Resizing a live logical volume
If you use lvm to abstract the filesystems away from the direct hardware, you might need to know how to add additional space without taking the filesystem offline. This post shows how you might do that.
Attach new disk
Save current state to a file for comparison.
ls -l /dev/{s,v}d* > ~/ls.dev.sd.before
Install additional disk to system (in hypervisor or attach to physical machine).
Scan with rescan-scsi-bus.sh (from sg3_utils package).
If that fails, try
find /sys/class/scsi_host/host*/scan | while read line; do echo "- - -" > $line; done
lsblk
Find the name of the new disk:
ls -l /dev/{s,v}d* > ~/ls.dev.sd.after
diff ~/ls.dev.sd.before ~/ls.dev.sd.after
The output should be the name of the new disk.
Create a new partition
How to do it in fdisk:
fdisk /dev/newdisk
n[enter]
p[enter]
1[enter]
[enter]
w[enter]
Add the partition to lvm and the logical volume
pvcreate /dev/newdisk1
vgextend vgname /dev/newdisk1
lvextend /dev/vgname/lvname /dev/newdisk1
Resize the filesystem
Filesystem type ext4 can be resized live:
resize2fs /dev/vgname/lvname