rw ramdisk with ro backend?

rw ramdisk with ro backend?

Post by Michael Ossma » Mon, 25 Nov 2002 15:57:17



I'm trying to find a way to mount a filesystem on a
read-only medium in read-write mode (with changes
stored only in RAM and lost upon umount).  Does
anyone know a way to do this?

Thanks.

 
 
 

rw ramdisk with ro backend?

Post by David Efflan » Mon, 25 Nov 2002 18:03:57



Quote:> I'm trying to find a way to mount a filesystem on a
> read-only medium in read-write mode (with changes
> stored only in RAM and lost upon umount).  Does
> anyone know a way to do this?

You set up a ramdisk, copy the data to it, and away you go.  Example of

case I backed it up every 2 hrs from cron):

# set up ramdisk for setiathome
/bin/dd if=/dev/zero of=/dev/ram bs=1k count=2048
/sbin/mke2fs -vm0 /dev/ram 2048
/bin/mount -t ext2 /dev/ram /home/efflandt/seti-ram
cp /home/efflandt/setiathome/* /home/efflandt/seti-ram
/bin/chmod 755 /home/efflandt/seti-ram
/bin/chown -R efflandt.efflandt /home/efflandt/seti-ram

--
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rw ramdisk with ro backend?

Post by Michael Ossma » Tue, 26 Nov 2002 01:37:19



> You set up a ramdisk, copy the data to it, and away you go.

The reason I don't want to do it that way is that I would
like to use very large filesystems (compared to available
RAM).  There will only be small, incremental changes to
unpredictable files, but the sum of the changes would never
approach the limit of available RAM.

I'm envisioning something like a standard filesystem driver
(like ext2) which gets lets me mount a read-only medium
read-write and then never tries to flush the buffer-cache.

 
 
 

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When booting the hd using lilo it said I needed to mount
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