The problem of inevitable degradation of disk subsystems performance caused by misaligned partitions dates back to the nineties. From being a headache for system administrators who wanted to get the most out of disk arrays, it has become crucial for all with appearance of SSD (Solid State Drive) and ultra high-capacity AFD (Advanced Format Drive) or 4K sector size drives. Moreover, the growing popularity of virtualized systems has aggravated the situation even more. Is the problem real? Just see it for yourself:
The root cause is in misalignment of logical partition sectors and actual physical sectors that leads to redundant read/write operations, which is critical for the overall performance and indirectly hardware lifespan. Sitting one logical level above, virtual hard drives are using page sizes similar to those of the modern AFD hard drive, thus they could easily get misaligned after a simple migration of a virtual machine from one VMware ESX Server to another. And if the host’s hard drive and virtual drives are both misaligned – the number of redundant read/write operations obviously doubles.