OCI: Instance unable to boot due to missing /etc/fstab file

Applies to

Oracle Cloud Infrastructure - Version N/A and later

Linux x86-64

Symptoms

The instance fails to boot normally and instead booted to maintenance mode and the root filesystem is mounted on /sysroot:

$ pwd
/sysroot

Cause

The /etc/fstab file is missing or empty. The system is booted to maintenance mode and the root filesystem is mounted as “read-only” on /sysroot

$ ls /sysroot/etc/fstab

Solution

1)Mount /sysroot as read-write using command below:

$ mount -o rw,remount /sysroot

2) Find out the underlying disks for the root filesystem and boot, boot/efi filesystems

$ /sysroot/usr/sbin/blkid
/dev/sda1: SEC_TYPE="msdos" UUID="3A04-27E1" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="37ce5210-0bdf-4316-badb-e1e509715029"
/dev/sda2: UUID="92f46bb4-0609-4149-8155-521cb271344d" BLOCK_SIZE="4096" TYPE="xfs" PARTUUID="9c504518-052f-4857-b9b9-6958dd401414"
/dev/sda3: UUID="Wtkskh-grVG-Pctx-lLOj-cMy7-I2vE-Br5Ijb" TYPE="LVM2_member" PARTUUID="e25e679a-cf9e-4f43-a85f-7c3c7d16f8ff"
/dev/mapper/ocivolume-root: UUID="a2c46b56-da9f-4829-be87-1d87b18c8aeb" BLOCK_SIZE="4096" TYPE="xfs"
/dev/mapper/ocivolume-oled: UUID="f9d1a191-470c-4bb2-ad65-58f895357a5d" BLOCK_SIZE="4096" TYPE="xfs"