Re: [gentoo-catalyst] LiveCD UNIONFS overlay

[Georg Lippold]

I found out how to reenable unionfs, so don't bother with extracting the 
initrd. It seems to require you "special" option ;)

Greetings,

Georg

Georg Lippold wrote:
> Okay, I know it's very low on your priority list, but I figured out
> something new ;)
>
> How about scanning for the partition that shall be used for the initrd?
> It could be done with unionfs=scan and that wouldn't break compatibility
> for genkernel. I studied the UnionFS's scripts a bit longer and found
> that the file livecd.unionfs must exist on the partition that shall be
> used as rw-device for unionfs. Now it's easy to scan for it, just
> include the following function to
> /usr/share/genkernel/generic/initrd.scripts:
>
> find_unionfs(){
>         local FS
>         goodmsg "Scanning for filesystem with file /livecd.unionfs"
>         mkdir -p /union
>         FS=`blkid -c /dev/null | cut -d: -f1`
>         # find filesystem on blockdevice containing file livecd.unionfs
>         for i in ${FS}
>         do
>                 mount -t auto ${i} /union
>                 if [ -f /union/livecd.uinonfs ]
>                 then
>                         goodmsg "Found filesystem $i"
>                         UNIONFS=${i}
>             umount /union
>                         break
>                 else
>                         umount /union
>                 fi
>         done
>         rmdir /union
> }
>
> then the function setup_unionfs() just needs a little patch at the
> beginning:
>
> setup_unionfs(){
>         if [ "${UNIONFS}" = "scan" ]
>         then
>                 find_unionfs
>         fi
>
> You say it's known to be broken, what else needs to be fixed besides bug
> 99682 (and that is already resolved, as it seems)? I currently have the
> strange feeling, that unionctl is not copied to the initrd of the
> livecd, as it was not found when I booted from a CD made with 'genkernel
> --unionfs'. I tried to extract the file isolinux/gentoo.igz from the
> cdrom to check, but I didn't get all of it's contents, as it seems.
> 'gunzip -c gentoo.igz | cpio -i' has only this content:
>
> ./dev
> ./dev/console
> ./dev/null
> ./dev/tty1
> ./bin
> ./etc
> ./etc/fstab
> ./usr
> ./usr/bin
> ./usr/sbin
> ./proc
> ./temp
> ./sys
> ./var
> ./var/lock
> ./var/lock/dmraid
> ./sbin
>
> But the file has extracted ~17 MB... Mounting it with -o loop didn't
> succeed either, but maybe I'm not having the right FS in my kernel. Can
> you help me on this?
>
> For me this feature is very important, and I would be willing to
> maintain the unionfs of the LiveCD, if it helps you having more time.
>
> Greetings,
>
> Georg
>
> Chris Gianelloni wrote:
>
>> On Thu, 2005-09-08 at 21:05 +0200, Georg Lippold wrote:
>>
>>> If in /usr/share/genkernel/generic/initrd.scripts the function
>>> parse_opt is changed with the corresponding | as delimiter, then one
>>> wouldn't have to change anything else. It would look like this:
>>>
>>> parse_opt() {
>>>         case "$1" in
>>>                 *\|*)
>>>                         local key_name="`echo "$1" | cut -f1 -d\|`"
>>>                         local key_len=`strlen key_name`
>>>                         local value_start=$((key_len+2))
>>>                         echo "$1" | cut -c ${value_start}-
>>>                 ;;
>>>         esac
>>> }
>>>
>>>
>>> What is your opinion on this?
>>
>>
>>
>> We don't support UnionFS in any way and don't have plans on doing so for
>> some time.  We also do not want to break compatibility in genkernel
>> mid-release, as this caused us quite enough headaches between 2005.0 and
>> 2005.1's releases.
>>
>> To put it simply, the UnionFS support in genkernel is known to be broken
>> and not working well, which is why we have removed the --unionfs option
>> from genkernel.  It is so low on our priority list, that we're
>> definitely saying that we'll get to it "when we have time" and I can
>> tell you that I, personally, won't have time for months.
>>
>> Remember that genkernel and catalyst *are* two separate projects, and
>> genkernel must maintain usability.  We can't use a pipe to delimit
>> things, as that could be interpreted by the shell.
>>
>> Currently, all of our limited attention is focused on resolving bugs,
>> and working towards releasing catalyst 2.0 to the world.  I'd almost
>> expect a feature freeze on genkernel for some time, as we work to
>> stabilize the codebase.
>>
-- 
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