From 19b68bb3cd69e6e7d238bc3db5e764ea626a7686 Mon Sep 17 00:00:00 2001 From: Ibrahim Mkusa Date: Sun, 11 Aug 2024 20:05:54 -0400 Subject: [PATCH] using lvm tools to create and extend logical volumes aka lvm partitions --- partitions/managing_lvm.md | 39 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 partitions/managing_lvm.md diff --git a/partitions/managing_lvm.md b/partitions/managing_lvm.md new file mode 100644 index 0000000..fd7f6a7 --- /dev/null +++ b/partitions/managing_lvm.md @@ -0,0 +1,39 @@ +To work with lvm make sure lvm packages are installed on your system. If you +are adding an lvm partition manually follow the steps below. +Make sure there's enough unallocated space. Figure out the extent size, lets +say ==8M== chunks and we'll go for ==100== of these at least. Extents are the smallest +divisible units in a lvm file system. + +*** Create LVM volume group and a logical volume from a normal partition *** +``` +lsblk # identify device and partition +fdisk /dev/sda # '/dev/sda' is the device we'll be working with +# use n flag to create new partition +# use t flag to designate the new partition as 'lvm' +# use w to sync all changes to disk + +vgcreate -s 8M volume_name /dev/sda6 # -s specifies the extent size of 8M +lvcreate -n scratch -l 100 /dev/volume_name # -n for name, -l Num of Extents +mkfs.ext4 /dev/volume_name/scratch # formats the logical volume to ext4 +``` + +After volume is created, it needs to be mounted. You can simply create +a mountpoint `mkdir /scratch` or wherever, then edit ==/etc/fstab== to append +the volume likes so: +``` +/dev/volume_name/scratch /scratch ext4 defaults 0 0 + +``` + +If there any doubts, man vgcreate or man lvcreate are super helpful. The beauty +of lvm is its flexibility to resize beyond the restrictions of one or many +physical volumes +physical volumes -> volume group -> logical volumes + +We can use lvextend to add space to logical volume like so: +``` +lvextend -r -L +1G /dev/volume_name/scratch + +``` +==lvresize== adds more flexibility allowing you to shrink the volume. +