Hard disk is not detecting in ESXi 4.1.0

[rameuniver]

We have the P410i array controller we have RAID-0 is configured for some set of disks and RAID-5 is configured for some set of disk. ESXi installed on RAID-0 and virtual machines are stored on RAID-5. Now we have added two hard drives, we want expand our RAID-5 datastore. But after adding two hard drives physically, it is not showing in esxi4

[a_p_ · Accepted solution]

I really hope you do have RAID-1 (mirroring) configured rather than RAID-0 (spanning).

Anyway in order for the OS (ESXi) to see the additional disk space you need to add these two disks to the RAID-5 set using the ACU (Array Configuration Utility) on the SmartStart CD. This operation however, requires the presence of BBWC (battery buffered write cache) attached to the controller.

Caution: Make sure the resulting logical volume does not exceed 2TB minus 512 bytes, otherwise the ESXi host will not recognize the volume anymore!

If the capacity of the RAID-5 set with the additional two disks exceeds this limit, then create an additional logical volume rather than to resizing the existing one.

If you don't have BBWC, your only option is to add these two disks as another RAID-1 set.

André