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><H1
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><A
NAME="buildlvmmod"
></A
>6.2. Build the LVM 1 kernel module</H1
><P
> To use LVM 1 you will have to build the LVM 1 kernel module
(recommended), or if you prefer rebuild the kernel with the
LVM 1 code statically linked into it.
</P
><P
> Your Linux system is probably based on one of the popular
distributions (eg., Red Hat, SuSE, Debian) in which case it
is possible that you already have the LVM 1 module. Check
the version of the tools you have on your system. You can do
this by running any of the LVM command line tools with the
'-h' flag. Use <B
CLASS="command"
>pvscan -h</B
> if you don't
know any of the commands. If the version number listed at
the top of the help listing is LVM 1.0.8, <STRONG
>use your current setup</STRONG
> and avoid the
rest of this section.
</P
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="buildlvmpatch"
></A
>6.2.1. Building a patch for your kernel</H2
><P
> In order to patch the linux kernel to support LVM 1.0.8, you must
do the following:
<P
></P
><OL
TYPE="1"
><LI
><P
> Unpack LVM 1.0.8 </P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="screen"
> <B
CLASS="command"
> # tar zxf lvm_1.0.8.tar.gz </B
>
</PRE
></FONT
></TD
></TR
></TABLE
></LI
><LI
><P
> Enter the root directory of that version. </P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="screen"
> <B
CLASS="command"
> # cd LVM/1.0.8 </B
>
</PRE
></FONT
></TD
></TR
></TABLE
></LI
><LI
><P
> Run configure</P
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><TD
><FONT
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><PRE
CLASS="screen"
> <B
CLASS="command"
> # ./configure </B
>
</PRE
></FONT
></TD
></TR
></TABLE
><P
> You will need to pass the option
<TT
CLASS="option"
>--with-kernel_dir</TT
> to configure if your
linux kernel source is not in
<TT
CLASS="filename"
>/usr/src/linux</TT
>.
(Run <B
CLASS="command"
>./configure --help</B
> to see all the
options available)
</P
></LI
><LI
><P
> Enter the PATCHES directory</P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="screen"
> <B
CLASS="command"
> # cd PATCHES </B
>
</PRE
></FONT
></TD
></TR
></TABLE
></LI
><LI
><P
> Run 'make'</P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="screen"
> <B
CLASS="command"
># make </B
>
</PRE
></FONT
></TD
></TR
></TABLE
><P
> You should now have a patch called
<TT
CLASS="filename"
>lvm-1.0.8-$KERNELVERSION.patch</TT
> in the
patches directory. This is the LVM kernel patch referenced
in later sections of the howto.
</P
></LI
><LI
><P
> Patch the kernel</P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="screen"
> <B
CLASS="command"
> # cd /usr/src/linux ; patch -pX < /directory/lvm-1.0.8-$KERNELVERSION.patch </B
>
</PRE
></FONT
></TD
></TR
></TABLE
></LI
></OL
>
</P
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="buildlvm1-2.2"
></A
>6.2.2. Building the LVM module for Linux 2.2.17+</H2
><P
> The 2.2 series kernel needs to be patched before you can start
building, look elsewhere for instructions on how to patch your
kernel.
</P
><P
> Patches:
</P
><P
></P
><OL
TYPE="1"
><LI
><P
> <STRONG
>rawio patch</STRONG
>
</P
><P
> Stephen Tweedie's raw_io patch which can be found at
<A
HREF="http://www.kernel.org/pub/linux/kernel/people/sct/raw-io"
TARGET="_top"
>http://www.kernel.org/pub/linux/kernel/people/sct/raw-io</A
>
</P
></LI
><LI
><P
> <STRONG
>lvm patch</STRONG
>
</P
><P
> The relevant LVM 1 patch which should be built out
of the PATCHES sub-directory of the LVM
distribution. More information can be found in
<A
HREF="buildlvmmod.html#buildlvmpatch"
>Section 6.2.1</A
>, Building a patch
for your kernel.
</P
></LI
></OL
><P
> Once the patches have been correctly applied, you need to make sure
that the module is actually built, LVM 1 lives under the block
devices section of the kernel config, you should probably request
that the LVM /proc information is compiled as well.
</P
><P
> Build the kernel modules as usual.
</P
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="buildlvm1-2.4"
></A
>6.2.3. Building the LVM modules for Linux 2.4</H2
><P
> The 2.4 kernel comes with LVM 1 already included although
you should check at the Sistina web site for updates,
(eg. v2.4.9 kernels and earlier must have the <A
HREF="buildlvmmod.html#buildlvmpatch"
>latest LVM 1 patch</A
> applied ).
When configuring your kernel look for LVM 1 under <STRONG
>Multi-device support (RAID and
LVM)</STRONG
>. LVM 1 can be compiled into the kernel or as
a module. Build your kernel and modules and install then
in the usual way. If you chose to build LVM as a module it
will be called <TT
CLASS="filename"
>lvm-mod.o</TT
>
</P
><P
> If you want to use snapshots with ReiserFS, make sure you apply the
<TT
CLASS="filename"
>linux-2.4.x-VFS-lock</TT
> patch (there are copies
of this in the
<TT
CLASS="filename"
>LVM/1.0.8/PATCHES</TT
> directory.)
</P
></DIV
><DIV
CLASS="sect2"
><H2
CLASS="sect2"
><A
NAME="checkproc"
></A
>6.2.4. Checking the proc file system</H2
><P
> If your kernel was compiled with the /proc file system (most are)
then you can verify that LVM is present by looking for a /proc/lvm
directory. If this doesn't exist then you may have to load the
module with the command
</P
><TABLE
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><TR
><TD
><FONT
COLOR="#000000"
><PRE
CLASS="screen"
> <B
CLASS="command"
> # modprobe lvm-mod </B
>
</PRE
></FONT
></TD
></TR
></TABLE
><P
> If <TT
CLASS="filename"
> /proc/lvm </TT
> still does not exist then check
your kernel configuration carefully.
</P
><P
> When LVM is active you will see entries in
<TT
CLASS="filename"
>/proc/lvm</TT
> for all your physical volumes,
volume groups and logical volumes. In addition
there is a <SPAN
CLASS="QUOTE"
>"file"</SPAN
> called
<TT
CLASS="filename"
>/proc/lvm/global</TT
> which gives a summary
of the LVM status and also shows just which version of the LVM
kernel you are using.
</P
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