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Azure Linux virtual machine not booting – disk issue

There could be cases that you have not configured the disk correctly inside a Linux azure virtual machine , or the disk mount point to change because of a disk increase. This circumstance will make your virtual machine fail and boot into emergency mode. In order to fix this issue you should first get a terminal windows on the Azure virtual machine as you cannot ssh. This can be done by selecting Help -> Serial Console

By checking the boot logs you can find the issue which in my case is the mounting of the data disk. The data disk is added as an entry on /etc/fstab but the mount point changed and Linux filesystem cannot locate it.

In order to resolve this issue you should mount the disk using the UUID to be 100% sure for the mount point. First locate the disk by using

fdisk -l

After locating the mount point run blkid command to find the UUID of the disk.

blkid

When you find the UUID use it in your /etc/fstab file instead of the mount point as shown below.

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Extend Raw Device Mapping Disk – virtual compatibility mode on VMware

You can follow the below procedure to extend an RDM disk with virtual compatibility mode on VMware. As described in the article attached on the bottom, you can accomplish that either by migrating the RDM or by shutting down the VM and performing the procedure below. The article implements the shut down way.

The first step is to extend the RDM disk from storage. Find the UUID descriptor and provide some additional space.

Then you need to locate the VMware disk that you want to extend and record the SCSI controller and SCSI ID because it is needed on a later stage.

on my case SCSI target is 8

Then you should delete the disk from virtual machine. You can also select (delete files from datastore) as only the RDM pointer will be deleted and not the actual disk data.

After that you should rescan storage devices and volumes on the ESXi host and locate if the device has identified the new capacity.

in my case the new storage capacity is 150G

Then edit virtual machine settings and select add new device that will be of type RDM Disk

The next dialog shows the new disk with the extended capacity.

Click OK and be careful in order to add the same SCSI ID and controller as previously.

Perform a rescan inside the Operating system and the capacity will be available for use

https://kb.vmware.com/s/article/1007021