PVE 4.2: drbd9 disk avail size question

[baudinpr]

Hi all,

I have a PVE 4.2 cluster with 2 nodes and DRBD9.
The drbdpool virtual group size is 7.10 Tb
I have 2 VMs, each with 2 raw ide disks of 100 and 1000 Gb, so the total used space for VMs should be 2200 Gb.
All drbd disks are UpToDate and all is working fine.

But the question is:
When I look at the summary tab of DRBD1 storage in Proxmox I see:
Size: 14.20 Tb (OK, I assume 7.10Tb x 2)
Used: 8.76 Tb (????)
Avail: 5.44. TB (????)

How Used and Avail is calculated ?

Many thanks for a reply.
Regards
Piero Baudino

 

[fabian]

the used space is calculated by taking the total space and subtracting the "free space", where free space is the maximum size a new volume with the given replication count could get at that moment. this calculation is always off, because the free space is only counted "once", but the total space is over all nodes/disks. this is a known problem.