Linux Instance Failed Status Checks

Review status check information

Solution:

• Check instance status using AWS CLI:
Copy

aws ec2 describe-instance-status --instance-ids i-xxxxxxx

• Review CloudWatch metrics for instance health.

Retrieve the system logs

Solution:

• Get logs via AWS CLI:
Copy

aws ec2 get-console-output --instance-id i-xxxxxxx

• Use the EC2 console to view logs.

Troubleshoot system log errors for Linux instances

Solution:

• Identify key error messages in system logs.
• Refer to AWS documentation for specific error resolutions.

Out of memory: kill process

Solution:

• Increase instance memory or swap space:
Copy

sudo dd if=/dev/zero of=/swapfile bs=1M count=1024
sudo mkswap /swapfile
sudo swapon /swapfile

ERROR: mmu_update failed (Memory management update failed)

Solution: Check instance memory and restart.

I/O error (block device failure)

Solution:

• Detach and reattach the root volume.
• Run `fsck` to check for disk errors.

I/O ERROR: neither local nor remote disk (Broken distributed block device)

Solution: Check disk attachments in EC2 console.

request_module: runaway loop modprobe

Solution: Upgrade to a newer kernel.

FATAL: kernel too old

Solution: Ensure AMI and kernel are compatible.

FATAL: Could not load /lib/modules or BusyBox

Solution: Reinstall missing kernel modules.

ERROR Invalid kernel (EC2 incompatible kernel)

Solution: Boot into a compatible kernel.

fsck: No such file or directory while trying to open...

Solution: Run `fsck` on the correct device.

General error mounting filesystems (failed mount)

Solution: Ensure `/etc/fstab` has correct entries.

VFS: Unable to mount root fs on unknown-block

Solution: Check boot disk UUID.

Error: Unable to determine major/minor number of root device...

Solution: Verify correct device mapping.

XENBUS: Device with no driver...

Solution: Rebuild Xen-based kernel.

... days without being checked, check forced

Solution: Run `fsck` to resolve forced file system check.

fsck died with exit status...

Solution: Attach disk to another instance and repair.

GRUB prompt (grubdom>)

Solution: Reinstall GRUB and update bootloader.

Bringing up interface eth0: Device eth0 has different MAC address than expected, ignoring.

Solution: Update MAC address in `/etc/udev/rules.d/70-persistent-net.rules`.

Unable to load SELinux Policy. Machine is in enforcing mode. Halting now.

Solution: Boot into permissive mode and fix SELinux policy.

XENBUS: Timeout connecting to devices

Solution: Restart instance or detach and reattach disk.