Sorry Bruno, I accidentally sent the 1st reply to your personal email.
On Sep 26, 2011, at 4:36 PM, Bruno Wolff III wrote:
On Mon, Sep 26, 2011 at 14:45:19 -0500,
Ed Sutton <ESutton@fescorp.com<mailto:ESutton@fescorp.com>> wrote:
I need to add persistence for application configuration files and /etc/sysconfig/network
configuration. I need to create a "write once or twice" partition made on CF
and I assume create symbolic links on the read-only partition to the "write once or
twice" partition. The remainder will be read-only for a CentOS 5.2 LiveCD for
embedded applications that boots and runs off a Compact Flash (CF). Can someone please
point me to an example of persisyence?
Not sure if UninFS is a viable direction but I found references to UnionFS but am still
Thanks in advance for any direction,
You could take a look at what the --overlay-size-mb option does for
livecd-iso-to-disk to make this work for liveusb devices.
I tried this hoping it would work yet It did not seem to persist anything. The problem
may be I am using a Compact Flash IDE adapter rather than USB.
If it did work it sounded like any event logging would fill this up fairly quickly unless
I can configure event logging to write the RAM overlay as it does now but other write-once
configuration such as /etc/sysconfig/network could use the overlay-size-mb.
Limited Lifetime of Persistent Overlay
One very important note about using the "primary" persistent overlay for system
changes is that due to the way it's currently implemented (as a LVM copy-on-write
snapshot), every single change to it (writes AND deletes) subtracts from its free space,
so it will eventually be "used up" and your USB stick will no longer boot.
Because of these limitations, it is advisable to use the system-level persistence
sparingly, for configuration changes and important security updates only. For a truly
persistent write-many (vs write-once) overlay, use the --home-size-mb option to create a
home directory filesystem image for personal files. Unlike the primary system overlay
image, the home.img can be re-used and loop mounted outside of the liveusb environment.