prlctl commands hang and then fail with error when timeout is reached.
# prlctl list -a Login failed: Unable to connect to the server "localhost". An invalid response has been received from the server. Make sure that Parallels Server is running on the server "localhost" and is up to date and try again.
This issue might happen if some filesystem, where VMs or VM templates are registered, has become inaccessible, operations (such as
df) with its mount point hang endlessly:
[root@PCS1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 394G 10G 364G 3% / tmpfs 32G 5.2M 32G 1% /dev/shm /dev/sda1 2.0G 122M 1.8G 7% /boot /dev/mapper/vg_pcs1-lv_pstorage 3.2T 467G 2.6T 16% /pstorage /dev/mapper/vg_pcs1-lv_vz 40G 9.4G 29G 25% /vz /pstorage/cluster-mds/DiskDescriptor.xml 9.9G 335M 9.1G 4% /pstorage/cluster-mds/ploop_mds.img.mnt ^C
Usually it's NFS file system which stores VM templates. NFS mount point tend to be the most vulnerable and fragile:
[root@PCS1 ~]# mount | grep nfs 220.127.116.11:/mnt/cluster/PCS1 on /templates type nfs (rw,timeo=14,intr,addr=18.104.22.168)
In such cases you will find nfs-related errors in dmesg:
[root@PCS1 ~]# dmesg | grep nfs [10405249.292138] ct0 nfs: server 22.214.171.124 not responding, still trying [10405259.798122] ct0 nfs: server 126.96.36.199 not responding, still trying
Find the reason why operations with this mount point hang, fix the root cause. Often it's due to inaccessible NFS server.