>>>>> "edm" == Eric D Mudama <edmud...@bounceswoosh.org> writes:
edm> What you're suggesting is exactly what SSD vendors already do. no, it's not. You have to do it for them. edm> They present a 512B standard host interface sector size, and edm> perform their own translations and management inside the edm> device. It is not nearly so magical! The pages are 2 - 4kB. They are this size for nothing to do with the erase block size or the secret blackbox filesystem running on the SSD. It's because of the ECC, because the reed-solomon for the entire block must be recalculated if any of the block is changed. Therefore, changing 0.5kB means: for a 4kB page device: * read 4kB * write 4kB for a 2kB page device: * read 2kB * write 2kB and changing 4kB at offset <integer> * 4kB means: for a 4kB device: * write 4kB for a 2kB device: * write 4kB It does not matter if all devices have the same page size or not. Just write at the biggest size, or write at the appropriate size if you can. The important thing is that you write a whole page, even if you just pad with zeroes, so the controller does not have to do any reading. simple. the problem with big-sector spinning hard drives and alignment/blocksize is exactly the same problem. non-ZFS people discuss it a lot becuase ZFS filesystems start at <integer> * <rather large block> offset, thanks to all the disk label hokus pocus, but NTFS filesystems often start at 16065 * 0.5kB
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