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--- linux:lvm [2006/06/09 00:15]
a created
+++ linux:lvm [2009/05/25 00:35] (current)
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-====== LVM ======
+====== 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]]
+  * [[http://www.howtoforge.com/encrypted-root-lvm|Encrypted root LVM]]
+===== 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
+===== Resizing crypted LVM  =====
+   cryptsetup -c aes -h ripemd160 -s 256 create home /dev/disk_array/data
+   pvcreate /dev/hde1
+   vgextend disk_array /dev/hde1
+   lvresize -L +114G /dev/disk_array/data
+   cryptsetup resize home
+   resize_reiserfs -s +114G /dev/mapper/home