Messages in this thread | | | From | Rob Landley <> | Subject | Re: document ext3 requirements | Date | Sun, 4 Jan 2009 21:22:35 -0600 |
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On Sunday 04 January 2009 13:21:06 Geert Uytterhoeven wrote: > I think most people get shocked when they discover that mounting something > read-only may actualy write to the media. This is a bit unexpected (hey, if > I mount `read-only', I expect that no writes will happen), as it behaved > differently before the introduction of journalling.
Is this an unreasonable use case:
kill -STOP $(pidof qemu) mount -o loop,ro hdb.img blah cp blah/thingy thingy umount blah kill -CONT $(pidof qemu)
Currently, if your loopback mount is -t ext3 it'll write to the block device, and if your mount is -t ext2 it'll refuse to work on an unclean ext3 filesystem, even if it's read only. (But it _will_ work on an unclean ext2 filesystem.)
My theory when I first found out about this was "the filesystem developers hate me personally".
Rob
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