Overview
This article explains why certain virtualization and container applications on macOS can cause Druva inSync (Druva inSync) snapshot sizes to appear much larger than expected, how to confirm the issue, and how to resolve it by excluding the relevant folder paths from your backup set.
Symptoms
You may observe one or more of the following:
A sudden and significant increase in endpoint backup or snapshot size — for example, a device with approximately 200 GB of data shows multi-terabyte backups.
Backups take longer than expected or fail due to the volume of data being processed.
A file such as data.img appears extremely large in inSync backup selections or logs.
Cause
Why the snapshot looks inflated
Some virtualization and container applications — such as OrbStack — create sparse virtual disk image files (for example, data.img). Sparse files have two distinct sizes:
Apparent (logical) size — the maximum size the file could represent. Many tools display this value.
Size on disk (physical size) — the space actually allocated and stored on disk.
OrbStack's data.img is intentionally created as a large sparse file for dynamic storage management and is commonly shown as 8 TB in apparent size. OrbStack documents this as expected behavior and recommends excluding the folder if a third-party backup tool reports an issue.
For reference:
How inSync is affected
inSync may capture and report the apparent (logical) size for certain sparse files, which makes backup and snapshot sizes appear far larger than actual disk usage.
How to confirm the true file size on macOS
Option 1: Terminal
Run the following commands (replace the path with the actual location of data.img on your device):
ls -lh "<path-to-data.img>"
du -h "<path-to-data.img>"
ls -lh typically shows the apparent size (for example, 8.0T).
du -h shows the size on disk (actual usage).
Option 2: Finder
Right-click the file.
Select Get Info.
Compare the Size value against the Size on disk value.
Resolution
Exclude OrbStack data from backups
If you do not need to back up local containers, images, or virtual machine (VM) data from OrbStack using inSync, exclude the OrbStack data directory from your inSync backup set using profile exclusions.
OrbStack data locations to exclude
OrbStack commonly stores data under the following path:
~/Library/Group Containers/HUAQ24HBR6.dev.orbstack/data
Depending on your OrbStack version or configuration, the following path may also be present:
~/.orbstack/data
Exclude the folder that exists on your device. Many users exclude the .../data folder.
For OrbStack's own guidance, see the OrbStack FAQ.
How to add the exclusion in Druva inSync
Exclude via profile
Sign in to the inSync Management Console.
Go to Profiles and select the profile assigned to the affected macOS users.
Locate the Global Exclusions section (or the exclusions section for endpoint backup).
Add the OrbStack folder path or paths:
~/Library/Group Containers/HUAQ24HBR6.dev.orbstack/data~/.orbstack/data (if present on the device)
Save the profile and run a new backup.
📝 Note
After you add an exclusion, the reduced snapshot size will be reflected in subsequent backups. Older restore points will remain available in accordance with your retention policy. You can remove the affected restore points to reduce down the storage consumption.
I📝 Important Notes
Exclude only if acceptable. If OrbStack container or VM data is critical to your organisation, excluding it means inSync will not protect that content.
Broader impact. This behaviour is not exclusive to OrbStack. Other applications may create sparse disk images that also appear very large in backup tools.
If you need the data protected. Consider backing up the source project directories — such as code files and configuration files — instead of the VM or container disk image itself.