On Mon, 6 Mar 2006 11:17:35 +0000
Greig A Cowan <[log in to unmask]> wrote:
> And there was a very interesting talk given by a guy from PIC about
> how they manage the problem of writing small files to tape using
> ISOs:
>
> http://indico.cern.ch/contributionDisplay.py?contribId=265&sessionId=6&confId=048
>
I just had a look at this and felt that this was almost exactly
equivalent to condors NEST storage element. This uses "lots", which are
loop back file systems of ext2 which may or may not have advantages over
ISO images. It is interesting to see this come up again and it seems
like a practical "file bundling" approach, but does have issues such as
the maximum number of loop back file systems supported per host.
The overhead of copying to loop back file systems cannot be overlooked
too but all in all an interesting retake on an old idea. Is anyone
planing on running with this idea?
ISO's are ment to be read only while ext2 is read write this is the
main difference. See below for inconsistent Linux reaction to this.
Regards
Owen
#mount /tmp/testsdfsdf.iso /mnt/tmp/ -o loop
#mount
/dev/hda1 on / type ext3 (rw,errors=remount-ro)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
/dev/hda4 on /mnt/tmp type ext3 (rw,errors=remount-ro)
/dev/hdb1 on /home type ext3 (rw,errors=remount-ro)
usbfs on /proc/bus/usb type usbfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/tmp/testsdfsdf.iso on /mnt/tmp type iso9660 (rw,loop=/dev/loop0)
#rm /mnt/tmp/netscapewrap.sh
rm: cannot remove `/mnt/tmp/netscapewrap.sh': Read-only file system
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