Re: A memory-based filesystem for the lazy [or impatient]

[Marcus Brinkmann]

On Thu, Dec 21, 2000 at 03:51:34PM -0500, Roland McGrath wrote:
> > On Thu, Dec 21, 2000 at 02:10:45AM -0500, Roland McGrath wrote:
> > > If you are going to take that approach, i.e. a memory-based disk rather
> > > than a memory-based filesystem, I would suggest adding a type to libstore.
> > 
> > But how do you format the store before it is used?
> 
> Just like any other, with mke2fs.
> 
>       settrans -c /dev/ramdisk /hurd/storeio -Tcopy zero:100M
>       mke2fs /dev/ramdisk
>       settrans -a /tmp /hurd/ext2fs /dev/ramdisk
> 
> It is true that there isn't a handy way to make:
> 
>       settrans -a /tmp /hurd/ext2fs -Tcopy zero:100M
> 
> do what you'd like.  This is unfortunate, since it is definitely better for
> performance to have the store implementation in ext2fs's libstore rather
> than in storeio's.

So what about a new weird store type, "run", with a command string as an
argument:

settrans -a /tmp /hurd/ext2fs -T run 'mke2fs ${store}:copy:zero:100M'

The run store would create a temporary translated node like storeio provides
it, let's say at /dev/fd/X (I don't know if we can use the /dev/fd namespace
for that), and substitute ${store} and run the command. When it completes,
the temporary node is destroyed and the now initialized copy store is passed
through. Is this creeping featurism?

Marcus

-- 
`Rhubarb is no Egyptian god.' Debian http://www.debian.org brinkmd@debian.org
Marcus Brinkmann              GNU    http://www.gnu.org    marcus@gnu.org
Marcus.Brinkmann@ruhr-uni-bochum.de
http://www.marcus-brinkmann.de