Christian, Otto, Thanks for your feedback on this one.... Ill research it further, but NTFS has 4K, 8K 32K and 64K Allocation units on the filessystem and for Microsoft windows running Exchange or Database workloads they were recommending alignment of the NTFS partitions on the 1MB offset also.
>From Otto's, explanation (Thanks) of 1/16 blocks would potentially cross a boundary of the storage subsystem, 6.25% of reads(or writes) could result in a double Read ( or double write) of course the write issue is a bigger problem for the SSDs.. I can configure the partitions how I want ,for now anyway, Ill do a little digging on FFS and FFS2 and see how the filesystem database (or table) is structured... Thanks for the feedback it is very helpful to me.... All the best, Tom Smyth On Wed, 21 Apr 2021 at 15:25, Christian Weisgerber <na...@mips.inka.de> wrote: > > Tom Smyth: > > > if you were to have a 1MB file or a database that needed to read 1MB > > of data, i > > f the partitions are not aligned then > > your underlying storage system need to load 2 chunks or write 2 > > chunks for 1 MB of data, written, > > You seem to assume that FFS2 would align a 1MB file on an 1MB border > within the filesystem. That is not case. That 1MB file will be > aligned on a blocksize border (16/32/64 kB, depending on filesystem > size). Aligning the partition on n*blocksize has no effect on this. > > -- > Christian "naddy" Weisgerber na...@mips.inka.de -- Kindest regards, Tom Smyth.
