Similar to Intel and Dell, LSI RAID controllers have "Patrol Read" feature to spot a drive failure before the failure can damage data, therefore, protect data interigation.

Is it necessary to turn it on for SSD?

By default, it sets off by LSI for SSD, but you can enable it if you wish.

Generally speaking, SSDs have limited Writes and Reads, Periodict Patrol read will reduce SSD life. So, in my opinon, depends on the types of SSDs you are using, for enterprise SSD, you should leave it off. The main reason of doing this is that Enterprise SSD are more realiable and has protections to reduce damaging cells due to exessive writes.

To check the patrol read status of your LSI RAID card.

# MegaCli64 -AdpPR -Info -aALL
                                     
Adapter 0: Patrol Read Information:

Patrol Read Mode: Auto
Patrol Read Execution Delay: 168 hours
Number of iterations completed: 120
Current State: Stopped
Patrol Read on SSD Devices: Disabled

To enable Patrol Read for SSD

MegaCli -AdpPR SSDPatrolReadEnbl

To disable Patrol Read for SSD

SMegaCli -AdpPR SDPatrolReadDsbl