[TUHS] Device special files
Bakul Shah
bakul at bitblocks.com
Thu Feb 8 09:06:24 AEST 2018
On Wed, 07 Feb 2018 17:05:05 -0500 Clem Cole <clemc at ccc.com> wrote:
>
> One of the lines I have had about UNIX development is the number if
> namespaces its has. If you try to develop something like Single System
> Image Clusters (check out OpenSSI.org) you'll hit all of the namespaces.
>
> Let me see how many I can remember quickly..
>
> 1. file system
> 2. per device inumbers for storage
> 3. device major numbers
> 4. per device minor numbers
> 5. pid
> 6. gid
> 7. sockets
> 8. port numbers within sockets per protocol
> 9. system V semaphores
> 10. system V shared memory
Most all of these are intrinsic or unavoidable. You can use
strings instead of table indices but still the same. And some
of these have sub-namespaces. This is why plan9's mountable
namespaces is such a neat solution. Too bad Unix just stole
/proc & /dev/fd.... And this can be added
devfs is too big a sledgehammer (+ it needs /etc/devfs.conf
for permissions and ownership using its own DSL). For example,
names of devices not accessible in a jail still show up there.
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