Add support of bcache in installer

Asked by Alexandre Bailon on 2014-04-06


I recentlly bougth a Dell laptop. It's working fine expect optimus and the hard drive horribly slow (a 5400 rpm hard drive).
For the last one, a solution exists: using my little SSD as cache. After a lot of difficulties, I managed to install bcache and use it to speed up my computer.

Because it was difficult for me to install bcache, and I'm pretty sure it will be for new user. For this reason, I'm thinking adding support of bcache in installer should help some people to speed up their hard drive with a SDD.

I would like modify ubiquity and d-i myself but I'm a bit lost with ubiquity/d-i architecture.
For me, the changes to be made are:
1 - update ubiquity UI:
   * add an option to enable bcache if the computer has a SSD and a HD
2 - update partman:
   * add a new partition scheme: 2 partitions on HD (boot and root) and one partition on SSD (cache)
   * create bcache device: this device will be used to install ubuntu

I already made few modification in ubiquity but I'm facing difficulty with partman.
I don't understand how ubiquity start and communicate with partman.

Can you give me some hint and advice to made this modification ?

Best regards

Question information

English Edit question
Ubuntu ubiquity Edit question
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Solved by:
Alexandre Bailon
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I suggest you report a bug.

I assume you are using Trusty. If not then try it.

I'm using Trusty. Why do you want I report a bug? I think there is a misunderstanding.

This is the first time I want to contribute to free software.
Actually there is only two options for computer with SSD and HD: installing the root partition on SSD and use HD for home partition or install the whole system on HD.
bcache offer a third option: install the whole system on "cached HD". This option can improve HD performance with small (and not expensive) SSD.
 I think installing bcache (not installation itself but his configuration) is not easy. Installing bcache and configuring it during the installation process will probably help some people.

Even if this not my favorite distribution (I rather like Gentoo), I really want to contribute to Ubuntu.
But because this is my first time, I will need a little help to start.

I will continue to work on the integration of bcache in ubiquity. I'm asking help to community to integrate make this work quickly and properly (more than I can do it alone).

Best regards

This place doesn't seems to be the best to ask technical question.

Thank for you help.