Hi Folks,

At the recent wlug meeting Michael McDonald commented on the slow speed when loading the latest (12.10) "live" version of Ubuntu (Unity) from a USB drive. Michael thought the slowness may have been due to having selected the option to create a "persistence file" on the USB drive.

I have done some testing and my results tend to confirm Michael is correct... as follows...


Using a 12.04 system I used its "Startup Disk Creator" to build the "ubuntu-12.10-desktop-amd64.iso" image onto a 4GB USB stick.

Startup Disk Creator offers two USB disk choices, "When starting up from this disk, documents and settings will be:"

1. "Stored in reserved extra space". (You then select "How much", to which I took the default of 1GB). This is the default option and it creates a "persistence file" which is formatted as an ext2 partition.

or...

2. "Discarded on shutdown, unless you save them elsewhere".

Having created a USB disk using the first option with the persistence file, I booted the USB drive on an Intel DUO core, 2.5GHz laptop with 4GB RAM.

It took 4 min 30 seconds to complete the initial phase and get to the "Try Ubuntu" or "Install Ubuntu" choices. On selecting "Try Ubuntu" it took 3 min 30 secs to finish booting.

When I created the USB disk using the second option of "Discarded on shutdown" (without a persistence file), the initial booting phase took 45 seconds, and the "Try Ubuntu" phase took 15 seconds.

In summary, the first way took a total of 8 minutes, while the second way took 1 minute. On a slower computer, then the first way could be so slow that you may get the impression that the installation has had a problem and hung.


Conclusion:

As the ubuntu 12.10 iso images no longer fit on a CD then there is more chance you'll be using Startup Disk Creator to put the .iso image onto a bootable USB drive. If you are doing this for the reason of doing fresh installations to HDD's, then, for improved install performance, create the USB drive using the option: "Discarded on Shutdown" (i.e. Not having a persistence file.)


cheers, Ian.