EC2 Failing instance status checks
I hope most of the administrators may come across this issue in AWS ” EC2 Failing instance status checks” . Why this issue occurring ? Yes , there could be multiple reason for each operating system .
But one of the frequent reason would be Operating System fail to boot.
Remeber you are just moved the infrastructure into cloud , but still you are using same operating system and boot sequences.So we can always expect similar kind of boot issue like traditional environment.
- Check the instance console screen and log and see whether the operating system is completely booted or not.
- If it Linux based operating system troubleshooting the boot problem is very easy .Ex the boot issue may apper like below.
Checking all file systems.
[/sbin/fsck.ext4 (1) — /] fsck.ext4 -a /dev/xvda1
fsck.ext4: symbol lookup error: fsck.ext4: undefined symbol: set_com_err_gettext
**** An error occurred during the file system check.*
**** Dropping you to a shell; the system will reboot*
**** when you leave the shell.*
/dev/fd/9: line 2: plymouth: command not found
- To trouble shoot this issue first detach the volume from broken instance and attach to working instance.Then check the file system configuration files anc /etc/fstab entries.
- You can run fsck on it if needed to fix block level issues
- modify the Fstab file, specifically the 6th field. You can turn off the fsck on start boot
- Then attache disk back to actual instance and try to boot.
- Windows also same procedures , chkdisk , file system check etc.
General error mounting filesystems (Failed mount)
Another possible reason could be file system missing when booting . If you removed the disk outside operating system like in AWS console and if you try to boot , it will check in /etc/fstab and fail.
But for windows it will not make any major issue , it will just boot without specific disk ..
XENBUS: Timeout connecting to devices (Xenbus timeout)
the reasons due to any one of below
- The block device not is connected to the instance
- This instance is using a very old instance kernel