is it possible to increase disk size by using/adding another clean disk

Question

we have the following disks from lsblk , all disks are not lvm

sdc                8:32   0    80G  0 disk /var/hadoop1
sdd                8:48   0    80G  0 disk /var/hadoop2
sde                8:64   0    80G  0 disk
sdf                8:80   0    80G  0 disk

sdc and sdd disks are full ( 100% used )

the status is that sdc and sdd disks are full and we can use them

but we have a new disks sde and sdf , each disk with size of 20G

so

is it possible to add the sde disk to sdc in order to give another 20G for sdc ?

Answer 1

Instead of adding disks on the level of operation system you can do this directly in hadoop. You can add them to the dfs.datanode.data.dir property. The format is

<property>
  <name>dfs.datanode.data.dir</name>
    <value>file:///disk/c0t2,/disk/c0t3,/dev/sde,/dev/sdf</value>
</property>

I am not 100% sure hadoop can handle RAW disks. In such case you can create on each new disk one big partition, format it, mount it /var/hadoop3, /var/hadoop4 and use format:

<property>
  <name>dfs.datanode.data.dir</name>
    <value>file:///disk/c0t2,/disk/c0t3,/var/hadoop3,/var/hadoop4</value>
</property>