SIRIS, ALTO, and NAS: Error "Invalid Root File System" error



This article covers how to resolve an Invalid Root File system error that can appear when pairing an agent through the Agentless option. 


  • Datto SIRIS


Ensure that the available space is rounded to the nearest GB

Check that the volume’s virtual disk size is set to a whole number. Any storage set to a fraction of a GB throws a fractional size error, which can result in the Invalid Root File System message. 

Figure 1: Datastore

If the Virtual Disk Size is listed in TB, you can use the dropdown to view the value in GB, but do not press OK or APPLY.

If the volume is set to a fraction, round the space up to the next GB. In the image above, you'd change  the storage to 36 GB.

Address any "Disk needs consolidation" messages as necessary

If you see a "Disk needs consolidation" message, address it by removing excess snapshots.

Right-click the VM in the left pane of vSphere and select Snapshot → Snapshot Manager.

Figure 2: Snapshot Manager

Remove any hung Datto snapshots or any virtualizations that you no longer need. Highlight the snapshot to remove it, and then click Delete. You must perform this step yourself - Datto Technical Support cannot perform this step for you.

Figure 3: Delete

Once finished, run the consolidation process by right-clicking the VM again and selecting Snapshot → Consolidate.

Access system and application logs

If you still see the Invalid Root File error, access the system and application logs on the guest by running a  chkdsk /r and sfc scannow operation on the production machine. The log output of these operations will indicate if the machine has any filesystem corruption.

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