LVM procedure for HA systems

You can extend storage capacity of High Availability (HA) systems by using Logical Volume Manager (LVM) procedure on both primary and secondary hosts.

Before you begin

Warning:

Changing LVM configuration on a QRadar system might result in data loss and data corruption. Always take a full back up of the system before you start LVM procedure.
Extending storage on /store logical volume (LV) in a high availability pair triggers a full synchronization. This can take a significant amount of time depending on the size of /store and network configuration of the HA pair. High Availability feature is not available during the synchronization.
Ensure that High Availability pair is in a Primary/Active – Secondary/Standby state before you apply the LVM procedure.

Procedure

Check the HA pair status by entering the following command:
```
/opt/qradar/ha/bin/ha cstate
```
Add a hard disk to the system and ensure the same size hard disk is added to both primary and secondary hosts. Find the hard disk name by entering the following command:
```
lsblk
```
For example, sdb
Create a partition table on the new hard disk by entering the following command:
```
parted /dev/<HD name> mktable gpt
```
Create a partition for the whole disk by entering the following command:
```
parted /dev/<HD Name> mkpart xfs 1.00Mib 100%
```
Search for the name of the new partition by entering the following command:
```
lsblk
```
Typically, the device name with the number 1 at the end is the partition name.
For example, sdb1
Create the physical volume (PV) for this hard disk by entering the following command:
```
pvcreate /dev/<Partition name>
```
To add the storage, locate the volume group (VG). For example, storerhel is the VG for the /store and /transient directories. Locate VG by entering the following command:
```
vgs
```
Extend the VG to include the space from the new partition by entering the following command:
```
vgextend <Volume Group Name> /dev/<Partition name>
```
Note: This step is only required for all-in-one consoles and console devices.
It is recommended that all-in-one consoles and consoles devices have more storage on the transient and store volume. The transient volume should occupy 20% of the available space and the store volume should occupy 80% of the remaining space. This step is not required for any other type of appliances.
Warning: If you are extending the transient logical volume, you must complete this step before you extend the store logical volume.

Extend the transient logical volume by using 20% of the free space in the VG by entering the following command:
```
lvextend -l +20%FREE /dev/<VG Name>/transient
```
Extend the space for store LV by 100% of the remaining space by entering the following command:
```
lvextend -l +100%FREE /dev/<VG Name>/store
```
You can search for the path for the store file system. Generally, the path is /dev/mapper/<VG name>-<LV Name>.
For example, the path for the transient file system is /dev/mapper/storerhel-transient.
To find the file system name of the /transient directory, enter the following command:
```
xfs_info /transient | grep meta-data | sed "s/meta-data=//" | cut -d " " -f1
```
Note: This step is only required for all-in-one consoles and console devices.
For all-in-one consoles and console devices, grow the transient file system to fill free space only on the transient LV by entering the following command:
```
xfs_growfs /dev/mapper/<VG Name>-<LV Name>
```
Note: Perform this step is only on the primary/active host after the LVM procedure is completed on both primary and secondary hosts. This step triggers a full synchronization. This can take a significant amount of time depending on the size of /store and network configuration of the HA pair. During this time the high availability feature is not available.
Resize the DRBD device by entering the following command:
```
drbdadm resize store
```
To grow the /store, enter the following command:
```
xfs_growfs /dev/drbd0 # on Active primary
```