Node Disqualified - Explanation?

This error could only suspend your node, but not disqualify.
So, please try this one:

docker logs storagenode 2>&1 | grep GET_AUDIT | grep failed | grep -v usedserialsdb

The storagenode is incompatible with NFS/SMB, as I said earlier. It’s not related to the latency, but to Linux implementation of SMB and specifically to NFS. And it’s proven as a way to disqualification or other problems: Topics tagged nfs

The iSCSI performs MUCH better: Search results for 'iSCSI' - Storj Community Forum (official)
However, it has issues as well: Topics tagged iscsi

Please, do not use any network attached storage, especially NFS or SMB and especially on Linux (for example, they have a not fully compatible SMB protocol).
Though the SMB could work in some circumstances (Windows server - Windows client, or local connection via CIFS/SMB), but the remote connected storage should be avoided as well.

No. The disqualification is permanent. But you can start a new node on the other disk (please, do not use network connected storage!).
Also, you can vote for the idea