[arch-releng] squashfs

[Christian Hesse]

Gerardo Exequiel Pozzi <vmlinuz386 at yahoo.com.ar> on Tue, 2012/10/02 15:51:
> On 10/02/2012 12:56 PM, Mr Green wrote:
> > This is more likely not the correct place to ask, but I am interested 
> > in finding out more about mksquashfs. Currently I notice that 
> > root-image.fs.sfs once mounted gives root-image.fs which then also has 
> > to mounted [looped]. Is there a way to only mount and copy once? The 
> > root-image. Have noticed that some other live isos only need to copy 
> > out image to new install.
> >
> > MrG
> >
> what you want to do?
> 
> This is done in this way because we need a writable block device plus 
> compression, this is done:
> 
> [rw-fs] (ext4 /) -> [dm-snapshot] -> {ro-fs-loop} (origin)  + 
> {rw-cow-loop} (COW)
> 
> {ro-fs-loop} -> [fs-image] -> [ro-sfs-loop] -> [sfs-image] -> [ro-fs] 
> (iso9660 / extfs / vfat)
> {rw-cow-loop} -> [cow-image] -> [rw-fs] (tmpfs/non-persistent | 
> extfs/persistent)

AFAIK there is a good reason why it is made this way: Others use squashfs
with any of the union / overlay filesystems (unionfs, aufs). But these are
maintained outside the kernel, making it difficult of the Arch developers to
release filesystem module packages (and thus linux packages) in time.
After all Arch is a rolling release system and we love to have latest
software. ;)
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