A local backup task failed. How do I resolve this?

Cause

The number of open files for the process exceeded the limit.

Log in to the local backup server and run the following command to check the connection count:
```
[root@localhost ~]# lsof -p `pgrep zstore`|wc -l
```
The max open files limit is 4096. If the returned connection count exceeds 4096, the process has exceeded its open file limit.
Run the following command to restart the zstore service and release connections:
```
[root@localhost ~]#  systemctl restart zstack-imagestorebackupstorage.service
```