bad_blocks

Source code: bad_blocks.py

Tests a storage device by running the badblocks command.

Description

This test uses badblocks(8) command to search for badblocks on a device. By default the unused portion of the stateful partition is used (mode=stateful_partition_free_space). (For instance, on a device with a 32 GB hard drive, cgpt reports that partition 1 is about 25 GB, but the size of the filesystem is only about 1 GB. We run the test on the unused 24 GB.)

Alternatively one can specify the use of a file in the filesystem allocated by the test, or raw mode where a specific file/partition must be provided. (mode=file or mode=raw)

When mode=stateful_partition_free_space, unused portion after stateful partition must exist. An error message 'There is no unused space after stateful partition.' will be shown if it cannot find any extra space. (If you install the image by chromeos-install, by default, there will be no free space after stateful partition.)

Default Behavior

The test will use 1GB of unused portion of the stateful partition for testing by default. On most devices, badblocks takes ~0.5s/MB (for four passes). So the default setup will take about 9 minutes.

The test skips badblocks and only runs smartctl for SSD storage by default.

Test Procedure

This test does not require operator interaction. An UI will be shown to indicate the process of testing.

Dependency

This pytest depends on badblocks(8).

Examples

To run default test:

{
  "pytest_name": "bad_blocks",
  "label": "Bad Blocks",
  "related_components": [
    "test_tags.TestCategory.BRIDGE_PCIE_EMMC",
    "test_tags.TestCategory.STORAGE"
  ],
  "args": {
    "timeout_secs": 120,
    "log_threshold_secs": 10,
    "max_bytes": 1073741824
  }
}

To change the portion of disk to 2 GB:

{
  "pytest_name": "bad_blocks",
  "label": "Bad Blocks 2GB",
  "related_components": [
    "test_tags.TestCategory.BRIDGE_PCIE_EMMC",
    "test_tags.TestCategory.STORAGE"
  ],
  "args": {
    "timeout_secs": 120,
    "log_threshold_secs": 10,
    "max_bytes": 2147483648
  }
}

To force running badblocks:

{
  "pytest_name": "bad_blocks",
  "label": "Bad Blocks Force badblocks On SSD",
  "related_components": [
    "test_tags.TestCategory.BRIDGE_PCIE_EMMC",
    "test_tags.TestCategory.STORAGE"
  ],
  "args": {
    "timeout_secs": 120,
    "log_threshold_secs": 10,
    "max_bytes": 1073741824,
    "force_badblocks_on_ssd": true
  }
}

Troubleshooting

If the test image is installed by chromeos-install and pytest complains there’s no unused space to be checked, re-install the image via factory shim or netboot. You can find different ways to install images at here: https://chromium.googlesource.com/chromiumos/platform/factory/+/HEAD/README.md#Imaging-methods

Test Arguments

Name	Type	Description
mode	[‘file’, ‘raw’, ‘stateful_partition_free_space’]	(optional; default: <_TestModes.stateful_partition_free_space: 'stateful_partition_free_space'>) Specify which operating mode to use.
device_path	str, None	(optional; default: None) Override the device path on which to test. Also functions as a file path for file and raw modes.
max_bytes	int, None	(optional; default: None) Maximum size to test, in bytes.
max_errors	int	(optional; default: 20) Stops testing after the given number of errors.
timeout_secs	int, float	(optional; default: 10) Timeout in seconds for progress lines
extra_log_cmd	str, None	(optional; default: None) Extra command to run at start/finish to collect logs.
log_threshold_secs	int, float	(optional; default: 5) If no badblocks output is detected for this long, log an error but do not fail
log_interval_secs	int	(optional; default: 60) The interval between progress logs in seconds.
drop_caches_interval_secs	int	(optional; default: 120) The interval between dropping caches in seconds.
destructive	bool	(optional; default: True) Do desctructive read / write test. If set to False, the data will be kept after testing, but longer testing time is expected.
force_badblocks_on_ssd	bool	(optional; default: False) SSD will maintain bad blocks on their own and only expose good blocks so badblocks is not that useful. smartctl output is still useful. Set this to force running badblocks.