I am backing up all of my photos and docs, so I have purchased 160GB of storage. Yes, it is a lot of photos...

I am finding that my system is running very slowly while the backups are taking place, and Ubuntu One is taking up a massive amount of my CPU time. System monitor is reporting it using 40-170% of the CPU time. I also can't easily view my 'Pictures' folder, i seems to hang for a long time figuring out which folders have/have not been backed up yet (I guess).

I am running Ubuntu 12.04 LTS with all latest patches. I have laptop with a Intel i5 processor with 8GB ram.



Before uploading to the server, Ubuntu One needs to take a checksum of each file, and that involves reading the file in its entirety. If you do it 160GB in one chunk, it will likely take a whole day to churn through it, and depending on the disc you have it on can make the system slow. This is inescapable, although there might be some ways to mitigate its impact in your work.

In general the Ubuntu kernel should be smart enough to find the sweet spot in the compromise between getting the work done and over with, and letting use your machine. If you need it to back off a bit, you can use nice and ionice to do that. For example, you could use ionice to set ubuntuone-syncdaemon to only hit the disc when nothing else needs it, and use give other processes some preference for CPU usage,

$ ionice -c 3 -p $( ps h -o pid -C ubuntuone-syncdaemon )
$ renice -n 10 -p $( ps h -o pid -C ubuntuone-syncdaemon )

keep in mind that this will make the process take a lot longer (but given that it'll start uploading as it goes, it might not be a problem). This should, as a side effect, lower the CPU usage as it will have less data to checksum in any given moment in time.

  • Very descriptive and apt answer, thanks. I don't mind the time it takes so much, it is more the overloaded CPU resources it consumes. How many files does it try and checksum in parallel? – Simon May 12 '12 at 15:43
  • Only one checksum is done at a time; the syncdaemon has a queue. However, once checksumed, it's quite likely that the file will be compressed before upload, and that would happen in parallel with the next checksum, so if you have more than one core it can easily use more than 100% of CPU. – Chipaca May 14 '12 at 16:49

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.