Unable to create VM ?

[fpausp]

Cannot create a VM:

Formatting '/var/lib/vz/images/108/vm-108-disk-1.qcow2', fmt=qcow2  size=128849018880 encryption=off cluster_size=65536  preallocation='metadata' lazy_refcounts=off 
TASK ERROR: create failed - unable to open file '/etc/pve/nodes/prox3poe1/qemu-server/108.conf.tmp.139360' - Input/output error

After a reboot it works for a while to create a vm, I dont know how long until the error comes again ???