LVM: Extend an existing Logical Volume / Filesystem

LVM: Extend an existing Logical Volume / Filesystem

# Tested on RHEL 5, 6 & 7


# Concatenated volume
# ------------------------------------------------------------------------------------------

MNTPT=/testmntpt
SIZE=500                  # Size to add in Mbytes

VG=`mount | awk '{if ( $3 == "'$MNTPT'" ) print$1}' | cut -f4 -d'/' | cut -f1 -d '-'`
LV=`mount | awk '{if ( $3 == "'$MNTPT'" ) print$1}' | cut -f4 -d'/' | cut -f2 -d '-'`


df -h $MNTPT
   Filesystem            Size  Used Avail Use% Mounted on
   /dev/mapper/testvg-testlv
                         485M   11M  449M   3% /testmntpt
lvs | grep $LV
   testlv   testvg -wi-ao--- 500.00m



# First, verify if there is enough free space in the VG

vgdisplay $VG | grep Free
   Free  PE / Size       391 / 1.53 GiB


# Then, extend LV. Here size is given in Mbytes. To specify size in Logical Extents use '-l'

lvextend -L +$SIZE  /dev/$VG/$LV

# ** Size to be added to volume may be specified as a percentage of remaining free space of
# the volume group like this (in this case we take all available free space):
#
# lvextend -l +100%FREE -n /dev/$VG/$LV



lvs | grep $LV
   testlv   testvg -wi-ao--- 1012.00m


# Finally, extend filesystem

# For ext2/ext3 on RHEL 5 and ext2/ext3/ext4 on RHEL 6 & RHEL 7:

resize2fs -p /dev/$VG/$LV
   resize2fs 1.41.12 (17-May-2010)
   Filesystem at /dev/testvg/testlv is mounted on /testmntpt; on-line resizing required
   old desc_blocks = 2, new_desc_blocks = 4
   Performing an on-line resize of /dev/testvg/testlv to 1036288 (1k) blocks.
   The filesystem on /dev/testvg/testlv is now 1036288 blocks long.

# *** For ext4 F.S. on RHEL 5:
# resize4fs -p /dev/$VG/$LV

# *** For xfs F.S.:
# xfs_growfs -d /dev/$VG/$LV


df -h $MNTPT
   Filesystem            Size  Used Avail Use% Mounted on
   /dev/mapper/testvg-testlv
                         981M   11M  920M   2% /testmntpt



# Striped volume
# ------------------------------------------------------------------------------------------

MNTPT=/testmntpt
SIZE=256                  # Size to add in Mbytes

VG=`mount | awk '{if ( $3 == "'$MNTPT'" ) print$1}' | cut -f4 -d'/' | cut -f1 -d '-'`
LV=`mount | awk '{if ( $3 == "'$MNTPT'" ) print$1}' | cut -f4 -d'/' | cut -f2 -d '-'`



df -h $MNTPT
   Filesystem            Size  Used Avail Use% Mounted on
   /dev/mapper/testvg-testlv
                         504M   17M  462M   4% /testmntpt
lvs | grep $LV
   testlv   testvg -wi-ao--- 512.00m


# First, verify free space on volume group and disks

vgdisplay -v $VG
   [...]
   Free  PE / Size       388 / 1.52 GiB

   [...]
   --- Physical volumes ---
   PV Name               /dev/sde1                                   <--- Used
   PV UUID               DFfnXR-fjK3-V5Tz-oFHM-Py1T-rW4G-2DUz4f
   PV Status             allocatable
   Total PE / Free PE    129 / 65

   PV Name               /dev/sde2                                   <--- Used
   PV UUID               nQ3O7h-N8wH-FN9v-jmXu-5j5c-KZ25-IMUmGt
   PV Status             allocatable
   Total PE / Free PE    129 / 65

   PV Name               /dev/sde3
   PV UUID               CT1trl-90zb-afrY-bCAM-0Xas-3Shs-hLCw2m
   PV Status             allocatable
   Total PE / Free PE    129 / 129

   PV Name               /dev/sde4
   PV UUID               anN3BB-pafi-0ZE9-lpOw-Q0iL-EPiF-EQTUT0
   PV Status             allocatable
   Total PE / Free PE    129 / 129


# Then, extend LV. Here size is given in Mbytes. To specify size in Logical Extents use '-l'

# We'll try to keep the distribution regarding striping over disks. In this case I'm adding
# 256M and there is enough space on disks in use so it is not necessary to specify disks as
# LVM will be able to allocate extents directly on them:

lvextend -L +$SIZE  /dev/$VG/$LV
   Extending logical volume testlv to 768.00 MiB
   Logical volume testlv successfully resized

# Let's check what we did:

vgdisplay -v $VG | egrep "VG Name|Free|PV Name"
   VG Name               testvg
   Free  PE / Size       324 / 1.27 GiB
   VG Name                testvg
   PV Name               /dev/sde1     <--- Used
   Total PE / Free PE    129 / 33
   PV Name               /dev/sde2     <--- Used
   Total PE / Free PE    129 / 33
   PV Name               /dev/sde3
   Total PE / Free PE    129 / 129
   PV Name               /dev/sde4
   Total PE / Free PE    129 / 129

# Otherwise, if we want to add extents on specific disks, we may do it (Let's add 256
# additional MiB):

SIZE=256
DISKS="/dev/sde3 /dev/sde4"

lvextend -L +$SIZE  /dev/$VG/$LV $DISKS
   Extending logical volume testlv to 1.00 GiB
   Logical volume testlv successfully resized

vgdisplay -v $VG | egrep "VG Name|Free|PV Name"
   VG Name               testvg
   Free  PE / Size       260 / 1.02 GiB
   VG Name                testvg
   PV Name               /dev/sde1
   Total PE / Free PE    129 / 33
   PV Name               /dev/sde2
   Total PE / Free PE    129 / 33
   PV Name               /dev/sde3     <--- Used
   Total PE / Free PE    129 / 97
   PV Name               /dev/sde4     <--- Used
   Total PE / Free PE    129 / 97

# If we don't indicate disks, system will try to allocate extents on disks that were used
# during the last 'extend' operation:

SIZE=256

lvextend -L +$SIZE  /dev/$VG/$LV
   Extending logical volume testlv to 1.25 GiB
   Logical volume testlv successfully resized

vgdisplay -v $VG | egrep "VG Name|Free|PV Name"
   VG Name               testvg
   Free  PE / Size       196 / 784.00 MiB
   VG Name                testvg
   PV Name               /dev/sde1
   Total PE / Free PE    129 / 33
   PV Name               /dev/sde2
   Total PE / Free PE    129 / 33
   PV Name               /dev/sde3     <--- Used
   Total PE / Free PE    129 / 65
   PV Name               /dev/sde4     <--- Used
   Total PE / Free PE    129 / 65


# Finally, if there is no enough free space on disks that were used last, system will first
# fill them up and then will allocate extents on the other disks

SIZE=725

lvextend -L +$SIZE  /dev/$VG/$LV
   Extending logical volume testlv to 1.96 GiB
   Logical volume testlv successfully resized

vgdisplay -v $VG | egrep "VG Name|Free|PV Name"
   VG Name               testvg
   Free  PE / Size       14 / 56.00 MiB
   VG Name                testvg
   PV Name               /dev/sde1     <--- Used step 2
   Total PE / Free PE    129 / 7
   PV Name               /dev/sde2     <--- Used step 2
   Total PE / Free PE    129 / 7
   PV Name               /dev/sde3     <--- Used step 1
   Total PE / Free PE    129 / 0
   PV Name               /dev/sde4     <--- Used step 1
   Total PE / Free PE    129 / 0



# Let's see extent distribution:

lvdisplay -m $VG/$LV
   [...]
   --- Segments ---
   Logical extent 0 to 191:
     Type                striped
     Stripes             2
     Stripe size         64.00 KiB
     Stripe 0:
       Physical volume   /dev/sde1     <--- 1st extension
       Physical extents  0 to 95
     Stripe 1:
       Physical volume   /dev/sde2     <--- 1st extension
       Physical extents  0 to 95

   Logical extent 192 to 449:
     Type                striped
     Stripes             2
     Stripe size         64.00 KiB
     Stripe 0:
       Physical volume   /dev/sde3     <--- 2nd and 3rd extensions
       Physical extents  0 to 128
     Stripe 1:
       Physical volume   /dev/sde4     <--- 2nd and 3rd extensions
       Physical extents  0 to 128

   Logical extent 450 to 501:
     Type                striped
     Stripes             2
     Stripe size         64.00 KiB
     Stripe 0:
       Physical volume   /dev/sde1     <--- 4th extension
       Physical extents  96 to 121
     Stripe 1:
       Physical volume   /dev/sde2     <--- 4th extension
       Physical extents  96 to 121


# Anyway, try to maintain a "logical" distribution when extending a striped volume


lvs | grep $LV
   testlv   testvg -wi-a---- 1.96g


# Finally, extend filesystem

# For ext2/ext3 on RHEL 5 and ext2/ext3/ext4 on RHEL 6 & RHEL 7:

resize2fs -p /dev/$VG/$LV
   resize2fs 1.42.9 (28-Dec-2013)
   Filesystem at /dev/testvg/testlv is mounted on /testmntpt; on-line resizing required
   old_desc_blocks = 1, new_desc_blocks = 1
   The filesystem on /dev/testvg/testlv is now 514048 blocks long.

# *** For ext4 F.S. on RHEL 5:
# resize4fs -p /dev/$VG/$LV

# *** For xfs F.S.:
# xfs_growfs -d /dev/$VG/$LV

df -h $MNTPT
   Filesystem                 Size  Used Avail Use% Mounted on
   /dev/mapper/testvg-testlv  2.0G  788K  1.9G   1% /testmntpt



# Mirrored volume
# ------------------------------------------------------------------------------------------

MNTPT=/testmntpt
SIZE=128                  # Size to add in Mbytes

VG=`mount | awk '{if ( $3 == "'$MNTPT'" ) print$1}' | cut -f4 -d'/' | cut -f1 -d '-'`
LV=`mount | awk '{if ( $3 == "'$MNTPT'" ) print$1}' | cut -f4 -d'/' | cut -f2 -d '-'`



df -h $MNTPT
   Filesystem            Size  Used Avail Use% Mounted on
   /dev/mapper/testvg-testlv
                         248M   11M  226M   5% /testmntpt
lvs | grep $LV
   testlv   testvg mwi-aom-- 256.00m                         testlv_mlog   100.00


# First, verify free space on volume group and disks

vgdisplay -v $VG
   [...]
   Free  PE / Size       387 / 1.51 GiB

   [...]
   --- Physical volumes ---
   PV Name               /dev/sde1                                   <--- Used
   PV UUID               DFfnXR-fjK3-V5Tz-oFHM-Py1T-rW4G-2DUz4f
   PV Status             allocatable
   Total PE / Free PE    129 / 65

   PV Name               /dev/sde2                                   <--- Used
   PV UUID               nQ3O7h-N8wH-FN9v-jmXu-5j5c-KZ25-IMUmGt
   PV Status             allocatable
   Total PE / Free PE    129 / 64

   PV Name               /dev/sde3
   PV UUID               CT1trl-90zb-afrY-bCAM-0Xas-3Shs-hLCw2m
   PV Status             allocatable
   Total PE / Free PE    129 / 129

   PV Name               /dev/sde4
   PV UUID               anN3BB-pafi-0ZE9-lpOw-Q0iL-EPiF-EQTUT0
   PV Status             allocatable
   Total PE / Free PE    129 / 129


# Then, extend LV. Here size is given in Mbytes. To specify size in Logical Extents use '-l'

# We'll try to keep the distribution regarding mirroring over disks. In this case I'm adding
# 128M and there is enough space on disks in use so it is not necessary to specify disks as
# LVM will be able to allocate extents directly on them:

lvextend -L +$SIZE  /dev/$VG/$LV
   Extending 2 mirror images.
   Extending logical volume testlv to 384.00 MiB
   Logical volume testlv successfully resized

# Let's check what we did:

vgdisplay -v $VG | egrep "VG Name|Free|PV Name"
   VG Name               testvg
   Free  PE / Size       323 / 1.26 GiB
   VG Name                testvg
   PV Name               /dev/sde1     <--- Used
   Total PE / Free PE    129 / 33
   PV Name               /dev/sde2     <--- Used
   Total PE / Free PE    129 / 32
   PV Name               /dev/sde3
   Total PE / Free PE    129 / 129
   PV Name               /dev/sde4
   Total PE / Free PE    129 / 129

# Otherwise, if we want to add extents on specific disks, we may do it (Let's add 256
# additional MiB):

SIZE=256
DISKS="/dev/sde3 /dev/sde4"

lvextend -L +$SIZE  /dev/$VG/$LV $DISKS
   Extending 2 mirror images.
   Extending logical volume testlv to 640.00 MiB
   Logical volume testlv successfully resized

vgdisplay -v $VG | egrep "VG Name|Free|PV Name"
   VG Name               testvg
   Free  PE / Size       195 / 780.00 MiB
   VG Name                testvg
   PV Name               /dev/sde1
   Total PE / Free PE    129 / 33
   PV Name               /dev/sde2
   Total PE / Free PE    129 / 32
   PV Name               /dev/sde3     <--- Used
   Total PE / Free PE    129 / 65
   PV Name               /dev/sde4     <--- Used
   Total PE / Free PE    129 / 65


# If we don't indicate disks, system will try to allocate extents on disks that were used
# during the last 'extend' operation:


SIZE=250

lvextend -L +$SIZE  /dev/$VG/$LV
   Extending 2 mirror images.
   Extending logical volume testlv to 892.00 MiB
   Logical volume testlv successfully resized

vgdisplay -v $VG | egrep "VG Name|Free|PV Name"
   VG Name               testvg
   Free  PE / Size       69 / 276.00 MiB
   VG Name                testvg
   PV Name               /dev/sde1
   Total PE / Free PE    129 / 33
   PV Name               /dev/sde2
   Total PE / Free PE    129 / 32
   PV Name               /dev/sde3     <--- Used
   Total PE / Free PE    129 / 2
   PV Name               /dev/sde4     <--- Used
   Total PE / Free PE    129 / 2


# Finally, if there is no enough free space on disks that were used last, system will first
# fill them up and then will allocate extents on the other disks

SIZE=128

lvextend -L +$SIZE  /dev/$VG/$LV
   Extending 2 mirror images.
   Extending logical volume testlv to 1020.00 MiB
   Logical volume testlv successfully resized

vgdisplay -v $VG | egrep "VG Name|Free|PV Name"
  VG Name               testvg
  Free  PE / Size       5 / 20.00 MiB
  VG Name                testvg
  PV Name               /dev/sde1     <--- Used step 2
  Total PE / Free PE    129 / 3
  PV Name               /dev/sde2     <--- Used step 3
  Total PE / Free PE    129 / 2
  PV Name               /dev/sde3     <--- Used step 1
  Total PE / Free PE    129 / 0
  PV Name               /dev/sde4     <--- Used step 1
  Total PE / Free PE    129 / 0



# Anyway, try to maintain a "logical" distribution when extending a mirrored volume


lvs | grep $LV
   testlv   testvg mwi-aom-- 1020.00m                         testlv_mlog   100.00


# Finally, extend filesystem

# For ext2/ext3 on RHEL 5 and ext2/ext3/ext4 on RHEL 6 & RHEL 7:

resize2fs -p /dev/$VG/$LV
   resize2fs 1.41.12 (17-May-2010)
   Filesystem at /dev/testvg/testlv is mounted on /testmntpt; on-line resizing required
   old desc_blocks = 1, new_desc_blocks = 4
   Performing an on-line resize of /dev/testvg/testlv to 1044480 (1k) blocks.
   The filesystem on /dev/testvg/testlv is now 1044480 blocks long.

# *** For ext4 F.S. on RHEL 5:
# resize4fs -p /dev/$VG/$LV

# *** For xfs F.S.:
# xfs_growfs -d /dev/$VG/$LV


df -h $MNTPT
   Filesystem            Size  Used Avail Use% Mounted on
   /dev/mapper/testvg-testlv
                         988M   11M  926M   2% /testmntpt
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