Why aren't Azure Linux VM's keeping time sync with host?

Question

Using Ubuntu 12.04 VM's built last year on Azure. They only seem to get proper time on boot, and drift about a second a day. Is this a normal issue for Azure VM's? I know VM time drift is normal but thought Linux VM's in Azure (Hyper-V) get regular time sync from the host via integration services.

Solution 1

The OS usually only reads the (emulated) hardware clock upon boot, and then the clock is maintained with an interrupt timer. This is not a perfect time source, of course, and therefore you have to use NTP software to keep it accurate.

Solution 2

This is expected because Hyper-V's clock sync does not necessarily continue to discipline the clock after boot up - see one of the answers on Timesync on HyperV with CentOS 6.2 for details.

Solution 3

Seems others have this issue, even in Windows VM Roles. Once a week is causing too much time drift so I guess manual setting daily or less is indeed in order:

https://stackoverflow.com/questions/6186776/how-to-validate-local-vm-clock-with-ntp-on-windows-azure

Comments

[Anon]

The whole "Large clock drift with Linux Hyper-V guests" is a well discussed issue (but strangely little concrete information other than use ntpd/chrony). See serverfault.com/q/523389 for details.

[Igor Gatis]

Does this problem still occur as of today?

[Bret Fisher]

That question was 4 years ago, I have no idea now.

[Bret Fisher]

sorry, you're just repeating what I've said in my question "VM time drift is normal but thought Linux VM's in Azure (Hyper-V) get regular time sync..."

[Bret Fisher]

The question isn't that a VM may drift, but rather why is Azure time sync not keeping these VM's in check.

[Halfgaar]

Are you sure that is supposed to happen? AFAIK, the VM is on it's own when it comes to the clock.

[David Makogon]

VM Roles are not supported anymore (and haven't been for a long time), and that particular SO post is over 2 years old.