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<a href="#NAME">NAME</a><br>
<a href="#SYNOPSIS">SYNOPSIS</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#EXIT STATUS">EXIT STATUS</a><br>
<a href="#BUGS">BUGS</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
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<a name="NAME"></a><h2>NAME</h2><p><font size=3>xfs_chver - change the version of a filesystem to enable the extent unwritten version.</p>
<a name="SYNOPSIS"></a><h2>SYNOPSIS</h2><p><font size=3><B>xfs_chver</B> <font size=3>[ <font size=3><B>-f</B> <font size=3>] <font size=3><B>-a</p>
</B><p><font size=3><B>xfs_chver</B> <font size=3>[ <font size=3><B>-f</B> <font size=3>] devices</p>
<a name="DESCRIPTION"></a><h2>DESCRIPTION</h2><p><font size=3><I>xfs_chver</I> <font size=3>uses the <font size=3><I>xfs_db</I> <font size=3>command to change the version of a filesystem to enable the extent unwritten version. This version is needed to close a security hole where a process can sometimes read old data off disk.</p>
<p><font size=3>The command must be run by the super-user. The command either does all devices found in <font size=3><I>fstab(5)</I> <font size=3>when the -a option is used or the given devices from the second form above.</p>
<p><font size=3>The command either does the changes or creates scripts which can later be applied using the <font size=3><I>xfs_db</I> <font size=3>command. If the -f option is used, scripts are created and not applied. Without the -f option, the scripts are created, applied using <font size=3><I>xfs_db,</I> <font size=3>and removed.</p>
<p><font size=3>Devices that are mounted cannot be converted. This is always true for the root filesystem. Administrators must unmount filesystems before <font size=3><I>xfs_chver</I> <font size=3>or <font size=3><I>xfs_db</I> <font size=3>can convert the version. If a device being converted is found in <font size=3><I>/etc/mtab</I><font size=3>, the conversion is not attempted and an appropriate message is printed. It is safe to run this command on mounted devices as they are just skipped.</p>
<p><font size=3>It is also safe to re-run the command multiple times on the same devices. If the device is already converted or inaccessible, a simple message is printed and the command continues with the next device.</p>
<p><font size=3>The -f option causes the xfs_chver command to reduce error checking and create file(s) which can be passed to <font size=3><I>xfs_db.</I> <font size=3>These files are created in the current directory in the form <device>.xfs_chver. These files can be applied to the filesystem, invoke the following command:</p>
<p><span style=" text-indent: 0.6500in;"></span><font size=3>xfs_db -x <device> < <device>.xfs_chver<br>
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<p><font size=3>When the -f options is given, the following conditions are not checked for the device(s):</p>
<p><span style=" text-indent: 0.6500in;"></span><font size=3>o - is the device the root filesystem,</p>
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<p><font size=3>o - is the device mounted,</p>
<p><font size=3>o - can the user write to the device.</p>
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<p><font size=3>When the -f option is not used, the device is checked with /dev/root. If a device has the same <font size=3><I>st_rdev,</I> <font size=3>as the root device, i.e. /dev/root, the conversion is not attempted and a message is printed. The root can only be converted if another filesystem is used as a root and the "current root" filesystem is accessed from the other root.</p>
<p><font size=3>Another alternative to convert the root is to use the -f option. The created file should be saved on the root to con- vert. Next, boot the miniroot and mount the root to convert. Next, copy the file just created with the -f option and the <font size=3><I>xfs_db</I> <font size=3>command (usually found in /usr/sbin/xfs_db) onto the mini root. Now, unmount the root to convert. Then run the command:</p>
<p><span style=" text-indent: 0.6500in;"></span><font size=3>xfs_db -x <device> < <script></p>
<p><font size=3>where <device> is the root device and <script> is the file created with the -f option above.</p>
<a name="EXIT STATUS"></a><h2>EXIT STATUS</h2><p><font size=3>A status of 1 is returned if the usage is incorrect, e.g. -a is used with a device name or an unrecognized parameter is detected. All other cases return a status of 0, even if a filesystem is skipped.</p>
<a name="BUGS"></a><h2>BUGS</h2><p><font size=3>The xfs_db man page does not exist, yet.</p>
<p><font size=3>cat <script> | xfs_db -x <device> does not work. Use xfs_db -x <device> < <script>.</p>
<a name="SEE ALSO"></a><h2>SEE ALSO</h2><p><font size=3>xfs_db(8), fstab(5), mkfs.xfs(8), xfs(5).<br>
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