Backup ALL local shares to USB drive

I would really like to so an rsync backup to my local USB drive without having to specify a remote server.

I have tried using the server name, "localhost" but even if the remote server is "locahost" the network connection causes rsync to perform block-level file updates. While block-level, file updates are efficient for network connections, they are not very efficient for copying to local disks, especially when some very large, 10 to 30 GB, files are involved. It takes far longer to compute the checksums than to simply copy the entire file if it has changed size or modify time.

It's not clear to me how the backups work with USB device chosen as the destination. It does not appear to be an rsync backup. It's missing some options such as being able to specify exclusions and to delete files from the destination that no longer exist on the source.

Is there any support for truly local rsync, aside from running rsync from the command line?

We've had problems from the first release of the OS6 units, We've 516, 102 & 104 units all with backup to USB issues. (and yes we've tried every version of Firmware upto 6.1.6)
We've tried USB3 & USB2 & eSata, all seem to fail at some point with a backup error of 'Backup Status: Fail: destination is read-only'
The worst problem that Netgear have been aware of is try to use AFP, every time we mount or dismount the external drive the share drops off the network (Netgear have been aware since October last year and still no fix)
It's such a shame they can't fix a simple thing like performing a backup, which everyone must need to do if they don't want to loose all their data!

Just an update, I did not have any issues following the instructions above. I DID however start having issues with the external hard drive I was using. So if you're having issues with this setup, make sure to consider if your external drive is causing the instability.

I'm considering investing in a really nice USB 3.0 SATA dock and just buying a hard drive for it. That way I can easily swap out either component if I start having issues.

I just filled a 4TB USB3 drive with what was supposed to be a backup of a 1.3TB volume, and it wasn't done. Then I discovered this thread.

This was on an OS6.1.7 RND314 w/four, 3T disks.

I agree that it's broken that backing up the entire volume /data to an external USB drive produces almost an order of magnitude more data than what appears on the volume itself. It certainly doesn't work as I was lead to expect by the documentation. Who do we complain to at NetGear about this?

I am now about to try Pixel8's suggestion.

Another option is to delete all the snapshots prior to the backup.

So Pixel8's suggestion worked for me. For the amount of data copied, it proceeded at about 20% of the speed of the direct copy to the USB3 drive.

But I still wound up with a data expansion. The system overview page says that my main volume contains 1.29TB of 7.85TB. But my backup drive, with one full, initial backup on it, has 2.58TB of 3.58TB.

I assume the rest came from the snapshots. So before my next backup run I'll follow StephenB's suggestion and delete most of those and see what happens.

When I select to backup 'volume' to external drive, after several hours of backing up and 1TB space used on external drive, no files were showing on the external drive. I have snapshots turned on. I thought i'd at least see some folders and files.

I cancelled the job as it was taking more space than what was actually on the NAS volume.

I suspect it was copying the snapshots (which are in a hidden folder). Normally they are linked into multiple folders, but that isn't preserved when they are copied.

I suggest backing up each share as a good alternative. Another option (more complex to set up) is to use rsync, but exclude the snapshot directories.

Thanks StephenB. I'm backing up share by share now. Once complete I'll setup rsync.

Also set the snapshots so they aren't user accessible.