HI Gkeerthy,
I agree with WhoodyZ, nice article. We are investigating the partition alignment quite a lot in the last few weeks, we need this information's for a skilled work of a trainee. We knew a lot of your information but some aspects are new and interesting (like the recommended cluster size on an Exchange server) Thanks for that.
Now we are using VMWare Fusion and I think we can't use the ESXi tools to determine the alignment of the virtual disk to the underlying physical disk but it would be nice to know if there is a possibility to verify this alignment in Fusion too. Is there a possibility to determine the virtual disk alignment in Fusion?
We also note that Debian Linux Squeeze (Version 6) aligned the partitions automatically on a 1 MiB boundary, so the starting sector of the first partition is always 2048 by default, so we don't need to setup the alignment by ourselves. But we are confused about the total number of cylinders we get back from the fdisk command. We read a lot about the disk geometry handling in modern systems and we know that the CHS addressing is outdated since the LBA addressing took place but every article we read told us that the default CHS values after an overrun of the maximum addressing units (8 Bit for the heads, 10 Bits for the cylinders and 6 Bits for the sectors) should display the maximum of 255 heads, 63 sectors and 1024 cylinders but we get back from fdisk a number of 1305 cylinders. In your article we can see 5221 cylinders. Can you explain this odd values?
And last but not least I guess that the matter of your article is also valid on SSDs at least for the Read Modify Write mechanism. In SSDs there is no mechanical positioning issue but there are also 4 KiB blocks and finally up to 512 KiB erasable blocks, so here should a 1 MiB alignment also best practice.
Thx & Bye Tom