The STOP button never works

[peterr]

This has been a problem for many years. When a session is running, the STOP button does not stop the process. Even waiting for a minute or two, the session is still running. I have always had to go into the System Monitor (KSysGuard) and end the process from there.

[Aaron]

Hello,

BC4's Stop button sends an abort command, and then must wait for a response from the system that the abort was received. This is often instantaneous when dealing with local locations, but network locations might take awhile to respond. Aborting early can potentially lead to corruption since the destination/system might still be working, despite the abort being sent, so BC4 waits until it responds or times out. For Windows Network Locations, this can be a minute or two if the network location is unresponsive. If it's not in a bad state, then it, too, could respond quickly.

[peterr]

BC4's Stop button sends an abort command, and then must wait for a response from the system that the abort was received. This is often instantaneous when dealing with local locations, but network locations might take awhile to respond.

This is local, so I wonder why the 'abort' from BC4 doesn't work for me, yet the 'abort' from the system monitor is instantaneous. You mentioned possible corruption, yes I was backing up and needed it to abort, BC4 wasn't making it happen, so I aborted via the system monitor. Then I couldn't use the external backup for a while, a bit of powering on and off. I do like the synchronise feature, saves so much time.

Although this laptop is quite powerful, there are some resource problems sometimes. There is a task called 'baloo' and it eats over 25% of the CPU, so if baloo is running, it MAY have stopped the abort being initiated by BC4 ?? Just a thought, and I do intend to remove 'baloo' completely one day.

[Aaron]

Quick search: looks like Baloo is the file searching and indexing process for KDE. Interacting with the files might be triggering their indexing.

If after killing the process the external device remains unresponsive, that sounds like it would have ignored our abort command as well and it is stuck in a bad state. This could be caused by a variety of things, but my first hunch is bad drivers or firmware on the external device. Are there any updates available for it? Also, if you perform the transfer using another program, like your regular File explorer, does the drive similarly behave badly?

[Aaron]

One other idea: perhaps the indexing task is too intensive for the drive while the copy is on-going. If you can disable indexing as a task/option, you may not need to remove/uninstall baloo, but tell it not to index the external device (or fully disable indexing, as a test, then customize the behavior later).

[peterr]

Thanks for your replies Aaron, much appreciated. Yesterday I was using Claws email and it was stuck on trying to get emails. I couldn't close it, it wouldn't stop, so I will research/investigate this a bit more, as it could be hardware or Ubuntu related ??

[Aaron]

Hardware or OS are always a potential factor, but email could also be indexing (if indexing is scanning into your email). Something about that could be stressing your machine, or is interacting poorly for some reason.

[peterr]

Thanks Aaron, now about 7 weeks later, I have finally got a fresh install of Kubuntu 19.10 . That said, I feel it is more this laptop (Dell), as recently was running a fairly intensive compare with BC4 on a very old HP laptop. I tried the STOP button and it worked immediately.

The Dell is quad core and about 4Gb ram and lots of swap and file space, yet it seems to have problems multitasking. It may need some research on Dell forums. Put simply, there is some sort of problem with it recognising interupts ??

[Aaron]

Is there very old laptop running the same version of the OS? An older version might not perform the same indexing.

Or, if it is a newer OS version and very old hardware, the OS might smartly disable the indexing as too intensive a task for that hardware combination.

[peterr]

Is there very old laptop running the same version of the OS? An older version might not perform the same indexing.

Yes, the old HP laptop is running Kubuntu 19.10, the same as this one.

Or, if it is a newer OS version and very old hardware, the OS might smartly disable the indexing as too intensive a task for that hardware combination.

Could be, I don't know what rules are made to compensate for old hardware. Today I was running a binary compare, about 91,000 files, and for some reason the external drive failed. So BC4 had no visibility of it, the HDD. So I used the 'stop' button, ..waited, tried again, ..nope, so had to terminate the process from the activity mananger.

Of course that was a different scenario, slightly, but for some reason that interupt is not being recognised. I was hoping the new OS version, Kubuntu 19.10 may have fixed it, but will now endeavour to chase up on the Dell side of things. If nothing there, then contact Ubuntu/Kubuntu teams to try and find out why.

[Aaron]

Hello,

If any network components are in play, the abort button can take a couple minutes to return a network time out. I'd let the stop button sit at least 5 minutes to make sure it is a difference between "a very long abort" vs. "won't abort". Was the laptop also comparing only two local folders on it's own internal harddrive? Did you notice any processes in the background taking up a lot of CPU?

[peterr]

If any network components are in play, the abort button can take a couple minutes to return a network time out.

There were no network operations at all. I made sure that Firefox had been exited. Plus, even if a browser was going, the CPU demand from that is extremely low.

I'd let the stop button sit at least 5 minutes to make sure it is a difference between "a very long abort" vs. "won't abort".

That's a very long time, but next time it happens, I'll wait 5 minutes.

Was the laptop also comparing only two local folders on it's own internal harddrive? Did you notice any processes in the background taking up a lot of CPU?

Usually that is the case - 2 local folders on the same HDD, but also the scenario of comparing a local to an external drive. I had 'top' running and also used the System Monitor to check CPU. Noticed that the System Monitor will report BC4 as using 10 % CPU, which is fine. Yet 'top' reports about 40 % . Then I realised 'top' is looking at the quad processor side of things, so it's value will be true. Usually using 'top' and the CPU for BC4 was avaerage 40 to 45 % and all other processes combined at 10 % maximum, so that still leaves a lot of CPU. On that note I must say that BC4 being used in an earlier release actually used a lot more CPU. The System Monitor would report 25% CPU for BC4, so that is really 100%. So, just saying that now using Kubuntu 19.10 and the latest BC4, the CPU usage is less than half what it was before. Which I'm pleased about. Yes it will take longer but at least other apps get some CPU.

[peterr]

I bought a new external hard drive, just to rule out hardware issues. The old external was failing anyway. The same problem happened. I did wait, some waiting was 1 minutes, another lot of waiting was 10 minutes. Also, Beyond Compare is taking much longer to copy filesets that the usual "cp" command. I have read any GUI will have an overhead though.

Am now looking at a command level tool called "restic", as sometimes Beyond Compare just hangs. It can't be the new external drive. Also, can BC4 run at command level, to test the 'sync' without the GUI ?

[Aaron]

Hello,

BC4 can run in a scripting mode from the command line, but this wouldn't remove any overhead.

What kind of performance difference are you seeing between BC4 and the cp command line? For any trials, I suggest multiple tests, alternating, to reduce caching as a factor. What kind of performance do you see if you use the graphical Explorer's copy/paste (instead of CP)?

Is baloo still running and taking a lot of resources? Or any other tasks? It sounds like that has disappeared given your recent explanation, but was present during your initial tests.

[Pete]

Another thought is to back up your BC settings, delete them from their normal location, then see if BC still has the same problem.

Stay safe everyone!