I was using fdisk and was wondering why partitions start at sector 2048 instead of 1
In: 1
Where is the info about partitions stored? Can’t be *in* a partition, obviously. It’s at the first sectors of the disk.
This is simplified but…
Flash memory storage, aka solid state drives, aka SSDs, organise the individual memory cells into pages, quite a large amount of storage.
You cant change individual bits or bytes, only erase whole pages and rewrite them. If you rewrite a small amount of data which just spans two pages, it’s inefficient. So the file system is laid out so as match the file block allocation with the flash pages, and thus try and minimise the number of pages being changed on the SSD. This means starting the file system in a partition at a page boundary, and sector 2048 is chosen as the next likely chunk that’s non zero.
Partitions on a hard drive typically start at sector 2048 instead of sector 0 for a few reasons. One reason is that the first few sectors of a hard drive are reserved for the Master Boot Record (MBR), which contains information about the partitions on the drive. By starting partitions at sector 2048, there is enough space for the MBR and any additional boot code that may be needed. Additionally, starting partitions at sector 2048 aligns them on a 2048-sector (1MB) boundary, which can improve performance when reading and writing large files. This is because most hard drives have internal physical block sizes of 4KB or 8KB, so starting partitions on a 2048-sector boundary allows them to be aligned with the physical block size of the drive.
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