Azure VM-image-Ubntu 22.04 Data Disk Partition

Amila Goonatillake 0

I wanted to save my data in a separate azure data disk not in by default os disk. So I created a new data disk and wants to partition the disk and create file system and added a mount directory for the data disk I created. Also I added mount in persistent way in /etc/fstab file as well. But after I reboot the VM I cannot ssh or do any work because its giving error in the vm saying "VM agent is not ready state" .

So my question is why VM crashes after I just did partitioning steps for the newly created data disk attached ? Should I even have to do this kind of partition for azure data disk attached?

I'm using VM Image as 22_04-lts-gen2 Ubuntu and publisher is "Canonical"

vipullag-MSFT 24,206 Reputation points Microsoft Employee

2024-04-16T14:34:44.42+00:00

Hello Amila Goonatillake

Any update on the issue?

Just checking in to see if you got a chance to see previous response.

1 answer

vipullag-MSFT 24,206 Reputation points Microsoft Employee

2024-04-15T05:58:39.71+00:00

Hello Amila Goonatillake

Welcome to Microsoft Q&A Platform, thanks for posting your query here.

Ubuntu 22.04 LTS is a supported image on Azure.

The error message "VM agent is not ready state" that you shared, indicates that the VM agent is not running or not in a ready state. It could be due to some misconfiguration or issue with the VM. You can try restarting the VM to see if it resolves the issue. If the issue persists, you can check the VM logs to identify the root cause of the issue.

Partitioning the disk and creating a file system is a common practice when you want to use a data disk in Linux VMs. However, it is not necessary to partition the disk and create a file system if you are using Azure Managed Disks. Azure Managed Disks are already partitioned and formatted with a file system, so you can directly use them without any additional configuration.

Few Troubleshooting steps:

-When you modify the /etc/fstab file to include entries for mounting disks, it's essential to ensure that the entries are correct and won't cause issues during boot. Mistakes in fstab entries can lead to boot failures or unexpected behavior. Double-check your fstab entries to ensure they are correct.

-Consider whether manual partitioning of the data disk is necessary for your use case, and if not, try attaching the disk without partitioning it.

Hope this helps.
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Amila Goonatillake 0 Reputation points

2024-04-17T03:53:17.0166667+00:00

hi @vipullag-MSFT thanks for your reply with details. Yes I created "azurerm_managed_disk" resource by using terraform and when I execute "df -h" after attaching the disk , the new disk (sdc) not showing because I think that newly created data disk "sdc" is not having a file system nor a mountpoint mounted on it, by default ? But after I execute "lsblk" command sdc disk is showing.

So in this case should I create a new directory and mount it as a mountpoint to the new disk "sdc" ? of course after creating a file-system on the new disk as well ? But yeah as you said after I did the persistent mount with /etc/fstab file then after reboot VM agent get crashed.

Inside /etc/fstab file I used normal way of an disk entry such as below:

My_new_disk_UUID New_Disk_Partition_name New_Directory_Mount_Point file_type defaults 0 0

UUID=6a60524d-061d-454a-bfd1-38989910eccd /dev/sdc1 /home/user1/new_directory ext4 defaults 0 0

Amila Goonatillake 0 Reputation points

2024-04-17T03:57:43.8966667+00:00

hi @vipullag-MSFT I put my answer today, did you get my answer ? thanks

vipullag-MSFT 24,206 Reputation points Microsoft Employee

2024-04-17T04:27:01.5166667+00:00

Hello Amila Goonatillake

Thanks for responding back and sharing the details.

Yes, you are correct. If the newly created data disk is not showing up when you run the df -h command, it is likely that the disk does not have a file system or a mount point mounted on it. You can create a new directory and mount it as a mount point to the new disk "sdc" after creating a file system on the new disk.

After creating the file system, you can create a new directory and mount it as a mount point to the new disk

This will mount the new disk to the "new_directory" directory. You can then use the df -h command to verify that the new disk is mounted correctly.

Once you've confirmed the disk mounts correctly, you can add an entry to /etc/fstab to ensure it mounts automatically on boot. The entry should include the UUID of the disk, the mount point, filesystem type, and mount options.

Regarding the issue with the VM agent crashing after adding a persistent mount in the /etc/fstab file, it is possible that there is an issue with the configuration of the mount point. You can try removing the entry from the /etc/fstab file and rebooting the VM to see if the VM agent starts up correctly. If the VM agent starts up correctly, you can try adding the entry back to the /etc/fstab file and rebooting the VM again to see if the issue persists.

Based on the example fstab entry you provided, it seems there might be a misunderstanding of how to format the entry:

UUID=6a60524d-061d-454a-bfd1-38989910eccd /dev/sdc1 /home/user1/new_directory ext4 defaults 0 0

In this entry, /dev/sdc1 should not be present because you're already using the UUID to identify the disk. The correct entry should look like this:

UUID=6a60524d-061d-454a-bfd1-38989910eccd /home/user1/new_directory ext4 defaults 0 0

Make sure to replace 6a60524d-061d-454a-bfd1-38989910eccd with the actual UUID of your disk.

After correcting the fstab entry, you can try rebooting the VM to see if the issue with the VM agent crashing persists.

Hope this helps.

Amila Goonatillake 0 Reputation points

2024-04-18T14:00:31.1733333+00:00

hi @vipullag-MSFT thanks for your quick reply with in-detail. Yes before the reboot and after I did all the mounting stuff correctly df-h showing the mountpoint as it should be. But yes I think maybe I missed something in /etc/fstab file. I actually now working on some other project. So I will do the needful again in a new VM and get back to you in 1 week of time. Thanks a lot for your follow-ups. I will reply you soon as possible with an update.

vipullag-MSFT 24,206 Reputation points Microsoft Employee

2024-04-19T04:09:55.2033333+00:00

Hello Amila Goonatillake

Thanks for responding back with update.
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