319 lines
4.7 KiB
HTML
319 lines
4.7 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>Reducing a logical volume</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="LVM HOWTO"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Common Tasks"
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HREF="commontask.html"><LINK
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REL="PREVIOUS"
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TITLE="Extending a logical volume"
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HREF="extendlv.html"><LINK
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REL="NEXT"
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TITLE="Migrating data off of a physical volume"
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HREF="migrateoffpv.html"></HEAD
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>LVM HOWTO</TH
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WIDTH="10%"
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ALIGN="left"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Chapter 11. Common Tasks</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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>Next</A
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="sect1"
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><H1
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CLASS="sect1"
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><A
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NAME="reducelv"
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></A
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>11.10. Reducing a logical volume</H1
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><P
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> Logical volumes can be reduced in size as well as increased.
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However, it is <EM
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>very</EM
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> important to remember to
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reduce the size of the file system or whatever is residing in the
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volume before shrinking the volume itself, otherwise you risk
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losing data.
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</P
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><P
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></P
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><OL
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TYPE="1"
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><LI
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><P
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> <STRONG
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> ext2
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</STRONG
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>
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</P
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><P
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> If you are using LVM 1 with ext2 as the file system
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then you can use the e2fsadm command mentioned
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earlier to take care of both the file system and
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volume resizing as follows:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="screen"
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> <B
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CLASS="command"
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># umount /home
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# e2fsadm -L-1G /dev/myvg/homevol
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# mount /home</B
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>
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</PRE
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></FONT
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></TD
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></TR
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></TABLE
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>
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<DIV
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CLASS="warning"
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><P
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></P
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><TABLE
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CLASS="warning"
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WIDTH="100%"
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BORDER="0"
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><TR
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><TD
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WIDTH="25"
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ALIGN="CENTER"
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VALIGN="TOP"
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><IMG
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SRC="../images/warning.gif"
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HSPACE="5"
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ALT="Warning"></TD
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><TH
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ALIGN="LEFT"
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VALIGN="CENTER"
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><B
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>LVM 2 Caveat</B
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></TH
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></TR
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><TR
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><TD
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> </TD
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><TD
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ALIGN="LEFT"
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VALIGN="TOP"
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><P
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> There is currently no e2fsadm equivalent for
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LVM 2 and the e2fsadm that ships with LVM 1
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does not work with LVM 2.
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</P
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></TD
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></TR
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></TABLE
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></DIV
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>
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</P
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><P
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> If you prefer to do this manually you must know the new size
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of the volume in blocks and use the following commands:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="screen"
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> <B
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CLASS="command"
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># umount /home
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# resize2fs /dev/myvg/homevol 524288
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# lvreduce -L-1G /dev/myvg/homevol
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# mount /home</B
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>
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</PRE
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></FONT
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></TD
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></TR
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></TABLE
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>
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</P
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></LI
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><LI
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><P
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> <STRONG
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> reiserfs
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</STRONG
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>
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</P
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><P
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> Reiserfs seems to prefer to be unmounted when shrinking
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="screen"
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> <B
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CLASS="command"
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># umount /home
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# resize_reiserfs -s-1G /dev/myvg/homevol
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# lvreduce -L-1G /dev/myvg/homevol
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# mount -treiserfs /dev/myvg/homevol /home</B
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>
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</PRE
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></FONT
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></TD
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></TR
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></TABLE
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>
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</P
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></LI
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><LI
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><P
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> <STRONG
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> xfs
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</STRONG
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>
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</P
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><P
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> There is no way to shrink XFS file systems.
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</P
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></LI
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><LI
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><P
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> <STRONG
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> jfs
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</STRONG
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>
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</P
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><P
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> There is no way to shrink JFS file systems.
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</P
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></LI
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></OL
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
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><TR
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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HREF="extendlv.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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WIDTH="34%"
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ALIGN="center"
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HREF="index.html"
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>Home</A
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><A
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HREF="migrateoffpv.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
|
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>Extending a logical volume</TD
|
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><TD
|
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="commontask.html"
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ACCESSKEY="U"
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>Up</A
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
|
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>Migrating data off of a physical volume</TD
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