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Resetting delta state on every backup

yuriy.marushchenko :

Sep 15, 2017

Hi!

I have a router with a connected USB HDD (ext3 file system) and trying to backup to it, but every time backup is started, it is being created from scratch (even if I cancel the partial backup and start it a new).

Typical log message:
https://i.imgur.com/Qv7K0YO.png

All files, even the small ones, are copied again and again with every backup start.
I read similar topics on this forum and set the following in the Bvckup 2 settings:

conf.mtime_gran                                    10000000
conf.ctime_match                                   1

I also made sure that clock on the router is correct.

What else can be done to make the backup work?

P.S: I also noticed this error in the log:
https://i.imgur.com/PvsUYpg.png

Alex Pankratov :

Sep 15, 2017


What is the router (vendor/model) ?

There's something fundamentally wrong with how it handles "modified" timestamps on files. In your first screenshot - see how the "Now" timestamp for the file matches the log entry's own timestamp?

This means that the router adjusts "last-modified" timestamp on a file as soon as a program opens it, but before any actual changes are made. This should not be happening.

If this was working OK previously and started happening just recently, I'd try and see if this might've coincided with a router firmware update. If it did, you may want to complain to the router people and roll back to an older version. This won't be the first case of a buggy firmware update, Synology pulled something like this a year ago and it took them a couple of months to resolve it.

All this said, it may be also be because of a misbehaving antivirus. Not likely, but these fine pieces of software engineering is a reliable source of all sorts of weird and sudden changes in file system behavior.

---

WRT how to work around this - it's not possible. "Modified" timestamps are _always_ compared and a file will be updated whenever they don't match. So the only solution is to correct the root cause.

---

Re: second screenshot - this comes from the router, no idea why, sorry.

Alex Pankratov :

Sep 15, 2017



Ah!

It's a MikroTik router. Another person reported an almost exact issue back in July 2016. He also reported the issue to them, so they were aware of it for at least a year. Might be a good idea to poke them and see where they are at with resolving it.

yuriy.marushchenko :

Sep 15, 2017

Yes, it's Mikrotik:
https://mikrotik.com/product/RB962UiGS-5HacT2HnT

The first disappointment was that it does not support NTFS on external drivers. And the second is this issue with backup :(

yuriy.marushchenko :

Sep 15, 2017

Can you please give me the link to the post in July 2016? I cannot find it via on-site search.

Alex Pankratov :

Sep 15, 2017



It was in an email exchange, sorry.

Router model was RB493G, firmware version 3.18. There were two issues - one was that "modified" timestamps were changing well after files were updated, and the second was that some folders were reported as 0-sized files when the storage was scanned.

yuriy.marushchenko :

Sep 15, 2017

I took another approach and going to buy a simple NAS from QNAP. Do you know of any issues with this brand?

Alex Pankratov :

Sep 16, 2017



QNAPs are generally OK. We have _lots_ of clients who use their devices.

There used to be an issue with QNAPs reserving some names for internal use (like "p2p") and throwing weird errors when trying to copy files with names from this list. But it was a while ago (~2 years?), might've been fixed since then.

yuriy.marushchenko :

Sep 25, 2017

I installed QNAP TS-228 NAS and configured Bvckup to back up files to it. It works like a charm! No more issues with HDDs connected to routers.

yuriy.marushchenko :

Sep 25, 2017

BTW, should I reset these settings to defaults?

conf.mtime_gran                                    10000000
conf.ctime_match                                   1

Alex Pankratov :

Sep 25, 2017



Yep, just delete these lines from the INI.
And congrats on the upgrade :)

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