Re: Finding parameters of existing ext2fs partition

[Edgar Pettijohn <edgar%pettijohn-web.com@localhost>]

On 02/23/20 19:54, Thomas Mueller wrote:
> from Jason Mitchell:
>
>
> > Does dumpfs supply any useful info?
>
> amelia2# dumpfs /dev/dk19
> dumpfs: /dev/dk19: could not find superblock, skipped
>
>
> I didn't think dumpfs would work on non-ffs/ufs filesystems.
>
>
> Tom
My manual claims that -O 1 is the default at least for:

NetBSD laptop 9.0 NetBSD 9.0 (GENERIC) #0: Fri Feb 14 00:06:28 UTC 2020 
mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64

 -O filesystem-format
                 Select the filesystem-format.
                       0    `GOOD_OLD_REV'; this option is primarily 
used to
                            build root file systems that can be 
understood by
                            old or dumb firmwares for bootstrap.
                       1    `DYNAMIC_REV'; the default.  Various 
extended (and
                                            ^^^^^
                            sometimes incompatible) features are enabled
                            (though not all features are supported on 
NetBSD).
                            Currently only the following features are
                            supported:
                                  RESIZE       Prepare some reserved
                                               structures which enable 
future
                                               file system resizing.
                                  FTYPE        Store file types in 
directory
                                               entries to improve 
performance.
                                  SPARSESUPER  Prepare superblock 
backups for
                                               the fsck_ext2fs(8) 
utility on
                                               not all but sparse block
                                               groups.
                                  LARGEFILE    Enable files larger than 2G
                                               bytes.