LVM Presenttation

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About LVM (LOGICAL VOLUME MANAGER)

• Powered by md Maksudur Rahman
• Id-1178314
• Batch -24 -acsl (IDB-BISEW Diploma in Networking
  Technologies)

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Overvew

• What is LVM
• Why we use LVM
• When Should You Use LVM
• Body , parts and soul
• How to use LVM on linux
• LVM configuration
• Common command LVM
• Known issue
• LVM resources

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What is LVM

•  Logical Volume Manager (LVM) is a device mapper
  target that provides a more flexible way to
  manage disk space than physical disk partition
• Logical Volume Management (LVM) is a disk
  management option
•  Present the higher level the disk storage
• Provides flexibility in allocating storage
• Easy Maintenance
• To manage user-define logical group
• LVM2 Is similar to LVM

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Why we use LVM

• Some of your partition filled up you want to
  expand it
• You want to shirnk your partition
• Add one or more disk/device
• You want to take backup of your file
  system/partition while you are still using it

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Body parts and soul

• Phyiscal Volume(PV Create)
• Volume Group(VG Create)
• Logical Volume(LV Create)
• Physical Extent
• Logical Extent
• Device Mapper
• Snapshot

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How to use LVM on linux

• CREATING A NEW LOGICAL VOLUME
• Create a Physical volume (one
  or more partititon or whole disk)
• Create a volume group
  (one or more physical volume)
• Create a logical
  volume (using volume group)
• EXPANDING A LOGICAL VOLUME (logical volume out of
  space)
• Create a physical volume
• Add it to the Volume group(in case
  vg does not have enough space
• expand the logical volume

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LVM configuration

• Frist we need to create Physical volume like
  this
• pvcreate /dev/sda /dev/sdb
  ,,,here sdasdb hard disk)
• see physical volume pvdisplay
• Now create volime group VG
• vgcreate vg1 /dev/sda /dev/sdb(here
  vg1 is my vg name)
• to see vg1run this command
  vgdisplay
• Now create lv(logical volume)to use vg1
• lvcreate n lv1 L 2G vg1(here
  lv1 is my lv name space 2GB )see lvdisplay
• Now create a file system for lv1 -- mkfs.ext4
  /dev/vg1/lv1
• last go to vim /etc/fstab mount it

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LVM CONFIGURATION

• EXTEND A LOGICAL VOLUME
• Create a physical volume pvcreate
  /dev/sdc
• now extend your vg vgextend vg1
  /dev/sdc here sdc extra hard disk
• EXTEND LV (umount is task)
• lvextend L 1g /dev/vg1/lv1
• resize2fs p /dev/vg1/lv1
  (mount is a task)
• mount a mount -s

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LVM CONFIGURATION

• REDUCING LV
• lvreduce L 512M /Dev/vg1-lv1(here I
  want to reduce 512MB)
• I

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Common command LVM

• pvcreate pvdisplay pvremove
  pvmove pvscan
• vgcreate vgdisplay vgremove
  vgextend vgreduce vgextend vgscan
• lvcreate lvdisplay lvremove
  lvextend lvreduce lvresize
• lvmove lvmdiskscan

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Known issue

• Always read the release notes carefully for every
  relesase
• Snapshots are hard to use, slow and buggy
• Vulnerable to write caching due to hard drive/SSD
  or VM hypervisor
• you must take care in the filesystem, RAID, VM
  hypervisor, and hard drive/SSD setup used with LVM

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Thanks!!!

• Resources
• Red Hat System Administration ll
• www.redhat.com
• Searche engine google
• linux man page