Resizing LVM -

Sun Feb 2 21:01:22 UTC 2014

On 02/02/14 15:15, Chris Murphy wrote:
> On Feb 2, 2014, at 8:56 AM, "Bob Goodwin - Zuni, Virginia, USA" <bobgoodwin at wildblue.net> wrote:
>
>> I have a computer with a 1TB drive taken up completely with an F-19 system. I'd like to squeeze that down and make room for anther Linux partition but I can't seem to get started.
>>
>> I have an F-19 DVD that I have been trying to use for booting into the "rescue" mode but I may not be doing it right. I can stumble through until I get a point where it says "An error occurred trying to mount some or all of your system. Some of it may be mounted under /mnt/sysimage. Press return to get a shell."
>>
>> That gets another box offering: start shell, fakd, reboot.
>>
>>  From the shell I do chroot /mnt/sysimage.
>>
>> Then ls lists a familiar list of directories, however there is nothing in those directories e.g. home, root, etc.
>>
>> At that point I am stumped!
>>
>>
> Yet another example of how LVM by default is unhelpful for mortal users.
>
> Is this BIOS or UEFI? Is the partition scheme MBR or GPT? Please show what layout you currently have, and what layout your other Linux installation requires.
It's good old DELL computer built before UEFI became common. I assume 
MBR. Presently it has only Fedora-19, I believe I installed it from the 
XFCE Live spin.

I would like to install Fedora-20 and Centos 6.5 while keeping the 
present install. I will probably avoid the LVM next for F-20 and Centos 
if I can.
>   Please provide the results from:
>
> parted -s /dev/sdX u s p

[root at box7 bobg]# parted -s /dev/sda u s p
Model: ATA SAMSUNG HD103SJ (scsi)
Disk /dev/sda: 1953525168s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number  Start     End          Size         Type     File system Flags
  1      2048s     1026047s     1024000s     primary  ext4 boot
  2      1026048s  1953523711s  1952497664s  primary lvm

[root at box7 bobg]# fdisk -l /dev/sda

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes, 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000e1c28

    Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1026047      512000   83  Linux
/dev/sda2         1026048  1953523711   976248832   8e  Linux LVM

>
> And for the new layout, I'm thinking it needs its own /boot partition and will use LVM for everything else, yes?
>
> What have you done so far? You shouldn't have empty directories.
I haven;t changed anything so far, just tried to follow a set of 
instructions I Googled. Stopped since I can't get the Linux Rescue to 
work or at least produce a result that I have some confidence in. Dunno 
why those directories show as empty? They are still good, the system 
works. I have ssh'd into it to copy the results you requested.
>
>> Suggestions solicited, maybe I should just give up and re-install?
> It's a lot easier to do this with GPT and plain partitions; and with Btrfs it's easy and efficient in that  you can still have LV-like subvolumes but you don't have to deal with individually shrinking them.
>
> For LVM the gist is you:
>
> 1. shrink a file system on an LV
> 2. shrink the LV
> 3. pvmove to move extents from the end of the LVM partition so that free extents are at the end
> 4. pvresize to shink the PV
> 5. vgreduce to account for the shrunk PV
> 6. fdisk/parted to change the PV partition size and create a new partition
>
> system-storage-manager might be able to do some or all of those steps for you with a single command, but I haven't tried it.
>
>
> Chris Murphy

I am leaning toward putting it off for a while to harvest as much as I 
can from the F-19 install [there always seems to be something I've 
missed] and then just start over with a new install. I would at least 
like to see the rescue disk stuff work though.

Thanks for your response,

Bob

-- 
http://www.qrz.com/db/w2bod
Box10 Fedora-20/64bit Linux/XFCE