Re: [gentoo-user] LVM for data drives but not the OS

[Joost Roeleveld]

On Saturday 09 April 2011 00:28:20 Dale wrote:
> OK.  I learned something.  Check this out:
>
> root@fireball / # df
> Filesystem           1K-blocks      Used Available Use% Mounted on
> << SNIP >>
> /dev/mapper/sdb--vg-test
>                        51606140  48910048     74652 100% /mnt/temp
> root@fireball / #
>
> This is what I am doing here.  As I posted a while ago, I created a 50Gb
> LV.  I attempted to copy about 75Gbs to it which filled it up but I
> wanted to make sure it would.  lol  Then I used lvextend -L100G
> /dev/mapper/sdb--vg-test to make it larger.  I read I could do the same
> thing with lvresize but the example I was reading showed lvextend.  This
> is what I got now:
>
> root@fireball / # lvdisplay
>    --- Logical volume ---
>    LV Name                /dev/sdb-vg/test
>    VG Name                sdb-vg
>    LV UUID                mixhOb-La6D-BwG4-Uz3l-P0ci-oGg5-YI3mN8
>    LV Write Access        read/write
>    LV Status              available
>    # open                 1
>    LV Size                100.00 GiB
>    Current LE             25600
>    Segments               1
>    Allocation             inherit
>    Read ahead sectors     auto
>    - currently set to     256
>    Block device           254:0
>
> root@fireball / #
>
> So, according to that it is 100Gbs which is what I wanted.  Thing was,
> it didn't work.  So, hmmmm.  Light bulb moment.  Resize the file system
> silly.  After that, success.  So, I created something that wasn''t big
> enough, filled it up, made it bigger, fixed the file system and now it
> is working.  All while online too.  That is the weird part.
>
> Still not comfy putting a OS on it but it is cool so far.

Nice :)

Btw, instead of specifying "final" size after resizing, you can actually tell 
it to "add" 20GB by doing:
lvrextend -L+20G /dev/sdb-vg/test

--
Joost