This is the second time it has happened. I get a complaint that people aren't getting emails for their voicemails. I can access everything except System Parameters. I want to see the SMTP settings. When I double-click on System Parameters, OSDM freezes for 2-3 minutes, but I don't get any output. The first time this happened, I would get a Check Link error, and had to reset the whole cabinet. I've tried resetting the SVM from 2.1.6. The OSDM resides on a local server that I am accessing remotely, and the server's IP is whitelisted.

I don't know if it means anything, but the system alarm report shows "SVMi HDD Alarm C1-S05 00%" after a reset.

Remote reset system, but still can't access SVMi system parameters or activity log. Was able to telnet into SVMi to look at logs. All of the log entry timestamps are Jan 01 00:00:xx, except for the login that allowed me to see this, which was the correct t/d. In the logs, are the error "EXT3-fs warning: mounting fs with errors, running e2fsck is recommended." Today, I received a trouble complaint from the customer that you couldn't leave messages for x241. You could listen to the greeting, but then it would say thank you and hang up. I look and see no mailbox for x241. It's looking more and more like I need to replace the SVMi, but I would like to be sure there is not something else I should be looking at. I can do the e2fsck, but I'm not confident it will do anything or not do something bad.

Using wireshark, when I try to access System Parameters from OSDM, I see a successful login on port 21, but then a timeout, "could not establish connection," when trying to access data.

The connection timeout sounds like a whitelist issue.

E2fsck is just the Linux fine system checking program. Like chkdsk in windows.

Is that the mgmt whitelist in 5.13.11? I have the subnet entered as x.x.x.255. Does that need to be in DM whitelist as well? I get concerned that I'm going to lock myself out.

That's the one. Don't put anything in the dm whitelist.
I have a vague recollection of increased security in 4.9x or 5.01 where http to the mp and possibly telnet to the svmi are disabled by default.
Try searching for http in dm. I can't remember where it was you turned them or off (maybe 5.6.1)

Thank you for the warning. This system is on 4.80. I've been able to get to the SysParms and activity log in the past, so I think I'll cold boot the system. The worst that's happened, other than losing access to the higher level SVMi menus, is that mailboxes disappear. If I still can't get into it, I'll have to look at replacing the SVMi. I'd like to avoid that.