NFS exported directory is not showing as monitored disk in CDM probe

Products

• DX Unified Infrastructure Management (Nimsoft / UIM)

Issue/Introduction

On a Linux server (built as NFS Server) I have exported a local file system folder but I'm not able to see the file system in the available disks in the CDM probe. Why? 

The filesystem is showing in as output of: # showmount -e 

Environment

Release : UIM 20.4, CDM probe

Cause

Working As Designed

Resolution

Network File System (NFS) is a client/server file system cross-platform protocol used to export local file systems over the network so that clients can share directories and files with others over a network. 

The CDM probe disk monitoring does not show the shared drives (showmount -e) on the source but only the mounted volumes on the nfs client (where the drive is mounted).

 

Practical Example: 

We have 2 servers.

...37 (NFS Server)

...43 (NFS Client) 

 

If we share a folder "/mnt/backups" on 10.2xx.xx7.43  (NFS Server)

It will show as output of showmount -e

 

Now, If we mounted this NFS on the (NFS Client) 10.2xx.xx7.37 the shared folder from the NFS server will show as an available file system on the NFS Client (output of df -h)

 

The CDM deployed on the the NFS Client is showing the mount.  Not the server where the folder is shared. 

(The mount does not show on the server NFS)

 

Additional Information

The shared mounts are visible in the client and not on the server. When the share is missing from the client where it is mounted, the CDM probe will alarm. (The way the probe works is that we are checking a system call "getmntent()" which displays the mounted volumes and we compare it to the configured volumes. The probe can't determine if a filesystem is missing in the output because it was removed on purpose or if it is missing because there is some problem with the filesystem, so it would send the alarm simply because the filesystem is not present when the configuration indicates that it should be present).