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I'm shredding files on large ext3 file systems (e.g. see this article for how I do this). In order to achieve this I need to mount the ext3 file systems without journaling. To most of them I get by with just unmounting them and re-mounting them as ext2. But some file systems can't be unmounted (e.g. /) and attempts to use "-o remount,data=writeback" fails with errors.

Is it possible to turn off journaling of a mounted ext3 file system without having to unmount it?

user9517
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Amos Shapira
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1 Answers1

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To the best of my knowledge you cannot change file system mount parameters without re-mounting it.

By the way, the article you refer to cites shred man page, which says: "In the case of ext3 file systems, the above disclaimer applies (and shred is thus of limited effectiveness) only in data=journal mode, which journals file data in addition to just metadata. In both the data=ordered (default) and data=writeback modes, shred works as usual."

Have a look at (or post) your /etc/fstab. Chances are you don't need to change journaling mode on the filesystem.

Paweł Brodacki
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  • mount -o remount will let you change some mount parameters on a mounted filesystem. For example, `mount -o remount,ro /` would remount your root filesystem read-only. I believe noatime or diratime can as well. Clearly `data=writeback` cannot be applied on a mounted filesystem, though. – idleyoungman Apr 30 '11 at 04:46