Eventually, i try out to vi lib/modules/2.6.28-11-server/modules.order in initrd.img-xxx to add support for mpt2sas, and then re-package initrd.img-xxx. It works now.
=== ... kernel/drivers/scsi/scsi_transport_sas.ko kernel/drivers/scsi/libsas/libsas.ko kernel/drivers/scsi/mpt2sas.ko kernel/drivers/scsi/scsi_transport_srp.ko ... ===
Eventually, i try out to vi lib/modules/ 2.6.28- 11-server/ modules. order in initrd.img-xxx to add support for mpt2sas, and then re-package initrd.img-xxx. It works now.
=== drivers/ scsi/scsi_ transport_ sas.ko drivers/ scsi/libsas/ libsas. ko drivers/ scsi/mpt2sas. ko drivers/ scsi/scsi_ transport_ srp.ko
...
kernel/
kernel/
kernel/
kernel/
...
===