Douglas McClendon wrote:
Douglas McClendon wrote:
> Question: Does the current livecd installer inefficiently write lots
> of 0's to the destination drive that it doesn't need to?
>
> I think it might. The os.img on the F7 livecd is a 4G sparse file
> with about 2.3G of data. Anaconda's livecdcopy backend uses python's
> os.read/write. I would guess that that means that 4G of data is
> getting written, when theoretically only 2.3G needs to.
>
> The solution that comes to mind is this-
>
> in livecd-tools, create the os.img as a 7G (or 700G??) sparse file.
> Basically just way big. Then take care to make the ext3fs be the
> exact correct size for the data (i.e. 2.3G). Then, in the initramfs,
> just after mounting it (after snapshotting it), do a resize2fs to 7G
> (or 700G).
To clarify a bit- Clearly the resize2fs should probably happen during
boot (long after initramfs). No need to bloat the initramfs with
resize2fs.
Yeah, I really gotta stop posting when I'm sleep deprived. Clearly in initramfs
you have access to sysroot thus no bloat.
and...
Also, the mechanism that comes to mind for the ext3fs creation is
this-
Take the existing image built as is, but after final install, resize2fs
it to the smallest possible (nearly), then truncate the file, then do
the dd seek trick to re-sparsify it vastly larger.
Or perhaps just throw in an entire extra tarcopy of the system to a new
fs image file created the exact right size from the beginning. This is
more work, but will possibly save space on any files that got created
and deleted during the installation process.
clearly the resize2fs to minimal will take care of the created/deleted issue.
-dmc