Q-Hybrid troubleshooting



Q-Hybrid technology is used by Alike in a variety of situations, and can take a bit of tuning in some cases to work correctly. Please note that Alike's Hyper-V and Physical support both utilize Q-Hybrid for nearly all operations, so many of the following steps can be helpful for Hyper-v and Physical troubleshooting as well.

Q-Hybrid works by dynamically deploying agent binaries to the remote (Windows) system using a mixture of WMI and CIFS/SMB access to the target system. Both of these must be functioning properly for Q-Hybrid to work. The most common problems here are authentication errors (see Credential Profiles below), and routing/firewall issues.

Once the binaries are deployed to the target system, a vss snapshot is taken of the selected disks. Microsoft VSS troubleshooting is it's own topic, and there is a lot of help to be found on the web. We also have a KB with some useful tips if you are experiencing VSS problems.

After a vss snapshot has been taken successfully, Alike's backup agent will begin the data transfer process. This requires a socket connection back to the A2 on TCP 2811 (default) for all the new backup data. This step is very susceptible to security software on the Q-Hybrid target (Windows Defender, Sophos, and other anti-virus software), as well as network based security solutions that might intercept/inspect the traffic and cause an interruption.


Q-Hybrid requirements:

  • WMI/DCOM Access to the target system from the A2
  • Access to the target system's Admin windows share (admin$) (SMB 2.1 or higher required)
  • Functioning VSS within the guest being protected
  • A proper Credential Profile defined for authentication
  • A windows partition that is sector aligned on an MB boundary. (All OS's since 2003/XP have this by default)

Credential Profiles

At least 1 Credential Profile must be defined for any Q-Hybrid backup to work. A profile is a username/password that Alike uses to authenticate to remote systems with Q-Hybrid. One profile can be used for all systems in a single authentication domain, or you can add as many as you need for your security settings. You can define/edit your Credential Profiles in Alike's menu: Tools->Settings->Backup Settings. To assign a particular Credential Profile (other than the default) to a VM, you can do so on the VM's System Details panel, in the menu: Systems->System Explorer->(your vm)->Show System Details.


Access IP

By default, Alike will use the integration tools to detect a guest's IP address to connect with for Q-Hybrid operations. This is a common point of failure in Q-Hybrid jobs. The simplest thing to do is ensure that the integration tools are functioning properly, and reporting an IP address for the VM in the hypervisor's management console. However, if this does not work, or you want to specify a particular IP address for that system, you can assign an "access IP" for that VM in the Vm's System Details.


Common Q-Hybrid Errors

"Delayed cache write on remote filesystem"

This happens when the A2 writes a file to the remote system's admin$ share via SMB, but it does not show up to locally running command/binaries running on the remote system. This can be caused by an overloaded target system, group policy settings, but it most often due to anti-virus or other security software. Sometimes the remote system's event log will have some description of the problem.


"IRPStackSize is too small. Failed to run remote command"

This can be caused by UAC. Please see the KB article on this topic for more details.


"Failed to mount QSI via CIFS"

The A2 was unable to mount the target system's "admin$" share, which is generally either a networking or permissions issue. Please double check the credentials (in the credential profile you are using), and test access to the target system from another computer.


"QHB error (remote): Application ended prematurely."

This indicates the remotely running Q-Hybrid agent was unexpectedly terminated or crashed. In all known cases, this has been caused by security/anti-virus software running on the remote system. If this is the case, adding an exclusion to the "C\Windows\QSI\" folder should correct the problem.


"Status could not be determined for remote process"

This occurs when the remotely running process (Q-Hybrid agent) closes, but the results of the program can't be found. The most common cause of this is networking related (IP conflict, or some other intermittent) which causes the A2 to lose it's network connection to the remote/target system while a job is running. Checking the target computer's event log, or the A2's system log might help narrow down the cause.


"Remote file is in use (QSQHBAgent.exe). VM appears to be in another running job"

This error indicates that the Q-Hybrid agent (QSQHBAgent.exe) is still running on the target VM. This can be due to a failure in a previous job, or if you have another Alike installation in your environment protecting the same VM.

To fix this issue, you can kill the "QSQHBAgent.exe" process running on the target VM, and re-run the Alike job. This should allow Alike to cleanup and remove the stale agent binary, and deploy a new one.