GPT on 512B sector disk
 

I'm about to reinstall one server and noticed that this particular server has older disks with 512B physical sector size, while other machines have disks with 4K physical sector size. On newer disks we have GPT, but what about these older ones?

Is there any performance penalty for using GPT on 512B sectors (like translation overhead when using 4K disks with MBR)? Is it even possible to use GPT on these disks?

I know GPT purpose is to enable use of larger disks (> 2.2 TB), but backup partition table is nice feature I'd like to have even on these disks.

GPT works regardless of physical block size. All modern partitioning schemes deal with linear block numbers (the LBA addressing scheme), meaning the start and end of a partition is specified relative to block 0. The size of the block is not considered at all.

The only instance when any kind of "translation" takes place, is when you use drives with 4k sectors that emulate 512b sectors, and that translation occurs within the drive itself. The partition table still deals with LBA addresses.

The kernel only parses the partition table when a device is detected or when the appropriate system call is performed, such as when you run partprobe. The table is not referenced when file systems are being accessed, so no overhead can be present regardless of how the partitioning scheme works.

Thanks for explanation.

Marking this thread as solved.