Azure Site Recovery

Question

Azure Site Recovery

jihad majed 520

i have issue related to hyper v to azure replication when i selecting vm to replicate as shown below:

User's image

the operating os disk for generation 2 virtual machine exceed the azure site recovery size limit 300gb

Suchitra Suregaunkar 170 Reputation points Microsoft External Staff Moderator

2025-07-23T12:19:14.3166667+00:00
Hello jihad majed,

Thank you for posting your query on Microsoft Q&A.

The error that you are seeing – “The operating OS disk for Generation 2 virtual machine exceeds the Azure Site Recovery size limit of 300 GB” which is due to a current limitation in Azure Site Recovery when replicating Generation 2 VMs from Hyper-V.

Right now, if a Gen 2 VM (which uses UEFI boot) has an OS disk larger than 300 GB, Azure Site Recovery can’t replicate it.

It’s a known limitation from Microsoft’s side.

Here is the referral document: https://learn.microsoft.com/en-us/azure/site-recovery/hyper-v-deployment-planner-analyze-report

Further workarounds are:

1.Shrink the OS Disk Size: Reduce the OS disk size to below 300 GB.

Convert to Generation 1 VM

Thanks,

Suchitra.
Suchitra Suregaunkar 170 Reputation points Microsoft External Staff Moderator

2025-07-28T07:04:50.27+00:00

Hello jihad majed

Just checking in to see if you had a chance to see the previous comment.

Kindly let us know if the provided details helps or you need further assistance on this issue.

Thanks,

Suchitra.

Accepted answer

0 additional answers

Your answer

Suchitra Suregaunkar 170 Reputation points Microsoft External Staff Moderator

2025-07-23T12:19:14.3166667+00:00

Hello jihad majed,

Thank you for posting your query on Microsoft Q&A.

The error that you are seeing – “The operating OS disk for Generation 2 virtual machine exceeds the Azure Site Recovery size limit of 300 GB” which is due to a current limitation in Azure Site Recovery when replicating Generation 2 VMs from Hyper-V.

Right now, if a Gen 2 VM (which uses UEFI boot) has an OS disk larger than 300 GB, Azure Site Recovery can’t replicate it.

It’s a known limitation from Microsoft’s side.

Here is the referral document: https://learn.microsoft.com/en-us/azure/site-recovery/hyper-v-deployment-planner-analyze-report

Further workarounds are:

1.Shrink the OS Disk Size: Reduce the OS disk size to below 300 GB.

Convert to Generation 1 VM

Thanks,

Suchitra.
Suchitra Suregaunkar 170 Reputation points Microsoft External Staff Moderator

2025-07-28T07:04:50.27+00:00

Hello jihad majed

Just checking in to see if you had a chance to see the previous comment.

Kindly let us know if the provided details helps or you need further assistance on this issue.

Thanks,

Suchitra.

Answer 1

Hello jihad majed,

Thank you for posting your query on Microsoft Q&A.

The error that you are seeing – “The operating OS disk for Generation 2 virtual machine exceeds the Azure Site Recovery size limit of 300 GB” which is due to a current limitation in Azure Site Recovery when replicating Generation 2 VMs from Hyper-V.

Right now, if a Gen 2 VM (which uses UEFI boot) has an OS disk larger than 300 GB, Azure Site Recovery can’t replicate it.

It’s a known limitation from Microsoft’s side.

Here is the referral document: https://learn.microsoft.com/en-us/azure/site-recovery/hyper-v-deployment-planner-analyze-report

Further workarounds are:

1.Shrink the OS Disk Size: Reduce the OS disk size to below 300 GB.

2.Convert to Generation 1 VM

To help the community find the right answers, please do mark the post which was helpful by clicking on Accept Answer. And, if you have any further questions do let us know.

Thanks,

Suchitra.

Share via

Azure Site Recovery

0 additional answers

Your answer