[linux-lvm] How do I use free PE?

[linux-lvm] How do I use free PE?

[Rod Rook]

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I've installed Fedora 10 on a 250GB SATA hard drive.
I want to use the unused portion (free PE= 4378, about 140GB), but I don't
know how I go about doing it.
I don't want to add it to VolGroup00, but I want it made accessible as a
general storage space.


> [root@localhost Documents]# pvdisplay /dev/sdb2
>
  --- Physical volume ---
  PV Name               /dev/sdb2
  VG Name               VolGroup00
  PV Size               232.69 GB / not usable 4.58 MB
  Allocatable           yes
  PE Size (KByte)       32768
  Total PE              7446
  Free PE               4376
  Allocated PE          3070

>   PV UUID               DBf14Y-SLFe-cwZy-m1O7-3Jw9-Xhdf-3u42iX
>
>

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Re: [linux-lvm] How do I use free PE?

[brem belguebli]

Hi,

your underlying disk /dev/sdb2 cannot be part of more than one volume
group, it'll have to be under VolGroup00.

When you say I don't want to add it to VolGroup00, you may be
confusing some concepts.

You certainly don't want to add free space under / (which is a
filesystem) on top of a Logical Volume (LogVol0) which itself is built
on top of your VolGroup00, isn't it ?

If so, you can create a new Logical volume (let's say
logvolgeneralstorage, man lvcreate) on top of VolGroup00 which will be
mounted on /otherstroragethanslash.

Everything is in the man pages (lvcreate, lvs, lvdisplay, mke[234]fs, fstab)

2009/10/23 Rod Rook <rod.rook@gmail.com>:
> I've installed Fedora 10 on a 250GB SATA hard drive.
> I want to use the unused portion (free PE= 4378, about 140GB), but I don't
> know how I go about doing it.
> I don't want to add it to VolGroup00, but I want it made accessible as a
> general storage space.
>
>>
>> [root@localhost Documents]# pvdisplay /dev/sdb2
>
> � --- Physical volume ---
> � PV Name�������������� /dev/sdb2
> � VG Name�������������� VolGroup00
> � PV Size�������������� 232.69 GB / not usable 4.58 MB
> � Allocatable���������� yes
> � PE Size (KByte)������ 32768
> � Total PE������������� 7446
> � Free PE�������������� 4376
> � Allocated PE��������� 3070
>>
>> � PV UUID�������������� DBf14Y-SLFe-cwZy-m1O7-3Jw9-Xhdf-3u42iX
>>
>
> _______________________________________________
> 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/
>

Re: [linux-lvm] How do I use free PE?

[Rod Rook]

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Thank you for your reply. I was thinking of using Gnome parted, but I wanted
to check to see if it can be used with LVM2 partitions.

On Fri, Oct 23, 2009 at 10:38 AM, brem belguebli
<brem.belguebli@gmail.com>wrote:

> Hi,
>
> your underlying disk /dev/sdb2 cannot be part of more than one volume
> group, it'll have to be under VolGroup00.
>
> When you say I don't want to add it to VolGroup00, you may be
> confusing some concepts.
>
> You certainly don't want to add free space under / (which is a
> filesystem) on top of a Logical Volume (LogVol0) which itself is built
> on top of your VolGroup00, isn't it ?
>
> If so, you can create a new Logical volume (let's say
> logvolgeneralstorage, man lvcreate) on top of VolGroup00 which will be
> mounted on /otherstroragethanslash.
>
> Everything is in the man pages (lvcreate, lvs, lvdisplay, mke[234]fs,
> fstab)
>
> 2009/10/23 Rod Rook <rod.rook@gmail.com>:
> > I've installed Fedora 10 on a 250GB SATA hard drive.
> > I want to use the unused portion (free PE= 4378, about 140GB), but I
> don't
> > know how I go about doing it.
> > I don't want to add it to VolGroup00, but I want it made accessible as a
> > general storage space.
> >
> >>
> >> [root@localhost Documents]# pvdisplay /dev/sdb2
> >
> >   --- Physical volume ---
> >   PV Name               /dev/sdb2
> >   VG Name               VolGroup00
> >   PV Size               232.69 GB / not usable 4.58 MB
> >   Allocatable           yes
> >   PE Size (KByte)       32768
> >   Total PE              7446
> >   Free PE               4376
> >   Allocated PE          3070
> >>
> >>   PV UUID               DBf14Y-SLFe-cwZy-m1O7-3Jw9-Xhdf-3u42iX
> >>
> >
> > _______________________________________________
> > 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/
>

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Re: [linux-lvm] How do I use free PE?

[Rod Rook]

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On Fri, Oct 23, 2009 at 9:59 AM, Rod Rook <rod.rook@gmail.com> wrote:

> Thank you for your reply. I was thinking of using Gnome parted, but I
> wanted to check to see if it can be used with LVM2 partitions.
>
> I am happy to report that I've successfully reduced the physical volume of
VolGroup00 by 160GB, which I don't think I will ever use with the volume
group. I left about 10GB for use by a snapshot volume. Since nobody had told
me that using gparted application is safe for what I was trying to do, I did
some more reading on the subject in other forums and made a backup of the
volume group before I plunged into this risky undertaking.

I used a System Rescue CD (version 1.3.1) to do the job. It comes with
gparted and LVM manager.
So, I can dare to say that one can reduce the physical volume of a volume
group provided there is a significant unused part exists.

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Re: [linux-lvm] How do I use free PE?

[Stuart D. Gathman]

On Fri, 23 Oct 2009, Rod Rook wrote:

> I've installed Fedora 10 on a 250GB SATA hard drive.
> I want to use the unused portion (free PE= 4378, about 140GB), but I don't
> know how I go about doing it.
> I don't want to add it to VolGroup00, but I want it made accessible as a
> general storage space.
>   PV Name               /dev/sdb2
>   VG Name               VolGroup00
>   PV Size               232.69 GB / not usable 4.58 MB
>   Total PE              7446
>   Free PE               4376
>   Allocated PE          3070

It already *is* part of VolGroup00.  To use it, you can:

1) increase the size of an existing filesystem, e.g. / on LogVol00.

  or
   
2) allocate another LV and create a filesystem on that.  

I don't use the GUI tools, but here is how you could do (2) on
the command line:

# lvcreate -L 100G -n data VolGroup00
# mke2fs -j -L/data /dev/VolGroup00/data
# mkdir /data

Edit /etc/fstab and add a line like the following:

LABEL=/data             /data                   ext3    noexec,nodev    1 0

# mount /data


Be sure to leave a gig or two of free space on VolGroup00 so that you
can make a snapshot of LogVol00 (or data) for backup:

# lvcreate -s -L1G -n LogVol00_snap VolGroup00/LogVol00
# mkdir /mnt/LogVol00
# mount -r /dev/VolGroup00/LogVol00_snap /mnt/LogVol00
# rsync -ravHX /mnt/LogVol00/ /path/to/directory/on/large/backup/disk
# lvremove VolGroup00/LogVol00_snap

-- 
	      Stuart D. Gathman <stuart@bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.