Troubleshooting

Troubleshooting

Triggering kdump Restart

# Write 1 to the sysrq file to enable the SysRq function. After this function is enabled, the kernel will respond to any operation.
echo 1 > /proc/sys/kernel/sysrq

# Make the system crash.
echo c > /proc/sysrq-trigger

Performing Forcible Restart

You can use either of the following methods to forcibly restart the OS:

Manually restart the OS.

reboot -f

Forcibly power on and off the OS through iBMC.

en-us_image_0000001372249333

Restarting the Network

openEuler uses NetworkManager to manage the network. Run the following command to restart the network:

systemctl restart NetworkManager

Repairing the File System

After the OS is forcibly powered off and then powered on, the file system may be damaged. When the OS is started, it automatically checks and repairs the file system. If the file system fails to be repaired, you need to run the fsck command to scan for and repair the file system.

# In this case, the system enters the rescue mode. Check which file system is damaged in the log.
journalctl -xb
# Check whether the partition has been mounted before the repair.
cat /proc/mounts
# Uninstall the directory.
umount xx
# If the directory cannot be uninstalled, kill the process that occupies the directory.
lsof | grep xxx
kill xxx
# Run the fsck command to rectify the fault. Enter yes or no when prompted.
fsck -y /dev/xxx

Manually Dropping Cache

# Different values of N can achieve different clearance purposes. According to the Linux kernel document, run the sync command before clearing data. (The drop operation does not release any dirty objects. The sync command writes all unwritten system buffers to drives, including modified inodes, delayed block I/Os, and read/write mapping files. In this way, dirty objects can be reduced so that more objects can be released.)
echo N > /proc/sys/vm/drop_caches

# Release the page caches.
echo 1 > /proc/sys/vm/drop_caches

# Release dentries and inodes.
echo 2 > /proc/sys/vm/drop_caches

# Release the page caches, dentries, and inodes.
echo 3 > /proc/sys/vm/drop_caches

Rescue Mode and Single-User Mode

Rescue mode
Mount the openEuler 22.03 LTS SP1 ISO image and enter the rescue mode.
1. Select Troubleshooting.
2. Select Rescue a openEuler system.
3. Proceed as prompted.
```
1)Continue

2)Read-only mount

3)Skip to shell

4)Quit(Reboot)
```
Single-user mode
On the login page, enter e to go to the grub page, add init=/bin/sh to the linux line, and press Ctrl+X.
1. Run the mount -o remount,rw / command.
2. Perform operations such as changing the password.
3. Enter exit to exit.

Bug Catching

Buggy Content

Bug Description

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Bug Type

Specifications and Common Mistakes

● Misspellings or punctuation mistakes;

● Incorrect links, empty cells, or wrong formats;

● Chinese characters in English context;

● Minor inconsistencies between the UI and descriptions;

● Low writing fluency that does not affect understanding;

● Incorrect version numbers, including software package names and version numbers on the UI.

Usability

● Incorrect or missing key steps;

● Missing prerequisites or precautions;

● Ambiguous figures, tables, or texts;

● Unclear logic, such as missing classifications, items, and steps.

Correctness

● Technical principles, function descriptions, or specifications inconsistent with those of the software;

● Incorrect schematic or architecture diagrams;

● Incorrect commands or command parameters;

● Incorrect code;

● Commands inconsistent with the functions;

● Wrong screenshots.

Risk Warnings

● Lack of risk warnings for operations that may damage the system or important data.

Content Compliance

● Contents that may violate applicable laws and regulations or geo-cultural context-sensitive words and expressions;

● Copyright infringement.

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