Question: I had two drives partitioned the same and running two RAID partitions on each.
One died and I replaced it under warranty for the same model.
While trying to partition it, the first partition can only start on sector 2048, instead of 63 that was before. Drive have different geometry as previous and remaining ones. (Fewer heads/more cylinders)
Old drive:
$ sudo fdisk -c -u -l /dev/sdb Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000aa189 ?Device Boot ?Start ?End ?Blocks ?Id ?System/dev/sdb1 ?* ?63 ?174080339 ?87040138+ ?83 ?Linux/dev/sdb2 ?174080340 ?182482334 ?4200997+ ?82 ?Linux swap / Solaris/dev/sdb3 ?182482335 ?3907024064 ?1862270865 ?fd ?Linux raid autodetect
Remanufactured drive received from warranty:
$ sudo fdisk -c -u -l /dev/sdaDisk /dev/sda: 2000.4 GB, 2000398934016 bytes81 heads, 63 sectors/track, 765633 cylinders, total 3907029168 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000d0b5d ?Device Boot ?Start ?End ?Blocks ?Id ?System/dev/sda1 ?2048 ?…
Why is that?
Answer: Because your old disc was partitioned with a old utility, such as the Linux fdisk, that uselessly implemented track-alignment using the entirely fake disc geometry that you see reported, and your new disc has been or is being partitioned by a newer utility that (by default) aligns to 1MiB boundaries instead. ?
Further reading
- Jonathan de Boyne Pollard (2011). The gen on disc partition alignment. ?Frequently Given Answers.