tw_cli is the CLI for monitoring and maintaining 3ware RAID controllers. It can be used for all maintenance operations that can be performed through the 3dmd daemon or the system BIOS.

| list controllers in the machine

info 

| list the disks on controller 1 and their grouping into RAID arrays

info c1

| list the disks in RAID unit 2 and their status within the array. Useful to find out which disk is bad in a DEGRADED array.

info c1 u2

| list the status of an individual disk

info c1 p2

| for experts: show low-level error log output for the controller

info c1 diag

| remove disk p2 from c1 array

maint remove c1 p2

It varies based on your version of tw_cli.

| rescan or add you can use any one of them based on version OR try from top to bottom stop when succeed

rescan c1
OR
maint rescan c1
OR
maint add c1 p2

| After rescan you need to rebuild

maint rebuild c1 u2 p2

maint createunit c1 rraid1 p2:3

maint createunit c1 rraid5 p0:1:2:3:4:5:6

maint createunit c1 rspare p2