LVM - Revision history

Kenneth: /* update systemd */

2026-04-01T19:16:56Z

update systemd

← Older revision		Revision as of 19:16, 1 April 2026
Line 160:		Line 160:
	systemd will complain:		systemd will complain:
	<pre>		<pre>
			# mount /data
	mount: (hint) your fstab has been modified, but systemd still uses		mount: (hint) your fstab has been modified, but systemd still uses
	the old version; use 'systemctl daemon-reload' to reload.		the old version; use 'systemctl daemon-reload' to reload.

Kenneth: /* Mounting LVM Logical Volume */

2026-04-01T19:16:35Z

Mounting LVM Logical Volume

@@ Line 130: / Line 130: @@
 To deactivate a volume group:
   vgchange -an <volume group>
 ==Mounting LVM Logical Volume==
@@ Line 147: / Line 153: @@
 # data volume added after system install
 /dev/mapper/vg_data-lv_data     /data           xfs     defaults        0 0
 </pre>
 ==Extend an LVM partition==

Kenneth: /* fstab */

2026-04-01T19:11:46Z

fstab

← Older revision		Revision as of 19:11, 1 April 2026
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	/dev/mapper/rhel-swap none swap defaults 0 0		/dev/mapper/rhel-swap none swap defaults 0 0

			# data volume added after system install
	/dev/mapper/vg_data-lv_data /data xfs defaults 0 0		/dev/mapper/vg_data-lv_data /data xfs defaults 0 0
	</pre>		</pre>

Kenneth: /* Mounting LVM Logical Volume */

2026-04-01T19:11:27Z

Mounting LVM Logical Volume

@@ Line 137: / Line 137: @@
 Mount LVM device:
   mount /dev/[VG]/[LV] /data
 ==Extend an LVM partition==

Kenneth: /* Logical Volumes */

2026-04-01T19:10:38Z

Logical Volumes

← Older revision		Revision as of 19:10, 1 April 2026
Line 93:		Line 93:
	Display Logical Volumes:		Display Logical Volumes:
	lvdisplay		lvdisplay
	lvdisplay <~~logical volume name~~>
			# lvdisplay <vg_name> -- show all LVs under a VG
			lvdisplay rhel # show all rhel lvs (/dev/rhel/var, /dev/rhel/root, /dev/rhel/swap)
			lvdisplay vg_data

			# lvdisplay <vg_name/lv_name> -- show specific LV
			lvdisplay rhel/root
			lvdisplay vg_data/lv_data

	"Ok, you've created a blank receptacle but now you have to tell how many Physical Extents from the physical device (/dev/md0 in this case) will be allocated to this Volume Group. In my case I wanted all the data from /dev/md0 to be allocated to this Volume Group. If later I wanted to add additional space I would create a new RAID array and add that physical device to this Volume Group.		"Ok, you've created a blank receptacle but now you have to tell how many Physical Extents from the physical device (/dev/md0 in this case) will be allocated to this Volume Group. In my case I wanted all the data from /dev/md0 to be allocated to this Volume Group. If later I wanted to add additional space I would create a new RAID array and add that physical device to this Volume Group.

Kenneth: /* Logical Volumes */

2026-04-01T19:06:45Z

Logical Volumes

← Older revision		Revision as of 19:06, 1 April 2026
Line 110:		Line 110:
	lvcreate -l <PEs> <volume group name> -n <logical volume name>		lvcreate -l <PEs> <volume group name> -n <logical volume name>
	lvcreate -l 57235 lvm-raid -n lvm0		lvcreate -l 57235 lvm-raid -n lvm0

			# lvcreate -l 100%FREE -n <LV Name> <VG Group>
			lvcreate -l 100%FREE -n lv_data vg_data

	Remove logical volume:		Remove logical volume:
	lvremove <logical volume name>		# lvremove <logical volume name>
			lvremove vg_data/lv_data

	If a volume group shows inactive, you can activate it with:		If a volume group shows inactive, you can activate it with:

Kenneth: /* Volume Groups */

2026-04-01T18:56:39Z

Volume Groups

← Older revision		Revision as of 18:56, 1 April 2026
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	# vgdisplay <volume group name>		# vgdisplay <volume group name>
	vgdisplay mydata		vgdisplay mydata
			vgdisplay vg_data

	Show Volume Groups with Physical Volumes:		Show Volume Groups with Physical Volumes:
Line 75:		Line 76:
	vgcreate lvm-raid /dev/md0		vgcreate lvm-raid /dev/md0
	vgcreate lvm-hde /dev/hdf1 /dev/hde5		vgcreate lvm-hde /dev/hdf1 /dev/hde5

	vgcreate vg_data /dev/sdb		vgcreate vg_data /dev/sdb

Kenneth: /* Volume Groups */

2026-04-01T18:55:57Z

Volume Groups

← Older revision		Revision as of 18:55, 1 April 2026
Line 61:		Line 61:
	Display Volume Groups:		Display Volume Groups:
	vgdisplay		vgdisplay
	vgdisplay <volume group name>
			# vgdisplay <volume group name>
			vgdisplay mydata

	Show Volume Groups with Physical Volumes:		Show Volume Groups with Physical Volumes:
Line 73:		Line 75:
	vgcreate lvm-raid /dev/md0		vgcreate lvm-raid /dev/md0
	vgcreate lvm-hde /dev/hdf1 /dev/hde5		vgcreate lvm-hde /dev/hdf1 /dev/hde5

			vgcreate vg_data /dev/sdb

	"The default value for the physical extent size can be too low for a large RAID array. In those cases you'll need to specify the -s option with a larger than default physical extent size. The default is only 4MB as of the version in Fedora Core 5. The maximum number of physical extents is approximately 65k so take your maximum volume size and divide it by 65k then round it to the next nice round number. For example, to successfully create a 550G RAID let's figure that's approximately 550,000 megabytes and divide by 65,000 which gives you roughly 8.46. Round it up to the next nice round number and use 16M (for 16 megabytes) as the physical extent size and you'll be fine:" [http://www.gagme.com/greg/linux/raid-lvm.php]		"The default value for the physical extent size can be too low for a large RAID array. In those cases you'll need to specify the -s option with a larger than default physical extent size. The default is only 4MB as of the version in Fedora Core 5. The maximum number of physical extents is approximately 65k so take your maximum volume size and divide it by 65k then round it to the next nice round number. For example, to successfully create a 550G RAID let's figure that's approximately 550,000 megabytes and divide by 65,000 which gives you roughly 8.46. Round it up to the next nice round number and use 16M (for 16 megabytes) as the physical extent size and you'll be fine:" [http://www.gagme.com/greg/linux/raid-lvm.php]

Kenneth: /* Physical Volumes */

2026-04-01T18:53:34Z

Physical Volumes

← Older revision		Revision as of 18:53, 1 April 2026
Line 35:		Line 35:
	Display Physical Volumes:		Display Physical Volumes:
	pvdisplay		pvdisplay
	pvdisplay <device>
			# pvdisplay <device>
			pvdisplay /dev/sdb

	Initialize a disk or parition for use by LVM:		Initialize a disk or parition for use by LVM:

Kenneth: /* Physical Volumes */

2026-04-01T17:51:11Z

Physical Volumes

← Older revision		Revision as of 17:51, 1 April 2026
Line 48:		Line 48:
	# Fix Error: "Device /dev/sdb excluded by a filter"		# Fix Error: "Device /dev/sdb excluded by a filter"
	wipefs -a /dev/sdb		wipefs -a /dev/sdb

			# if you need to get aggressive about it and force it:
			wipefs -af /dev/sdb

	===Volume Groups===		===Volume Groups===