Help!!!! Secondary Failures: MEM CRITICAL - system memory usage: 100%
 

I ran dmesg and I got these messages

[2491524.886272] e1000e: enp3s0 NIC Link is Down
[2491531.299456] e1000e: enp3s0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
[2491578.392100] e1000e: enp3s0 NIC Link is Down
[2491578.396627] e1000e: enp3s0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
[2491672.553447] systemd-journald[20280]: Failed to set file attributes: Operation not supported
[2491918.595118] e1000e: enp3s0 NIC Link is Down
[2491918.596567] e1000e: enp3s0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
[2491936.639172] systemd-journald[20280]: Failed to set file attributes: Operation not supported
[2492211.552366] systemd-journald[20280]: Failed to set file attributes: Operation not supported
[2492486.933218] systemd-journald[20280]: Failed to set file attributes: Operation not supported


What does this mean and how can I go about fixing it. I'm running Ubuntu on a Oracle VM virtualbox 64-bit.

You don't tell us what versions of anything you're using, and don't really say how your subject line about no memory ties in to what you posted from dmesg. The error is very clear...it's telling you that you're out of memory. Since you're using Virtualbox...increase the amount you have allocated to that machine.

You may also need to use facilities such as ulimit to restrict how much memory a process is allowed to use. (The limit should be large enough that in ordinary operation the process would never run into it ... enabling you to detect a bug before it brings the system down. Linux will start refusing to grant more memory ... "malloc" calls will begin to fail.)

If this began to happen recently, look for recent changes: software that just got installed, or maybe an internal application that just got updated (thereby introducing a bug). Processes that "run away," or that "fork-bomb" the system, or that otherwise are not properly designed to handle the loads that they are actually seeing, can all produce this kind of behavior. (I once saw a bug where a server process inadvertently began "talking to itself," and it didn't have controls on the number of simultaneous connections it would accept. The process effectively fork-bombed itself.) That sort of thing . . .