Looking to restore guest files from a VM, any suggestions on what options to select?
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- What is the best method to restore files from a guest VM protected by VMware backups?
What is the best method to restore files from a guest VM protected by VMware backups?
- December 30, 2020
- 20 replies
- 2464 views

- Vaulter
- 1 reply
Best answer by Jordan
Hi Christine,
There are a number of options to get the best file restore from your VMware backups depending on the situation.
This video covers the scenarios in detail, including the requirements to perform this type of restore: How to recover files with the Virtual Server Agent for VMware
Let me know if you have any further questions at all.
Thanks
20 replies
- Vaulter
- 135 replies
- Answer
- December 31, 2020
Hi Christine,
There are a number of options to get the best file restore from your VMware backups depending on the situation.
This video covers the scenarios in detail, including the requirements to perform this type of restore: How to recover files with the Virtual Server Agent for VMware
Let me know if you have any further questions at all.
Thanks
- Commvault Certified Expert
- 40 replies
- January 4, 2021
Hi Christine,
what i have seen in the field, a restore of guest files direct in a vm is sometimes slower than a restore to an agent and based on the feedback from Jordan there are a lot of options to restore files.
try it on your environment to get a feeling for it!
Hope that helps you a little bit
Cheers Philipp
- Vaulter
- 1287 replies
- January 4, 2021
Hi Christine,
what i have seen in the field, a restore of guest files direct in a vm is sometimes slower than a restore to an agent and based on the feedback from Jordan there are a lot of options to restore files.
try it on your environment to get a feeling for it!
Hope that helps you a little bit
Cheers Philipp
Totally agree and my experience as well. There are protocol slowdowns by routing data through the ESXi webserver which is required for such restores. Almost always you can replicate this by using powercli and running the Copy-VMGuestFile function. This is essentially the same function that Commvault is calling, so its a good way to troubleshoot or validate the bottleneck with slow file restores directly to the guest VM. But lucky that there are multiple options to restore guest files, so if you have larger restores you can use another method!
- Commvault Certified Expert
- 87 replies
- January 10, 2021
It’s been discussed that the MS Windows MA’s running FR11.22 have a significant performance enhancement such that having an in-guest agent may no longer be required.
- Vaulter
- 1 reply
- January 11, 2021
Hello
One of the biggest bottlenecks when restoring guest files using the agentless method (uploading files directly to vCenter, and using VMTools to inject files into a guest VM), is that the copy-VMGuestFile API is single threaded, and requires a response from vCenter to confirm that the file has in fact been restored correctly.
This may not cause you much bottleneck with a small amount of files, but the more files restored, the more impact you will notice on the performance.
Alternatively, using an in-guest agent to restore, we can restore files using a multithreaded approach. As such, you will notice a large performance improvement when restoring a large amount of files.
- Vaulter
- 1287 replies
- January 11, 2021
It’s been discussed that the MS Windows MA’s running FR11.22 have a significant performance enhancement such that having an in-guest agent may no longer be required.
Not aware of any changes. I think there is some functionality change for AHV but not for VMware. Seems unlikely unless there is a new VMware API to consume - the functionality on the Commvault side is straightforward. I’ll ask around!
- Vaulter
- 1287 replies
- January 14, 2021
It’s been discussed that the MS Windows MA’s running FR11.22 have a significant performance enhancement such that having an in-guest agent may no longer be required.
Not aware of any changes. I think there is some functionality change for AHV but not for VMware. Seems unlikely unless there is a new VMware API to consume - the functionality on the Commvault side is straightforward. I’ll ask around!

- Social Yottabyte
- 74 replies
- January 14, 2021
Looking to restore guest files from a VM, any suggestions on what options to select?
Look at it depending on how big the VM is ( I think) the best approach. If you have a 80gb VM you need files off of its easy to restore the vm files or sometimes the live vm. IF you have a 10tb VM, its easier and faster to restore the drive to another vm and just transfer it. Again this is simply suggestion and my opinion. I have found this to be a good rule of thumb when restoring files from a vm.
- Social Yottabyte
- 74 replies
- January 14, 2021
It’s been discussed that the MS Windows MA’s running FR11.22 have a significant performance enhancement such that having an in-guest agent may no longer be required.
Not aware of any changes. I think there is some functionality change for AHV but not for VMware. Seems unlikely unless there is a new VMware API to consume - the functionality on the Commvault side is straightforward. I’ll ask around!

Thats good to know.
- Byte
- 141 replies
- January 25, 2021
Hi Christine,
what i have seen in the field, a restore of guest files direct in a vm is sometimes slower than a restore to an agent and based on the feedback from Jordan there are a lot of options to restore files.
try it on your environment to get a feeling for it!
Hope that helps you a little bit
Cheers Philipp
Same over here. We have a vm with million of files. Individual restore of files was impossible (using the VM backup). With a copy & transfer of the files it did work.
- Bit
- 3 replies
- January 26, 2021
Hello Christine, As other community members comment, there are many options for restoring individual files to a virtual machine. But if the restoration is of many files or of a very large volume of data, one option would be to restore the entire disk at the VMDK level, attach the disk to the original machine and copy / paste the files at the operating system level, from the new disk to the required path. If the client machine is Windows, this option is easier to do.
- Vaulter
- 15 replies
- January 26, 2021
if you know how many files\folders you want to restore then you have different option.
- if very few files\folders then agentless restore is good option.
- if you have large file\folders then agent based restore is good option. you just need to have commvault tools installed on the destination VM (File system core package).
- if you very very large files\folders restore then you can always do VMDK file level restore or attach disk to VM functionality.
let me know if you have any further questions\concerns.
- Vaulter
- 291 replies
- September 30, 2021
A file level restore from a Virtual Server backup will restore from block to file level. Since the backup does not backup the file but the blocks they are included in, the restore brings the block back and then pull the files from the blocks. If the file is spread out across 10 blocks., the restore has to first grab each one of those blocks out of the backed up chunks. It then needs to restore each block into a holding location and once it has all the blocks it can reconstruct the file and then place it to the restore location.
1) Perform a live browse of the data as this will use less space on the proxy building the data, but will still have performance issues for large restores.
2) Restore the VMDK the out place and attach to a VM. Copy the files you need then discard the disk.
3) Choose less files to restore at the same time.
Even if you were looking to restore just 1 file, it maybe spread across 10 blocks. The restore has to first grab each one of those blocks out of the backed up chunks and then restore each block into a holding location. Once it has all the blocks it can reconstruct the file and then place it to the restore location.
There are different options for these file level restores as listed here: http://documentation.commvault.com/commvault/v11/article?p=products/vs_vmware/c_vmw_restore_guest_files.htm
A 'guest agent' restore uses a Windows File System iDA installed on the client to run the restore. This is the most reliable and robust option for the restore of the data.
https://documentation.commvault.com/commvault/v11_sp20/article?p=36492.htm
Note: For the fastest recovery time and the least space required for extent caching, use Live File Recovery with a restore-only file system agent in the guest.
You can use agentless file recovery when the total restore size is less than 10 GB and you are restoring fewer than 10,000 files.
To restore virtual machine files and folders when the total restore size is larger than 10 GB or has more than 10,000 files, use a restore-only file system agent installed in the destination client or virtual machine.
An agentless restore has performance issues when restoring files at 10GB and\or 10k files. There are also additional caveats such as inability to restore ACLs.
https://documentation.commvault.com/commvault/v11_sp20/article?p=36497.htm
- Bit
- 6 replies
- September 30, 2021
A 'guest agent' restore uses a Windows File System iDA installed on the client to run the restore. This is the most reliable and robust option for the restore of the data.
https://documentation.commvault.com/commvault/v11_sp20/article?p=36492.htm
Note: For the fastest recovery time and the least space required for extent caching, use Live File Recovery with a restore-only file system agent in the guest.
You can use agentless file recovery when the total restore size is less than 10 GB and you are restoring fewer than 10,000 files.
To restore virtual machine files and folders when the total restore size is larger than 10 GB or has more than 10,000 files, use a restore-only file system agent installed in the destination client or virtual machine.
An agentless restore has performance issues when restoring files at 10GB and\or 10k files. There are also additional caveats such as inability to restore ACLs.
https://documentation.commvault.com/commvault/v11_sp20/article?p=36497.htm
This looks like what I will need to do for certain servers where I know restores of large files are likely to happen. Thank you so much for the advice.
- Byte
- 204 replies
- April 29, 2022
Hello!
If you need to restore some files from a File Server VM (~3 TB capacity), what is the best way to go?
From Command Center → Virtualization and then “Guest files” restore, I noticed that sometimes have a delay while browsing the contents (Browsing contents may take some time. Please wait...).

Is this normal or there is another faster way to browse these data and restore?
Thank you in advance!
- Bit
- 6 replies
- April 29, 2022
It seems to be a “pay me now or pay me later, but you’re going to pay” type of situation.
- Vaulter
- 291 replies
- April 29, 2022
A file level restore from a Virtual Server backup will restore from block to file level. Since the backup does not backup the file but the blocks they are included in, the restore brings the block back and then pull the files from the blocks. If the file is spread out across 10 blocks., the restore has to first grab each one of those blocks out of the backed-up chunks. It then needs to restore each block into a holding location and once it has all the blocks it can reconstruct the file and then place it to the restore location.
1) Perform a live browse of the data as this will use less space on the proxy building the data but will still have performance issues for large restores.
2) Restore the VMDK the out place and attach to a VM. Copy the files you need then discard the disk.
3) Choose less files to restore at the same time.
Even if you were looking to restore just 1 file, it may be spread across 10 blocks. The restore has to first grab each one of those blocks out of the backed-up chunks and then restore each block into a holding location. Once it has all the blocks it can reconstruct the file and then place it to the restore location.
There are different options for these file level restores as listed here: http://documentation.commvault.com/commvault/v11/article?p=products/vs_vmware/c_vmw_restore_guest_files.htm
A 'guest agent' restore uses a Windows File System iDA installed on the client to run the restore. This is the most reliable and robust option for the restore of the data. https://documentation.commvault.com/commvault/v11_sp20/article?p=36492.htm
Note: For the fastest recovery time and the least space required for extent caching, use Live File Recovery with a restore-only file system agent in the guest.
You can use agentless file recovery when the total restore size is less than 10 GB and you are restoring fewer than 10,000 files.
To restore virtual machine files and folders when the total restore size is larger than 10 GB or has more than 10,000 files, use a restore-only file system agent installed in the destination client or virtual machine.
An agentless restore has performance issues when restoring files at 10GB and\or 10k files. There are also additional caveats such as inability to restore ACLs. https://documentation.commvault.com/commvault/v11_sp20/article?p=36497.htm
- Byte
- 204 replies
- April 29, 2022
It seems to be a “pay me now or pay me later, but you’re going to pay” type of situation.
Hello Ron and thanks for your reply!
Where is this option about indexing (for file level restore)?
In case of this File Server maybe is useful !
- Byte
- 386 replies
- April 29, 2022
Hi
It’s in the properties of your VM subclient that you would set you want indexing to be performed, post backup :
Backup options tab, and at the bottom, checkbox to Collect file details
https://documentation.commvault.com/11.25/expert/62285_subclient_properties_backup_options.html
- Byte
- 426 replies
- April 29, 2022
I think in practice this is a really hard question to answer, due to practical constraints.
I will say that they best solution I have seen personally is a customer that provisioned a large restore vm in each datacenter to correspond to their physical location. This client was running the Filesystem agent and acting as a media agent. This made things like transport type irrelevant.
You could restore entire vmdks from san ndb etc with the same ease. Things like networking constraints are already address by virtue of being part of the cluster that was being backed up.
if this is an option for you, it can significantly reduce the headaches associated with restores.
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