hyper-v backup

[peterp666]

Can I backup live vms?
VHD files specifically ?

[superflexible]

Yes

[jack-tci]

We are evaluating syncovery for exactly this purpose - replicating hyper-v vhd files to a DR site.

We are using Partial File block diff to speed up the process. Would you mind sharing your experience, especially configuration settings for large vhd files (500+GB)?

[superflexible]

Yes some customers do this with success.

There aren't a whole lot of options, please see here:
http://www.syncovery.com/block-level-copying/

[jack-tci]

Yes, thank you, I had already read the block-level-copying page. That is what convinced me to try your software.

Since we are replicating an entire hyper-v vhd file, I have checked "Volume Shadowing" in the Access & Retries -> File Access tab. Furthermore, I have checked the "Database-Safe Copying: Enforce Exclusive Access" option.

I am hoping this will allow us to accomplish all of this:

1) Replicate the vm's entire vhd file without having to shutdown the vm.
2) Copy only the changed blocks of the vhd file.
3) Allow for safe replication of SQL Server databases onto the replicated vm, such that the replicated databases are usuable and up-to-date as of the beginning of the replication.
4) During the replication process, the SQL Server databases on the source vm are available to their web applications, but perhaps as read-only access from their web applications.

Can you comment on this?

Does this scenario seem correct to you, or I am failing to understand some aspect of the syncovery process?

Thanks in advance, I am excited about using your software!

[superflexible]

Yes it should work fine. The first copy will copy all blocks even if the destination files are already there, because the file is not in the database yet. To avoid this, you can use the Remote Service for generating checksums. This will also make it possible to recover from interrupted copying operations without re-copying the entire file.

[jack-tci]

1) On the remote destination server, can I generate checksums on vhd files that were previously transferred there by syncovery? If yes, how?

2) I installed remote service on destination server, and used syncovery to transfer a large vhd file with sftp.

Unfortunately, subsequent transfer attempts by the source server Syncovery cannot find or read the remote checksum. It gives this error: Error reading checksum file. Retries are unsuccessful. Can you give a detailed configuration for using remote service (config on both source and destination servers) for recovering from interrupted copying? These files are too large to recopy-in-full if there is an interruption.

Thanks!

[superflexible]

It's definitely possible. You need to use the Syncovery Remote Service Control Panel and specify the main profile folder on the Checksummer tab sheet, and then start the service or click Apply.

You should see that Syncovery uploads checksum request files and that the remote service processes them. These files are hidden by default, so you need to turn on hidden files in Windows Explorer in order to see them.

If problems remain, please send a log file from the main app which enables me to check some of the things.

[jack-tci]

After a bit of trial-and-error, this is working.

The "waiting for MD5" message on the source server times out too quickly. The Remote Service "creating checksums" often takes 15 minutes to 2 hours to complete because the Hyper-V vhd files are large (60 Gb to 550 Gb) and the source and destination servers are 700 miles (1100 km) apart.

Is it possible to increase the "waiting for MD5" timeout from 120 seconds to 7200 seconds (2 hours), or change the "waiting for MD5" timeout to default to Yes (continue waiting), or speed up the process some other way?

Overall I am quite happy with Syncovery; I am just trying to improve the process now.

Thanks.

[jack-tci]

How can I increase the "waiting for MD5" timeout from 120 seconds to 7200 seconds (2 hours)?

How can I change the "waiting for MD5" timeout to default to Yes (continue waiting)?