12:53 p.m.
zerofree is a package that can take an ext2 (only?) filesystem, work
out what parts of the filesystem are not used, and either zero them or
sparsify them.
This was useful in about 2009 when I added it to Fedora. However
nowadays it's more convenient to use the equivalent kernel
functionality (via the ‘fstrim’ command or equivalent ioctls). The
kernel functionality also works correctly for other filesystem types.
There's also a more serious data safety issue: Although this probably
works OK for ext2 since that format is frozen in time, it probably
corrupts ext4 filesystems containing features that it doesn't know
about.
It is for these reasons that I don't think you should use this package
and I intend to retire it unless anyone says otherwise.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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12:58 p.m.
Am 18.02.2018 um 19:53 schrieb Richard W.M. Jones:
zerofree is a package that can take an ext2 (only?) filesystem, work
out what parts of the filesystem are not used, and either zero them or
sparsify them.
This was useful in about 2009 when I added it to Fedora. However
nowadays it's more convenient to use the equivalent kernel
functionality (via the ‘fstrim’ command or equivalent ioctls). The
kernel functionality also works correctly for other filesystem types.
There's also a more serious data safety issue: Although this probably
works OK for ext2 since that format is frozen in time, it probably
corrupts ext4 filesystems containing features that it doesn't know
about.
It is for these reasons that I don't think you should use this package
and I intend to retire it unless anyone says otherwise
fstrim don't work on VMware guests stored on NFS
fstrim don't work on VMware guests on VMFS lower than 6.0
fstrim don't work on Proxmox with SATA vritual adapters
so back to the good old:
nice -n 19 dd status=progress if=/dev/zero bs=64M of=zero.fill bs=64M
sync
nice -n 19 rm -f zero.fill
2:19 p.m.
On Sun, 18 Feb 2018, Richard W.M. Jones wrote:
There's also a more serious data safety issue: Although this
probably
works OK for ext2 since that format is frozen in time, it probably
corrupts ext4 filesystems containing features that it doesn't know
about.
It is for these reasons that I don't think you should use this package
and I intend to retire it unless anyone says otherwise.
Last time I used it (a year ago?) it worked properly for ext3 and ext4, but
on RHEL rather on Fedora. Not sure which features you are talking about in
detail, but bumping zerofree from 1.0.3 to 1.1.0 would add 64 bit block no.
support at least...
Regards,
Robert
2:47 p.m.
On Sun, Feb 18, 2018 at 09:19:09PM +0100, Robert Scheck wrote:
On Sun, 18 Feb 2018, Richard W.M. Jones wrote:
> There's also a more serious data safety issue: Although this probably
> works OK for ext2 since that format is frozen in time, it probably
> corrupts ext4 filesystems containing features that it doesn't know
> about.
>
> It is for these reasons that I don't think you should use this package
> and I intend to retire it unless anyone says otherwise.
Last time I used it (a year ago?) it worked properly for ext3 and ext4, but
on RHEL rather on Fedora. Not sure which features you are talking about in
detail, but bumping zerofree from 1.0.3 to 1.1.0 would add 64 bit block no.
support at least...
Would fstrim or virt-sparsify have worked for you?
I feel that supporting something which has been rejected by the
e2fsprogs community is difficult, especially when it concerns data
integrity.
If you wish to take it over, I can orphan it instead.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine. Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/
5:40 a.m.
On Mon, Feb 19, 2018 at 11:57:03AM +0100, Robert Scheck wrote:
Hello Richard,
On Sun, 18 Feb 2018, Richard W.M. Jones wrote:
> If you wish to take it over, I can orphan it instead.
I'm happy to take zerofree.
I *think* I've pressed the right buttons to give you the project ...
There is only one known problem, it needs:
BuildRequires: gcc
added to the spec file.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW
3:21 a.m.
Rich,
Thanks for packaging zerofree. It's been great to be able to install
my own software without having to build it.
Richard W.M. Jones wrote:
zerofree is a package that can take an ext2 (only?) filesystem, work
out what parts of the filesystem are not used, and either zero them or
sparsify them.
It works for ext2, ext3 and ext4. It zeros free blocks; sparsifying
is a different issue.
There's also a more serious data safety issue: Although this
probably
works OK for ext2 since that format is frozen in time, it probably
corrupts ext4 filesystems containing features that it doesn't know
about.
To the best of my knowledge it does not corrupt ext4 filesystems.
The only thing zerofree cares about is free blocks. Filesystem
features that affect files, directories or inodes are irrelevant to
zerofree.
zerofree get its information about free blocks from the ext2fs library.
However free blocks may be represented on disk the library provides the
abstraction necessary to access them.
I feel that supporting something which has been rejected by the
e2fsprogs community is difficult, especially when it concerns data
integrity.
I don't consider zerofree to have been rejected by the e2fsprogs
community. Due to my fear of rejection it has never been submitted for
their consideration.
Ron
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6 comments
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participants (4)
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Reindl Harald -
Richard W.M. Jones -
Robert Scheck -
Ron Yorston