Cluster nosync

Hello,

Since this morning, cluster display "nosync"

I show log and some message send "no space left on device.

My partition is full
/dev/mapper/pve-root 95G 95G 0 100% /

I find file about 99Go in /root/export-vm.tar

Could you tell me what happened ?
It is possible to delete file export-vm.tar ?

Thanks