I have some automated test runs that are doing an ssh to a nexus7, dist-upgrade, reboot, then running some tests. After todays tests ran, I tried to connect remotely to one of the devices and though I could ping it, and it appeared to be up and running, I was not able to ssh in. Since they both did this, I didn't think it had anything to do with the individual tests I was running (smem and eventstat). I had someone who had access to the lab go check on it to confirm it was running, and restart it for me. After the restart I was able to ssh in just fine, and rerunning the tests didn't seem to effect this, however idling did. So to reproduce:
1. install openssh-server
2. ssh into the system
3. logout
4. wait a while (10-15 minutes seems to be sufficient)
5. try to ssh in again
This setup is relatively new, but I don't think I had this problem yesterday. On the off chance that one of the updates today might have caused it, here were the things that got updated from my test runner's log:
Get:1 http://ports.ubuntu.com/ubuntu-ports/ raring/main libgomp1 armhf 4.7.2-20ubuntu1 [25.2 kB]
Get:2 http://ppa.launchpad.net/utah/daily/ubuntu/ raring/main utah-common all 0.7ubuntu1-r810~raring1 [25.2 kB]
Get:3 http://ports.ubuntu.com/ubuntu-ports/ raring/main gcc-4.7-base armhf 4.7.2-20ubuntu1 [16.3 kB]
Get:4 http://ppa.launchpad.net/utah/daily/ubuntu/ raring/main utah-client all 0.7ubuntu1-r810~raring1 [79.3 kB]
Get:5 http://ports.ubuntu.com/ubuntu-ports/ raring/main libstdc++6 armhf 4.7.2-20ubuntu1 [271 kB]
Get:6 http://ports.ubuntu.com/ubuntu-ports/ raring/main cpp-4.7 armhf 4.7.2-20ubuntu1 [4,380 kB]
Get:7 http://ports.ubuntu.com/ubuntu-ports/ raring/main libgcc-4.7-dev armhf 4.7.2-20ubuntu1 [167 kB]
Get:8 http://ports.ubuntu.com/ubuntu-ports/ raring/main gcc-4.7 armhf 4.7.2-20ubuntu1 [5,015 kB]
Get:9 http://ports.ubuntu.com/ubuntu-ports/ raring/main libgcc1 armhf 1:4.7.2-20ubuntu1 [48.9 kB]
Get:10 http://ports.ubuntu.com/ubuntu-ports/ raring/main dconf-service armhf 0.15.2-0ubuntu5 [20.9 kB]
Get:11 http://ports.ubuntu.com/ubuntu-ports/ raring/main libdconf1 armhf 0.15.2-0ubuntu5 [22.6 kB]
Get:12 http://ports.ubuntu.com/ubuntu-ports/ raring/main dconf-gsettings-backend armhf 0.15.2-0ubuntu5 [14.0 kB]
Get:13 http://ports.ubuntu.com/ubuntu-ports/ raring/universe linux-image-3.1.10-9-nexus7 armhf 3.1.10-9.24 [5,706 kB]
Get:14 http://ports.ubuntu.com/ubuntu-ports/ raring/main alsa-utils armhf 1.0.25-4ubuntu1 [1,105 kB]
Get:15 http://ports.ubuntu.com/ubuntu-ports/ raring/main ubuntu-drivers-common armhf 1:0.2.75 [31.6 kB]
Get:16 http://ports.ubuntu.com/ubuntu-ports/ raring/main update-notifier armhf 0.130 [51.4 kB]
Get:17 http://ports.ubuntu.com/ubuntu-ports/ raring/main update-notifier-common all 0.130 [201 kB]
Get:18 http://ports.ubuntu.com/ubuntu-ports/ raring/main dconf-tools armhf 0.15.2-0ubuntu5 [63.2 kB]
Get:19 http://ports.ubuntu.com/ubuntu-ports/ raring/main libupower-glib1 armhf 0.9.19-1ubuntu4 [23.9 kB]
Get:20 http://ports.ubuntu.com/ubuntu-ports/ raring/main gnome-settings-daemon armhf 3.6.4-0ubuntu3 [405 kB]
Get:21 http://ports.ubuntu.com/ubuntu-ports/ raring/main sysvinit-utils armhf 2.88dsf-13.10ubuntu15 [54.0 kB]
Get:22 http://ports.ubuntu.com/ubuntu-ports/ raring/main sysv-rc all 2.88dsf-13.10ubuntu15 [44.1 kB]
Get:23 http://ports.ubuntu.com/ubuntu-ports/ raring/main initscripts armhf 2.88dsf-13.10ubuntu15 [27.9 kB]
Get:24 http://ports.ubuntu.com/ubuntu-ports/ raring/main python3-problem-report all 2.8-0ubuntu3 [10.6 kB]
Get:25 http://ports.ubuntu.com/ubuntu-ports/ raring/main python3-apport all 2.8-0ubuntu3 [88.5 kB]
Get:26 http://ports.ubuntu.com/ubuntu-ports/ raring/main apport all 2.8-0ubuntu3 [173 kB]
Get:27 http://ports.ubuntu.com/ubuntu-ports/ raring/main apport-gtk all 2.8-0ubuntu3 [9,922 B]
Get:28 http://ports.ubuntu.com/ubuntu-ports/ raring/main checkbox armhf 0.15.1 [1,413 kB]
Get:29 http://ports.ubuntu.com/ubuntu-ports/ raring/main checkbox-qt armhf 0.15.1 [67.2 kB]
Get:30 http://ports.ubuntu.com/ubuntu-ports/ raring/main libusbmuxd2 armhf 1.0.8-1ubuntu1 [13.5 kB]
Get:31 http://ports.ubuntu.com/ubuntu-ports/ raring/universe linux-headers-3.1.10-9 armhf 3.1.10-9.24 [11.7 MB]
Get:32 http://ports.ubuntu.com/ubuntu-ports/ raring/universe linux-headers-3.1.10-9-nexus7 armhf 3.1.10-9.24 [463 kB]
Get:33 http://ports.ubuntu.com/ubuntu-ports/ raring/main python-problem-report all 2.8-0ubuntu3 [10.6 kB]
Get:34 http://ports.ubuntu.com/ubuntu-ports/ raring/main python-apport all 2.8-0ubuntu3 [89.0 kB]
Get:35 http://ports.ubuntu.com/ubuntu-ports/ raring/main python-ubuntuone-storageprotocol all 4.1.90-0ubuntu1 [63.8 kB]
Get:36 http://ports.ubuntu.com/ubuntu-ports/ raring/universe ubuntu-defaults-nexus7 all 0.49 [9,018 B]
Get:37 http://ports.ubuntu.com/ubuntu-ports/ raring/main ubuntuone-client-gnome armhf 4.1.90-0ubuntu1 [16.7 kB]
Get:38 http://ports.ubuntu.com/ubuntu-ports/ raring/main upower armhf 0.9.19-1ubuntu4 [90.6 kB]
Get:39 http://ports.ubuntu.com/ubuntu-ports/ raring/main usbmuxd armhf 1.0.8-1ubuntu1 [33.5 kB]
Get:40 http://ports.ubuntu.com/ubuntu-ports/ raring/main xserver-common all 2:1.13.2-0ubuntu1 [32.9 kB]
Get:41 http://ports.ubuntu.com/ubuntu-ports/ raring/main xserver-xorg-core armhf 2:1.13.2-0ubuntu1 [1,264 kB]
Get:42 http://ports.ubuntu.com/ubuntu-ports/ raring/main xserver-xorg-video-radeon armhf 1:7.1.0-0ubuntu1 [134 kB]
Get:43 http://ports.ubuntu.com/ubuntu-ports/ raring/main xserver-xorg-video-ati armhf 1:7.1.0-0ubuntu1 [7,080 B]
Get:44 http://ports.ubuntu.com/ubuntu-ports/ raring/main xserver-xorg-video-nouveau armhf 1:1.0.6-0ubuntu2 [83.2 kB]
Get:45 http://ports.ubuntu.com/ubuntu-ports/ raring/main python-dirspec all 4.1.90-0ubuntu1 [6,886 B]
Get:46 http://ports.ubuntu.com/ubuntu-ports/ raring/main rhythmbox-ubuntuone all 4.1.90-0ubuntu1 [6,312 B]
Unfortunately, this is about all I can get at the moment since I don't currently have access to a local nexus7.
I have a local Nexus7 and I've been able to ssh in after hours of idle time. Even left it idling overnight and then ssh'd in in the morning in order to run updates.
Are there any specific steps you'd like me to try on my nexus7 in order to try to reproduce this?