DataIQ 2.2 Admin Guide

Add a new drive to a volume (LVM)

If a volume group created using a logical volume manager (LVM) is running out of space, you can expand it by adding a new drive to the volume group, then expanding the existing volume group partition onto the new drive.

1. Log into the DataIQ server and open a command prompt.
2. Optional: Confirm that the size of the logical volume and note how full it is:

   df -h /

   Sample output:

   [root@centos76 ~]# df -h /
   Filesystem                Size    Used    Avail    Use%   Mounted on
   /dev/mapper/centos-root    26G     22G       4G     85%            /

3. Add a physical drive to the server.
   Linux adds the drive using a disk name, for example, /dev/sdb.
4. Identify the disk name for the drive you just added.

   fdisk -l

   In this sample output, the disk name is /dev/sdb:

   # fdisk -l
   Disk /dev/sda: 32.2 GB, 32212254720 bytes, 62914560 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: 0x000bde50
   
      Device Boot     Start       End    Blocks   Id   System
   /dev/sdal   *       2048   2099199   1048576   83   Linux
   /dev/sda2        2099200  62914559  30407680   8e   Linux LVM
   
   Disk /dev/mapper/centos-root : 27.9 GB, 27913093120 bytes, 54517760 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 /dev/mapper/centos-swap: 3221 MB, 3221225472 bytes, 6291456 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 /dev/sdb: 53.7 GB, 53687091200 bytes, 104857600 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

   (Also note in this example, /dev/sda2 is the primary Linux LVM physical volume in the volume group.)

5. Create a new partition on the new drive and configure it:
   1. Open the fdisk console, targeting the new drive:

      fdisk /dev/sdb

   2. Create a new primary partition, using the default partition values: n > p> press Enter 3 times to accept the defaults (partition = 1, use all available space on the drive).
   3. Change the partition type to Linux LVM: type t > 8e.
   4. Review the partition info that will be written: type p.

      Sample output:

      Disk /dev/sdb: 53.7 GB, 53687091200 bytes, 104857600 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: 0xa883580d
      
           Device Boot     Start         End     Blocks    Id   System
      /dev/sdbl             2048   104857599   52427776    8e   Linux LVM

   5. Write the partition table and exit: type w.

      Sample output:

      The partition table has been altered!
      
      Calling ioctl() to re-read partition table. 
      Syncing disks.

6. Create a new physical volume on the new partition, for example, /dev/sdb1.

   pvcreate /dev/sdb1

7. Confirm that the physical volume has been created:

   pvdisplay

   In the sample output, the original physical volume, /dev/sda2, and the new physical volume, /dev/sdb1, are shown:

   [root@centos ~]# pvdisplay
     --- Physical volume ---
     PV Name             /dev/sda2
     VG Name             centos
     PV Size             <23.80 GiB / not usable 3.00 MiB
     Allocatable         yes (but full)
     PE Size             4.00 MiB
     Total PE            7423
     Free PE             0
     Allocated PE        7423
     PV UUID             4g3yVT-3i7e-s xgH-EOGx-aykB-83xs-JxLCj6
   
     "/dev/sdbl" is a new physical volume of "<50.00 GiB" 
     --- NEW Physical volume ---
     PV Name             /dev/sdbl
     VG Name             <50.00 GiB
     PV Size             NO
     Allocatable         0
     PE Size             0
     Total PE            0
     Free PE             0
     Allocated PE        0
     PV UUID             qa7tv0-ryIa-kTec-E81o-RSxa-HpLz-wlPHOk

8. Identify the volume group name (VG Name) of the volume group that you want to expand:

   vgdisplay

   For example, in this output, the only volume group is centos:

   [ root@centos76 -]# vgdisplay
   
     - Volume group —
     VG Name               centos
     System ID
     Format                Lvmz
     Metadata Areas        1
     Metadata Sequence No  3
     VG Access             read/write
     VG Status             resizable
     MAX LV                0
     Cur LV                2
     Open LV               2
     Max PV                0
     Cur PV                1
     Act PV                1
     VG Size               <29.00 GiB
     PE Size               4.00 MiB
     Total PE              7423
     Alloc PE / Size       7423 / <29.00 GiB
     Free PE / Size        0/0
     VG UUID               omT41C-L5Oq-393P-LxHN-XO6q-0oi8-2blglP

9. Add the physical volume which we created earlier to the volume group:

   vgextend centos /dev/sdb1

10. Confirm the logical volume path (LV Path)

    lvdisplay

    In this sample output, the logical volume path is /dev/centos/root.

    LV Path        /dev/centos/swap
    LV Name                 swap
    VG Name                 centos
    LV UUID                 wC9BlK-qeG5-tj2f-oQtN-AKTP-xfGA-fxk4JT 
    LV Write Access         read/write
    LV Creation host, time  sarje-dpcwin2kl2r2.dpc.sso, 2019-07-02 05:43:34 -0400
    LV Status               available 
    # open                  2
    LV Size                 3.00 GiB
    Current LE              768
    Segments                1
    Allocation              inherit
    Read ahead sectors      auto
    - currently set to      8192
    Block device            253:1
    
    --- Logical volume --- 
    LV Path                 /dev/centos/root
    LV Name                 root
    VG Name                 centos
    LV UUID                 XKVxr8-GFfq-XoKa-ytkb-Mloe-nVig-0j01mf
    LV Write Access         read/write
    LV Creation host, time  sarje-dpcwin2kl2r2.dpc.sso, 2019-07-02 05:43:35 -0400 
    LV Status               available 
    # open                  1
    LV Size                 <26.00 GiB 
    Current LE              6655 
    Segments                1
    Allocation              inherit
    Read ahead sectors      auto
    - currently set to      8192
    Block device            253:0

11. Extend the logical volume using the space in the newly-created physical volume:

    lvextend /dev/centos/root /dev/sdb1

12. Resize the file system to make use of the space:

    xfs_growfs /dev/centos/root

13. Confirm that the size of the logical volume has changed:

    df -h /

    Sample output:

    [root@centos76 ~]# df -h /
    Filesystem                   Size    Used    Avail    Use%   Mounted on
    /dev/mapper/centos-root       76G     22G      54G     29%            /