# LVM - Add new disk and extend FS

### Rescan for newly added disks without rebooting:

The command will iterate over all found host adapters and trigger a rescan.
```
>> for host in /sys/class/scsi_host/*; do echo "- - -" | sudo tee $host/scan; ls /dev/sd* ; done
- - -
/dev/sda  /dev/sda1  /dev/sda2  /dev/sdb  /dev/sdb1  /dev/sdb2  /dev/sdc  /dev/sdc1
- - -
/dev/sda  /dev/sda1  /dev/sda2  /dev/sdb  /dev/sdb1  /dev/sdb2  /dev/sdc  /dev/sdc1
- - -
/dev/sda  /dev/sda1  /dev/sda2  /dev/sdb  /dev/sdb1  /dev/sdb2  /dev/sdc  /dev/sdc1  /dev/sdd
- - -
/dev/sda  /dev/sda1  /dev/sda2  /dev/sdb  /dev/sdb1  /dev/sdb2  /dev/sdc  /dev/sdc1  /dev/sdd  /dev/sdd1
```
The output shows when a new drive has been discovered.

### LVM add "physical" disk and extend FS

* Make sure there is a Partition Table and a Partition for LVM  
```
fdisk /dev/<disk>
>> create new gpt table: g
>> create new partition: n
>> set type of partition to lvm: t 
>> show partition codes: L
>> insert type: <type from L (Linux LVM)>
>> write changes: w
```
* Expand existing LVM VG
```sh
pvcreate /dev/<disk-partition>
vgextend <existing-vg> /dev/<disk-partition>
```

* Expand existing LVM LV
```sh
# find the correct logical volume
lvdisplay | grep Path 

# expand found lv
lvresize -l +100%free <lv path>
```

* Expand the ext4 filesystem on it
```sh
resize2fs <lv path>
```

#### Sources:
* Add disk: [https://tylersguides.com/guides/how-to-add-a-disk-to-lvm/]()
* Extend FS: [https://www.systutorials.com/extending-a-mounted-ext4-file-system-on-lvm-in-linux/]()