Recently I had a confusion with regards to the volume space breakup. where I was not able to find how much space I have on the volume for the data or snapshot to grow. May be you will end in a similar situation and this explanation helps.
When I executed the command df-g the output was as below.
cluster::> df -g volume1
Filesystem total used avail capacity Mounted on Vserver
/vol/volume1/ 560GB 436GB 123GB 78% /volume1 vserver1
/vol/volume1/.snapshot 240GB 504GB 0GB 210% /volume1/.snapshot vserver1
2 entries were displayed.
cluster::> vol autosize -vserver vserver1 -volume volume1
Volume autosize is currently ON for volume “vserver1:volume1”.
The volume is set to grow to a maximum of 800g in increments of 20g when the volume used space is above 95%.
Volume autosize for volume ‘vserver1:volume1’ is currently in mode grow.
if we look closely the volume space utilized was 436GB out of 560GB
and the snapshot space utilization is 504GB out of 240GB. When we sum up the space utilization of volume with that of snapshot space utilization is (436+504)=940GB. Where the actual volume size is 800gb max ( autosize for this volume), which ideally cannot happen.
Lets break this:
when df-g is executed
/vol/volume1/ 560GB 436GB 123GB 78% /volume1 vserver1
the space consumed on the volume which is 436gb is not just the data space.it also includes the spillover snapshot space.
/vol/volume1/.snapshot 240GB 504GB 0GB 210% /volume1/.snapshot vserver1
let us calculate the snapshot spill over space :
504GB-240GB=264GB
now the data space can be calculated as below:
436GB-264GB=172GB
so how much is the data space we are left with at this situation?
Total volume space -(Dataspace+snapshotspace)
800-(174+504=676)=124GB
This is amount of space to which we can add data or snapshot.
Hope this helps, ask for more questions here.
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