Mdthbs

I have a question regarding managing free or "unallocated" space in an LVM setup on CentOS.

What i need to do is make /var bigger, to accommodate some additional VM's that i am creating.

1. I would need to claim some of that free space << this is where I need the help
   


2. create the physical volume using pvcreate
   


3. extend the volume group using vgextend
   


4. extend the logical volume using lvextend
   


5. then grow the filesystem using xfs_grow
   

I have a 1TB disk in my server.
Of that 1TB disk, there is 721GB of unallocated space (see image attached)

These are the filesystems on the server:

Filesystem                            Size  Used Avail Use% Mounted on

/dev/mapper/scientific_physical-root   71G   17G   54G  25% /

devtmpfs                              9.7G     0  9.7G   0% /dev

tmpfs                                 9.8G  576K  9.8G   1% /dev/shm

tmpfs                                 9.8G  9.4M  9.8G   1% /run

tmpfs                                 9.8G     0  9.8G   0% /sys/fs/cgroup

/dev/mapper/scientific_physical-home  121G   12G  110G  10% /home

/dev/mapper/scientific_physical-var    63G   51G   13G  80% /var

/dev/sda1                             497M  215M  282M  44% /boot

tmpfs                                 2.0G   20K  2.0G   1% /run/user/1000

tmpfs                                 2.0G   24K  2.0G   1% /run/user/0

These are the LV's on the system:

  LV   VG                  Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert

  home scientific_physical -wi-ao---- 120.66g                                                    

  root scientific_physical -wi-ao----  70.30g                                                    

  swap scientific_physical -wi-ao----   2.93g                                                    

  var  scientific_physical -wi-ao----  63.00g 

These are the physical volumes:

  PV         VG                  Fmt  Attr PSize   PFree

  /dev/sda2  scientific_physical lvm2 a--  213.41g    0 

  /dev/sda3  scientific_physical lvm2 a--   46.56g 3.09g

This is my volume group:

  VG                  #PV #LV #SN Attr   VSize   VFree

  scientific_physical   2   4   0 wz--n- 259.98g 3.09g

[root@physical ~]# 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: 0x0004cb56



Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *        2048     1026047      512000   83  Linux

/dev/sda2         1026048   448595967   223784960   8e  Linux LVM

/dev/sda3       448598016   546254265    48828125   83  Linux

Edit #1:

here is the output from fdisk /dev/sda. I don't have a complete understanding of the Start /End /Blocks, but being that as it is, I still don't see the free space that should be available

[root@physical ~]# fdisk /dev/sda 

Welcome to fdisk (util-linux 2.23.2).



Changes will remain in memory only, until you decide to write them.

Be careful before using the write command.





Command (m for help): p



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: 0x0004cb56



   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *        2048     1026047      512000   83  Linux

/dev/sda2         1026048   448595967   223784960   8e  Linux LVM

/dev/sda3       448598016   546254265    48828125   83  Linux

Edit #2

OK so now I can see the space is there in parted! Wonderful and thank you!!
Now my question is, what would I have to do to actually grab some of this space to use it? I am assuming whatever I grab, in my exact scenario would now be called /dev/sda4. Would you be able to guide me on claiming 100GB from this free space?

Thanks so much!

[root@physical ~]# parted /dev/sda

(parted) print free                                                       

Model: ATA ST31000340NS (scsi)

Disk /dev/sda: 1000GB

Sector size (logical/physical): 512B/512B

Partition Table: msdos

Disk Flags: 



Number  Start   End     Size    Type     File system  Flags

        32.3kB  1049kB  1016kB           Free Space

 1      1049kB  525MB   524MB   primary  xfs          boot

 2      525MB   230GB   229GB   primary               lvm

        230GB   230GB   1049kB           Free Space

 3      230GB   280GB   50.0GB  primary

        280GB   1000GB  721GB            Free Space

There are a couple of ways to do this. You could resize partition 3, the run pvresize on /dev/sda3. The extend /dev/scientific_physical/var with lvresize with the -r option. That would grow the lvol and resize the fs all in one command. You could also create another partition. Then pvcreate /dev/sda4, vgextend scientific_physical with the new partition, then lvresize.

You could also see if there are actually any extents used on /dev/sda3. If not, do a vgreduce, then resize sda2, pvresize, lvresize. To do that you will need to reboot after the resize of sda2. A partprobe will complain that the disk is in use.