Partition alignment on MegaRAID RAID 1 with 4k sector (advanced format) drives

Yes, it is made for 4k sector alignment.

With 1.1 and 1.2 superblocks, space is reserved at the start of each disk so that the superblock doesn't get trampled. The superblock creation code forces this reserved space to be a multiple of 4kB. All physical reads are offset from the end of this reserved space, not from the end of the superblock. This therefore preserves the alignment for any sector size that divides evenly into 4kB.

If you're interested, here is the proof from the mdadm source code (super1.c):

/* force 4K alignment */
reserved &= ~7ULL;
sb->data_offset = __cpu_to_le64(reserved);

And this data_offset parameter is used by the RAID1 code in the kernel to offset the physical reads, e.g. in the read path:

read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset

S.M.A.R.T. is not the final word in disk or storage monitoring!! It's a component, but modern RAID controllers use it along with other methods to determine drive and array health.

I'm assuming this is a PERC controller in a Dell PowerEdge server.

The normal Linux-friendly approach to health monitoring of Dell hardware is to install the Dell OMSA agents for Linux via Yum - http://linux.dell.com/wiki/index.php/Repository/OMSA#Yum_setup

yum install srvadmin-all will install the full suite of agents. Once installed, you can use the omreport command to get information about your array.

Examples:

$ omreport storage vdisk

$ omreport storage pdisk controller=0

$ omreport storage vdisk controller=0 vdisk=1