tricky-chrome-pfq just failed on HWTest provision:
https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8931376052812538352

A filesystem checksum fails. This appears similar to  crbug.com/898647 , but might not be related (the error details are different and the error does not occur on chromeos4-devserver2).

Reason:
Download and install failed from chromeos4-devserver7.cros.corp.google.com onto chromeos4-row2-rack3-host1: command execution error
  * Command: 
      /usr/bin/ssh -a -x  -o ControlPath=/tmp/_autotmp_qeFQX0ssh-master/socket
      -o Protocol=2 -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null
      -o BatchMode=yes -o ConnectTimeout=30 -o ServerAliveInterval=900 -o
      ServerAliveCountMax=3 -o ConnectionAttempts=4 -l root -p 22
      chromeos4-row2-rack3-host1 "export LIBC_FATAL_STDERR_=1; if type
      \"logger\" > /dev/null 2>&1; then logger -tag \"autotest\"
      \"server[stack::_revert_boot_partition|_run|run] -> ssh_run(/postinst
      /dev/sda3 2>&1)\";fi; /postinst /dev/sda3 2>&1"
  Exit status: 1
  Duration: 12.6224739552
  
  stdout:
  dm:dm bht[DEBUG] Setting block_count 317440
  dm:dm bht[DEBUG] Setting depth to 3.
  dm:dm bht[DEBUG] depth: 0 entries: 1
  dm:dm bht[DEBUG] depth: 1 entries: 20
  dm:dm bht[DEBUG] depth: 2 entries: 2480
  [1028/192020:ERROR:chromeos_verity.cc(280)] Filesystem hash verification failed
  [1028/192020:ERROR:chromeos_verity.cc(281)] Expected c80bd4547be2318ec62d708b0481f7bfa12f6eea != actual 814b3c6ac9344a48ae67649283061cb17a00c3b8