Comment 69 for bug 1333140

I have done repeated installs of 14.04 LTS and 15.04 on an HP Stream 11 notebooks.

This issue generally does NOT occur, other than briefly during initial load of Ubuntu installer (and sometimes during early stages of install). This adds no more than 15% to the time it takes to install Ubuntu (with eMMC storage), and will usually take less than 30 minutes.

However, I realised recently that this was ONLY true for new machines, or those I had already installed Ubuntu on. Out of the box, I was interrupting initial startup (at screen backlight on) to go directly to (BIOS controls for) booting from USB device.

For machines that had were already running Windows 8.1 (or even just asking for region / user details), it will no longer cleanly install Ubuntu. I have had it take from 2 hours to 5-7 hours, or just stall (after about 40 minutes) with continuous errors. This appears to be spurious interrupts (which cause further errors) due to attempts to access the RPMB partition. I am NOT even convinced that the Ubuntu installer is causing these interrupts.

The other possible 'root cause' is that the problem machines (NEW or used) were older, the same model Notebook but with an earlier generation / step release of eMMC chips. I don't have a large enough pool to prove this, but someone may be able to shed light.