Netbackup client version 7.6. Error

Hi

We are using Netbackup client version 7.6. I am responsible for client troubleshooting. I am getting below errors.

Please guide me to troubleshoot from client side.

1. Backups are failing with status 50 ERR-Unable to backup System state or shadow copy 

2. Backup failed with status 24 - sock write failed

3. Backup failed for server with status 156. The VSP cache is may be full.

4. The Volume snapshot that occurs to facilitate open file backup has failed. This failure is often caused by the VSP/VSS cache file running out of allocated space.

5.  Backup failed for server with status 156. snapshot error.

6. Backups are failing with status 58- no connectiont to client.

7. Backup failed for server with status 23 soctet read failed