This bob-paladin run: 
https://luci-milo.appspot.com/buildbot/chromeos/bob-paladin/3836#

 Failed with BrowserConnectionGoneException while starting the browser backend.
 [stderr] rsync: write failed on "/usr/local/autotest/results/default/graphics_Idle/sysinfo/var/log/messages": No space left on device (28)
 [stderr] rsync error: error in file IO (code 11) at receiver.c(393) [receiver=3.1.2]
 post-test sysinfo error:
 Traceback (most recent call last):
   File "/usr/local/autotest/common_lib/log.py", line 25, in decorated_func
     fn(*args, **dargs)
   File "/usr/local/autotest/bin/site_sysinfo.py", line 366, in log_after_each_test
     collect_all=not test.success)
   File "/usr/local/autotest/bin/site_sysinfo.py", line 268, in run
     logdir_temp.run(log_dir)
   File "/usr/local/autotest/bin/site_sysinfo.py", line 92, in run
     % (" ".join(excludes), from_dir, log_dir, parent_dir))
   File "/usr/local/autotest/common_lib/utils.py", line 1025, in system
     stdout_tee=TEE_TO_LOGS, stderr_tee=TEE_TO_LOGS).exit_status
   File "/usr/local/autotest/common_lib/utils.py", line 754, in run
     "Command returned non-zero exit status")
 CmdError: Command <rsync --no-perms --chmod=ugo+r -a --safe-links --exclude=/log/**autoserv* /var/log /usr/local/autotest/results/default/graphics_Idle/sysinfo/var> failed, rc=11, Command returned non-zero exit status
 * Command: 
     rsync --no-perms --chmod=ugo+r -a --safe-links --exclude=/log/**autoserv*
     /var/log /usr/local/autotest/results/default/graphics_Idle/sysinfo/var
 Exit status: 11
 Duration: 57.642524004
 
 stderr:
 rsync: write failed on "/usr/local/autotest/results/default/graphics_Idle/sysinfo/var/log/messages": No space left on device (28)
 rsync error: error in file IO (code 11) at receiver.c(393) [receiver=3.1.2]
 child process failed

https://stainless.corp.google.com/browse/chromeos-autotest-results/229076959-chromeos-test/