[Box Backup] Controlling rate in lazy mode

[Adrian Cox]

On Fri, 2004-10-08 at 12:25, Martin Ebourne wrote:
> I have to say I don't have the problems originally described and I'm
> running on Linux (FC2) using lazy mode. In fact I don't even notice that
> its running while using the machine.
> 
> I'm only backing up about 4-5GB of data at the moment - maybe Adrian's
> backing up large drives which change fairly often?

That's right - around 40GB of data, backing up over a LAN. The data
isn't changing very fast, though. The load seems to be caused purely by
directory access.

> Two things to look at on Linux would be niceing the process, and maybe
> altering the kernel swappiness control. This latter controls how keen
> the kernel is to swap apps out to make space for disk cache and file
> buffers. If you're scanning a lot of files once there's no point
> swapping apps out to cache them, and for a desktop machine it's rare you
> ever want to swap apps out for file caching. Personally all my
> interactivity complaints with Linux went when I tuned it from the
> default of 60 to 25, and it still makes good use of the swap partition.
> (Google for 'swappiness' for more info)

Good point - I'll try adjusting swappiness. That may do more than nice,
as the idle CPU load on the machine is less than 10% while boxbackup is
running.

- Adrian Cox
Humboldt Solutions Ltd.