE NAME : ABCD
PORTAL : XXXXX:3260
TARGET IP : XXXXX
Replica Details :
-----------------
NAME TOTAL USED STATUS AGE
XXXXXXXXXXXXXXXXXXXXXXXXXSDJHFSHGHGHXXXXXXXXXXXXXXX-YYYYYYYZZZ 33.6MiB 126.8MiB Healthy 67d1h
In the above output example, with the above headings it sort of becomes imperative that, Total = Free + Used, so in practice Used shouldn't exceed Total(unless Free is negative, which is absurd), but here the above values total means actual data written to disk & used means how much data got referenced.
At the nuts and bolts level, TOTAL comes from cvr.spec.capacity.Total which is USED property at the zfs level and used comes from cvr.spec.capacity.Used which is the logicalreferenced property at the zfs level.
Tl; dr: What needs to be done?
The underlying ZFS metric needs to be understood well enough(this isn't super straightforward)
The understanding of the above metric should be conveyed properly via simple English phrases/words, such as space used by data with compression, metadata, etc or something simple such as actual size on disk, logical size written by tenants, etc.
The term
TotalandFreearen't super indicative of the spaces used by actual data or snapshots or metadata or at the application level and it does pop eyeballs whenTotal < Free.The Output
In the above output example, with the above headings it sort of becomes imperative that,
Total = Free + Used, so in practiceUsedshouldn't exceedTotal(unlessFreeis negative, which is absurd), but here the above valuestotalmeansactual data written to disk&usedmeanshow much data got referenced.At the nuts and bolts level, TOTAL comes from
cvr.spec.capacity.Totalwhich is USED property at the zfs level andusedcomes fromcvr.spec.capacity.Usedwhich is thelogicalreferencedproperty at the zfs level.Tl; dr: What needs to be done?
space used by data with compression, metadata, etcor something simple such asactual size on disk,logical size written by tenants, etc.