Differences

This shows you the differences between two versions of the page.

--- linux:lvm [2006/10/29 15:03]
a LVM
+++ linux:lvm [2009/05/25 00:35]
@@ Line 1: / Line 1: @@
-====== Logical Volume Manager ======
-  * [[http://www.cyberciti.biz/tips/consistent-backup-linux-logical-volume-manager-snapshots.html|Consistent backup with Linux Logical Volume Manager (LVM) snapshots]]
-===== Example usage =====
-Start by looking at our existing disks
-	cat /proc/scsi/
-	dmesg |grep sd
-Next, partition the new disks using fdisk
-	fdisk /dev/sdb
-  * **p** to Print the existing table (should be blank)
-  * **n** to create a new partition
-  * **t** to change partition system ID to 8e (Linux LVM)
-  * **w** to write new table to disk
-Repeat for /dev/sdc
-Create the physical volumes
-	pvcreate /dev/sdb1
-	pvcreate /dev/sdc1
-//NOTE: You can create multiple PVs on a single disk, but it is not recommended. Show existing Physical Volumes//
-	pvscan
-Show Volume Groups
-	vgscan (should return nothing)
-Create a Volume Group from the Physical Volumes
-	vgcreate opt_vg /dev/sdb1 /dev/sdc1
-//NOTE: You can specify PE size in vgcreate. Default is 4M. You'd use larger PE sizes for LVs greater than 256G. 65K PEs per LV.//
-Show Volume Groups
-	vgscan (now shows the VG we created)
-Display information about the VG
-	vgdisplay
-Create a Logical Volume within the VG
-	lvcreate -l num_of_extents -n opt_lv opt_vg
-	lvcreate -L 100M -n opt_lv opt_vg
-	lvcreate -L 100M -n opt_lv -i num_stripes opt_vg
-	lvcreate -L 100M -n opt_lv opt_vg [PhysicalVolumePath]
-Display information about the LV
-	lvdisplay
-	lvdisplay -m (Show maps. Compare striped vs un-striped)
-Create a mount point
-	mkdir /opt/foo1
-	mkdir /opt/striped
-Create a filesystem
-	mkfs.ext3 /dev/opt_vg/opt_lv
-	mkfs.ext3 /dev/opt_vg/striped_lv
-Mount the filesystems
-	mount /dev/opt_vg/opt_lv
-	df -h
-===== Growing a Filesystem =====
-==== Grow an EXT2/3 filesystem (with unmount) ====
-Unmount the FS
-	umount /mnt/lvm_filesystem
-Extend the LV
-	lvresize -l +50 /dev/opt_vg/opt_lv
-	lvresize -L +200M /dev/opt_vg/opt_lv
-fsck the filesystem
-	e2fsck -f /dev/opt_vg/opt_lv
-Resize the filesystem
-	resize2fs /dev/opt_vg/opt_lv
-Remount the filesystem
-	mount -t ext3 /dev/opt_vg/opt_lv /mnt/lvm_filesystem
-==== Grow an EXT2/3 filesystem (without unmount) ====
-Extend the LV
-	lvresize -l +50 /dev/opt_vg/opt_lv
-	lvresize -L +200M /dev/opt_vg/opt_lv
-Grow the filesystem
-	ext2online /mnt/lvm_filesystem (using mount path)
-	ext2online /dev/opt_vg/opt_lv (using device)
-Grow a ReiserFS filesystem
-Create a ReiserFS on /dev/opt_vg/striped_lv
-	mkreiserfs /dev/opt_vg/striped_lv
-Mount the FS
-	df -h
-	lvresize -L +50M /dev/opt_vg/striped_lv
-	resize_reiserfs -f /dev/opt_vg/striped_lv
-	df -h
-Add a Physical Volume to a VG
-	vgextend vgname /path/to/PV