On Tue, Sep 22, 2009 at 10:42 AM, Graduate Studies Web Master <
[email protected]> wrote:

> >-----Original Message-----
> >From: [email protected] [mailto:uug-list-
> >[email protected]] On Behalf Of Stuart Jansen
> >Sent: Thursday, September 17, 2009 5:22 PM
> >To: BYU Unix Users Group
> >Subject: Re: [uug] LVN Help
> >
> >On Thu, 2009-09-17 at 17:07 -0600, Graduate Studies Web Master wrote:
> >> A few days ago I tried to increase the size of the vg-var directly
> >> using lvextend, but it said I needed  32 extents when 0 were
> >> available. I’m not sure where to go from here. Any ideas?
> >
> >It would be nice to see the output of vgdisplay. Sounds like you're
> >space has been used somewhere else. Without knowing where, it's hard to
> >how to proceed.
> >
>
> Thanks for your help everyone. My server service contact told me he thought
> there were 50GB that were unallocated yet that I could use, but I still
> can't find them.
>
> When I run fdisk -l, this is what I get:
>
>   Disk /dev/sda: 21.4 GB, 21474836480 bytes
>   255 heads, 63 sectors/track, 2610 cylinders
>   Units = cylinders of 16065 * 512 = 8225280 bytes
>
>   Device Boot      Start         End      Blocks   Id  System
>   /dev/sda1   *           1          13      104391   83  Linux
>   /dev/sda2              14        2610    20860402+  8e  Linux LVM
>
>   Disk /dev/sdb: 53.6 GB, 53687091200 bytes
>   255 heads, 63 sectors/track, 6527 cylinders
>   Units = cylinders of 16065 * 512 = 8225280 bytes
>
>   Disk /dev/sdb doesn't contain a valid partition table
>
> That should show me all the disks I have at my disposal right? And
> pvdisplay gives me:
>
>  --- Physical volume ---
>  PV Name               /dev/sda2
>  VG Name               vg
>  PV Size               19.89 GB / not usable 19.49 MB
>  Allocatable           yes (but full)
>  PE Size (KByte)       32768
>  Total PE              636
>  Free PE               0
>  Allocated PE          636
>  PV UUID               Tc3LZt-mYmJ-V124-Qz5c-UJed-bj5f-6Y9xk7
>
>  --- Physical volume ---
>  PV Name               /dev/sdb
>  VG Name               vg
>  PV Size               50.00 GB / not usable 32.00 MB
>  Allocatable           yes (but full)
>  PE Size (KByte)       32768
>  Total PE              1599
>  Free PE               0
>  Allocated PE          1599
>  PV UUID               JBNdp2-rZmF-jfEv-qFVa-eOPK-EU7A-Tz9s1L
>
> Which, to me, suggests all the disk space is allocated.
>
> But, I have another question. I sent the below output previously for df -h
> and lvmdiskscan. I'm curious if the /dev/mapper/vg-... references (e.g.
> vg-usr, vg-home, vg-var etc.) in df -h are actually different than the
> /dev/vg/... references to the same names (e.g. usr, home, var, etc.) in
> lvmdiskscan or if they refer to the same thing. It is a little confusing to
> me.
>
> Again, thanks for the help.
>
> Filesystem                       Size      Used     Avail   Use% Mounted on
> /dev/mapper/vg-root     2.0G     651M    1.3G    35%       /
> /dev/mapper/vg-home   992M   34M     908M   4%        /home
> /dev/mapper/vg-usr       5.9G     3.0G     2.6G     54%      /usr
> /dev/mapper/vg-tmp     2.0G      207M   1.7G     11%      /tmp
> /dev/mapper/vg-var      2.0G      1.8G     103M    95%     /var
> /dev/sda1                       99M       19M     76M     20%     /boot
> tmpfs                              1006M    0          1006M   0%
> /dev/shm
>
> # lvmdiskscan
>  /dev/ramdisk  [       16.00 MB]
>  /dev/root     [        2.00 GB]
>  /dev/ram      [       16.00 MB]
>  /dev/sda1     [      101.94 MB]
>  /dev/vg/home  [        1.00 GB]
>  /dev/ram2     [       16.00 MB]
>  /dev/sda2     [       19.89 GB] LVM physical volume
>  /dev/vg/usr   [        6.00 GB]
>  /dev/ram3     [       16.00 MB]
>  /dev/vg/tmp   [        2.00 GB]
>  /dev/ram4     [       16.00 MB]
>  /dev/vg/var   [        2.00 GB]
>  /dev/ram5     [       16.00 MB]
>  /dev/vg/swap0 [        2.00 GB]
>  /dev/ram6     [       16.00 MB]
>  /dev/vg/opt   [       54.84 GB]
>  /dev/ram7     [       16.00 MB]
>  /dev/ram8     [       16.00 MB]
>  /dev/ram9     [       16.00 MB]
>  /dev/ram10    [       16.00 MB]
>  /dev/ram11    [       16.00 MB]
>  /dev/ram12    [       16.00 MB]
>  /dev/ram13    [       16.00 MB]
>  /dev/ram14    [       16.00 MB]
>  /dev/ram15    [       16.00 MB]
>  /dev/sdb      [       50.00 GB] LVM physical volume
>  8 disks
>  16 partitions
>  1 LVM physical volume whole disk
>  1 LVM physical volume
>

Yes, /dev/mapper/vg-lv is the same thing as /dev/vg/lv you can use either
interchangably when issuing LVM commands. I'd use /dev/mapper/vg-lv for
anything outside of LVM. I'm used to using it to absract what the actual
volume is in multi-path for instance.

The big thing in determining where your space may be is not pvdisplay but
vgdisplay. The reason for this is that pvdisplay shows which disks have been
assigned to volume groups. Once a disk has been assigned to a vg, it will
show as being used even if there is no partition on it. Using vgdisplay will
show you how many PE (Physical Extents) are being used by logical volumes
(lv). If you have free space, I suspect it is there. You can use the free
space to extend a volume or create a new one. Send us the output of
vgdisplay.

Robert LeBlanc
Life Sciences & Undergraduate Education Computer Support
Brigham Young University
--------------------
BYU Unix Users Group 
http://uug.byu.edu/ 

The opinions expressed in this message are the responsibility of their
author.  They are not endorsed by BYU, the BYU CS Department or BYU-UUG. 
___________________________________________________________________
List Info (unsubscribe here): http://uug.byu.edu/mailman/listinfo/uug-list

Reply via email to