Re: Hurd and Unix/Linux and Plan9 features

[Ivan Shmakov]

> > > > > "S" == Shams  <shams@orcon.net.nz> writes:

       I don't participate in GNU/Hurd development, and I don't mean my
       answers to be authoritative, but...

S> Hi, 1. Will hurd still retain the symbolic link and hard link
S> concept of Unix/Linux?

       First of all, it should be noted that there're /two/ Hurds --
       one is based on GNU Mach microkernel (and there're hosts on
       which GNU/Hurd system is running currently), and the other --
       HurdNG, which is just being planned.

       While currently available GNU/Hurd system behaves in many
       respects like a GNU/Linux system (and, in fact, shares a vast
       amount of source code with the latter), HurdNG differences might
       be much more significant.  However, my opinion is that already
       developed code, when appears apt, should be used, so various
       features available in UNIX or GNU/Linux should be provided as
       well as the native HurdNG features.  Probably, by means of POSIX
       emulation layer of some sort.

S> * Also will it support hard links for directories?

       This problem was discussed on the list some time ago.  My
       opinion that it /shouldn't/ be done.  If one thinks of a
       directory as a mapping of file names to actual file objects, and
       of hard links as the alternate names to a file (directory)
       object, then it becomes hard to decide, which file (directory)
       the `..' name is mapped to?

S> * Can tranlators be symbolic linked or hard linked?

S> * Currently in *Nix one has to use the find command to find a list
S> of all symbolic links and hard links. I am wondering if this will be
S> made much more easier in hurd?

       I don't understand.  Using $ find command to find symbolic links
       doesn't seem to be hard at all:

$ find -type s

       On the other hand, what do you mean by finding hard links?  When
       I do, e. g.:

$ touch a
$ ln a b
$

       Which one I should find, `a' or `b'?  From the point of UNIX,
       they're completely equal and both designate the very same file.

S> 2. Will it support the Linux LVM concept?

       Looks like with HurdNG's ``space banks'', things would be even
       better than with the Linux LVM.

S> 3. Also what features does Hurd borrow or enhance from the Plan 9
S> OS.  I mean for example Plan 9 abstracts everything as files.

       The filesystem is itself to be implemented on top of more
       general RPC interface in HurdNG.  It would allow every user (or
       even every program) to ``have'' it's own filesystem.

S> Will/does Hurd support such concept (its sees everthing as files) or
S> is this just achievabal by existing or writing custom translators?

       I think so.

S> Also Debian/Philip thanks for releasing the K14 cd's.