Adding more persistent disk images

[proctor]

i also have been working on getting KNOPPIX-DATA onto a dvd. i have tested garaden's solution above and can verify that it works properly once all the "dot-wh-dot" (.wh.*) files have been removed from the tarred KNOPPIX-DATA directory.

i also created a hacked version of the knoppix initialization script in the initramfs file minirt.gz which i will document a bit further at my original post http://www.knoppix.net/forum/threads...t-image-on-dvd

sincerely,
proctor

[kl522]

i also have been working on getting KNOPPIX-DATA onto a dvd. i have tested garaden's solution above and can verify that it works properly once all the "dot-wh-dot" (.wh.*) files have been removed from the tarred KNOPPIX-DATA directory.

Oh no, I wonder how people come to this conclusion about those dot-wh-dot files. In my view, if you want to copy a consistent copy of "file sets" ( ie collection of files ), you should rather copy the /UNIONFS counterpart, and not copy /KNOPPIX-DATA and omitting the dot-wh-dot.

A package is basically a set of files. Very often when you update a package (using synaptics for example), that might result in removing some older files on the read-only file system which does not have it's counterpart in the updated package. To mark that these read-only files as deleted, thereby there will be dot-wh-dot files created on the read-write file system.

The mechanism maybe too complicated to be explained here. But all in all, if you copy files on the read-write file system ( and omitting the dot-wh-dot files ), you will likely end up with having inconsistent packages.

[proctor]

by "copy the /UNIONFS counterpart" do you mean the entire system as opposed to "only the changes?" on my test system /UNIONFS consists of around 2GB data, whereas /KNOPPIX-DATA is only 140MB....

is there a better way to do what i am trying to do (use the persistent overlay image knoppix-data.img on a read-only media)?

sincerely,
proctor

[kl522]

by "copy the /UNIONFS counterpart" do you mean the entire system as opposed to "only the changes?" on my test system /UNIONFS consists of around 2GB data, whereas /KNOPPIX-DATA is only 140MB....

is there a better way to do what i am trying to do (use the persistent overlay image knoppix-data.img on a read-only media)?

sincerely,
proctor

Sorry it wasn't clear to me what you are trying to accomplish. But I am only saying that if you copy /KNOPPIX-DATA but omitting the dot-wh-dot files, you will have inconsistent packages.

[proctor]

well this is very valuable information to have!

what happens when the dot-wh-dot files are left intact is that when the init system tries to mount the tarred structure into the existing overlay, the dot-wh-dot files conflict/interfere with their already existing counterparts in the UNIONFS system.

do you know of a workaround for this issue?

proctor

[proctor]

hi,

after looking in more detail at aufs it seems to me that using the tarred /KNOPPIX-DATA (really a tarred mounted /KNOPPIX/knoppix-data.img) with removed dot-wh-dot files should not disrupt an aufs file system because the tarred system is not overlaid into the UNION and so therefore not merged in the same fashion that aufs uses: they are simply copied into the UNION, into the aufs.

it seems to me that this is actually the preferred method, and not my patch (at http://www.knoppix.net/forum/threads...t-image-on-dvd).

would anyone disagree with this?

proctor

[kl522]

hi,

after looking in more detail at aufs it seems to me that using the tarred /KNOPPIX-DATA (really a tarred mounted /KNOPPIX/knoppix-data.img) with removed dot-wh-dot files should not disrupt an aufs file system because the tarred system is not overlaid into the UNION and so therefore not merged in the same fashion that aufs uses: they are simply copied into the UNION, into the aufs.

it seems to me that this is actually the preferred method, and not my patch (at http://www.knoppix.net/forum/threads...t-image-on-dvd).

would anyone disagree with this?

proctor

It will not disrupt the operation of aufs, but you will have inconsistant packages, your file system will have additional files and directories which should not exist, ie files and directories which should have been removed by package updates will re-appear in the "tar copied" file system. That's what I believe should be the behaviour of 'aufs'. Your views may differ.