Re: [linux-lvm] LVM Problems :)

[Heinz Mauelshagen <mauelshagen@redhat.com>]

On Sun, Feb 15, 2004 at 12:09:46PM -0600, Ken Fuchs wrote:
> Heinz Mauelshagen wrote:
> 
> >the missing task was to shrink the LV.
> 
> Yes, I know.  The following does that (indirectly):
> 
> # resize_ext2 /<LV path>

That would grow the FS back to the LV size, not shrink it down to the FS size
which is the intention in this particular case.

> 
> Without the size argument this command resizes the ext2 or ext3
> filesystem to fit the LV (obviating the need to calculate a new size of
> the LV that fits the filesystem size which may not even be optimal if
> the filesystem size is not a multiple of the extent size).
> 
> # e2fsadm --size <desired size> /<LV path>
> 
> or 
> 
> # e2fsadm --extents <desired size in extents> /<LV path>
> 
> Used to resize the LV and ext2 or ext3 filesystem in a single step.
> 
> The whole point of the above two step sequence is to avoid the
> possibility of miscalculating the new size of the LV when using
> lvreduce(8).  It is a safer, though longer way to effectively do a
> lvreduce(8) or lvextent(8) when the contained filesystem is ext2 or
> ext3.

I know. I wrote it ;)

The FS was smaller than the LV already due to some unknown problem.

> 
> In my opinion, this is a better solution when one is uncertain about the
> correct size to use with lvreduce(8) to shrink the LV to fit either an
> ext2 or ext3 filesystem.

Absolutely users should prefer using e2fsadm doing LV + ext2/ext3 resizing
(presumably they can, because the FS and LV have the same size).

Regards,
Heinz    -- The LVM Guy --


> 
> The previous message is quoted below.
> 
> Sincerely,
> 
> Ken Fuchs <kfuchs@winternet.com>
> 
> 
> >On Fri, Feb 13, 2004 at 03:23:41PM -0600, Ken Fuchs wrote:
> >> Heinz Mauelshagen wrote:
> >> 
> >> >the size of your filesystem and logical volume differs already.
> >> >That's why e2fsadm fails.
> >> >Did you eventually run resize2fs in order to shrink the filesystem ?
> >> 
> >> >Your logical volume size is 1091456MB (32MB/PE * 34108 PE) but your
> >> >filesystem size is 963584GB (941GB * 1024MB/GB; check with
> >> >"tune2fs -l" and look for the block count and block size to calculate
> >> >this correctly).
> >> 
> >> >In case the result shows, that your filesystem is already smaller than the LV,
> >> >lvreduce the logical volume appropriately.
> >> 
> >> >Use the block count * block size result and round it up to the next PE!
> >> 
> >> To avoid an error in calculating the correct number of logical extents,
> >> and possibly doing an lvreduce(8) to a size smaller than the filesystem:
> >> 
> >> Use resize_ext2(8) without a size argument.  This will resize the ext2
> >> or ext3 filesystem to be the same size as the logical volume containing
> >> it.  After doing this, e2fsadm(8) can be used to resize the filesystem
> >> and logical volume "simultaneously" to any desired size (that can
> >> contain the filesystem's data).
> >> 
> >> Sincerely,
> >> 
> >> Ken Fuchs <kfuchs@winternet.com>
> >> 
> >> _______________________________________________
> >> linux-lvm mailing list
> >> linux-lvm@redhat.com
> >> https://www.redhat.com/mailman/listinfo/linux-lvm
> >> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> >
> >-- 
> >
> >Regards,
> >Heinz    -- The LVM Guy --
> >
> >*** Software bugs are stupid.
> >    Nevertheless it needs not so stupid people to solve them ***
> >
> >=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> >
> >Heinz Mauelshagen                                 Red Hat, Inc.
> >Consulting Development Engineer                   Am Sonnenhang 11
> >                                                  56242 Marienrachdorf
> >                                                  Germany
> >Mauelshagen@RedHat.com                            +49 2626 141200
> >                                                       FAX 924446
> >=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> >
> >_______________________________________________
> >linux-lvm mailing list
> >linux-lvm@redhat.com
> >https://www.redhat.com/mailman/listinfo/linux-lvm
> >read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> >
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

*** Software bugs are stupid.
    Nevertheless it needs not so stupid people to solve them ***

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Heinz Mauelshagen                                 Red Hat, Inc.
Consulting Development Engineer                   Am Sonnenhang 11
                                                  56242 Marienrachdorf
                                                  Germany
Mauelshagen@RedHat.com                            +49 2626 141200
                                                       FAX 924446
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