[Ubuntu-be] CopyKitten Benchmarks

[Wouter Vandenneucker]

small update:
I fixed the 1-drive-at-once-bug. Turned out I misplaced my "&".

Anyhow, we're now successfully writing 700MB to 3 drives in under 2
minutes..

Grts


Wouter

2012/9/28 Wouter Vandenneucker <woutervddn op gmail.com>

> Hi all
>
> So I'm messing around a bit with CopyKitten. Turns out: there are some
> glitches in the code..
> For some reason today the usb drives where written 1 by 1. I'll be fixing
> that later today on the train.
>
> *Benchmarking*
> *
> *
> This did allow me to do some benchmarking automated (I could get 3 sticks
> to write and log the time without having to sit behind my computer).
> Writing an ISO from one USB drive to the others takes an aweful amount of
> time because it goes through the total 4GBs of memory even when only 700MB
> is written.
> Using an ISO file goes a lot faster.
>
> *Unallocated memory*
> *
> *
> When I tried to use the normal Ubuntu 12.04 ISO it resulted in a bootable
> 700MB partition and 3.3GB of unallocated memory.
> I'm going to experiment with 2 partitions on the USB drive, because I
> believe that allocating that memory is faster than writing "empty space" to
> the drive using ddrescue.
>
> I let the program write 3 USB drives the times needed to do that are
> roughly: 5 minutes, 2.5 minutes, 3 minutes. Way less than writing from USB
> to USB.
> However, you should note that those times are for 700MB ubuntu bootable
> and 3.3GB unallocated.
>
> Claudio, how do you solve this "unallocated memory"?
>
> *Blocksize*
> *
> *
> One of the other "optimizations" I made is changing the default block-size
> at which ddrescue writes to the usb drives. It turns out that 5MB goes
> well, and depending on the harddrive you could crank that up. I'll be
> testing some drives here but I am wondering how fast we could get using an
> SSD with optimized blocksize.
>
> (if we can write 4GB in less than 3 minutes we don't need to worry about
> allocating memory)
>
> *Future steps*
> *
> *
>
>    - For now I'm going to change to code to write all drives at once
>    - Optimze the blocksize even further
>    - Get rid of a bug that you encounter when you use an ISO instead of a
>    master drive
>
>
> Grts
>
>
> Wouter
>
------------- volgend deel ------------
Een HTML-bijlage is gescrubt...
URL: <https://lists.ubuntu.com/archives/ubuntu-be/attachments/20120928/afcf66c6/attachment.html>