Copy large files will fail

[bentam]

Aaron,

I am going to have a trip for a couple of weeks. I'll get back to you after returning home and doing some tests.

Ben

[Aaron]

Hello,

Does it consistently fail every time with a specific file? Does it fail at the same spot or does it randomly fail after a certain period of time?

The drive letter points to a mapped network drive. Do you get better performance if you put in the full network path (\\computername\folder\)?

[bentam]

Hi Chris,

So far I find this problem only in VPN and VHD. We are using Cisco routers and firewalls. The VPN software is provided by Cisco.

Ben

[Chris]

Hi Ben,

Are the copy problems limited to only copies through the VPN?

Are you running a software VPN client on your computer? If so, what software are you using?

[bentam]

Hi Chris,

Please see my post to Michael on this thread.

Thanks,
Ben

[bentam]

Sorry Michael. My prior reply should attention to the Scooter Team rather than you.

[bentam]

Hi Michael,

This seems not a problem of VHD. I get similar problem when copying large files between 2 real hard disk on computers connected with VPN over the Internet (broadband). Please see the attached figure. The problem is reproducible.

Both copying via VPN or to VHD are slow. Will it be a timeout problem? I'd be grateful if you would look into it.

Thanks,
Ben

[bentam]

Thanks for your explanation. It is a dynamic VHD. However there is no problem copying files over 10MB using the Windows Explorer. BC3 will fail even if the file size is over 1.5MB. I am sorry that I will regard this as abnormal.

[Michael Bulgrien]

A virtual hard disk is a single file that simulates a physical hard drive. A fixed VHD is created to be the same size as the virtual hard disk. For example, a 30 GB fixed VHD will take up 30 GB of space on the server that is hosting the file.

A dynamically expanding VHD is only as big as the data it contains. The more you put into the VHD, the larger it grows until it reaches its defined size limit. A dynamic VHD will show up in the Windows Disk Management console as it's defined maximum size, not its current physical size. For example, a 30 GB dynamic VHD file may only be 10 GB on the server that is hosting it. In the disk management console, it will show up as having 20 GB of free space. But if the hosting server runs out of available disk space before the VHD file can dynamically expand to its defined maximum size, a process that would cause the VHD file to expand (i.e. copying a large file to the VHD) will fail.

[bentam]

I don't know the difference between fixed and dynamic. It is for development use and will be started only when needed.

[Chris]

Is the VHD fixed or dynamic?

[bentam]

Yes I can. Sorry about forgetting to mention it.

[Chris]

Ben,

Can you write files over 1.5 MB to shares on the same Windows 7 PC that aren't on Virtual HDs using Beyond Compare?

[bentam]

I have been using Windows Explorer for copying large files for about 1 month. No problem has been found in the copied files. They are still usable.

I guess the problem is that the target folder is in a Virtual HD running in Windows 7. I can't remember the Virtual HD was created in Windows Vista or XP. The same problem shows in another Virtual HD (also created in prior OS) with different contents.

I try using BC3 to copy a large file into the VPC. Correct file name and size are shown in the target folder while the file time changes to current time. The resulting file is unusable.

Ben

[Chris]

Can you copy the same files using Windows Explorer?