#11796: Support for "4K-native" hard disks.
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Reporter: pulkomandy | Owner: nobody
Type: enhancement | Status: new
Priority: normal | Milestone: Unscheduled
Component: - General | Version: R1/Development
Resolution: | Keywords:
Blocked By: | Blocking:
Platform: All |
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Comment (by pulkomandy):
In SDHC and SDXC cards, this field was removed from the CSD and the sector
size is fixed to 512 bytes.
To test this, you would have to find a 2GB or 4GB non-SDHC card, of which
there are not many (SDHC was specified before 2GB cards became common).
The question here is mainly what happens for MBR and GPT, since they store
partition offsets in LBA numbers. If the sectors on disk are larger, are
we expected to store sizes in multiples of 512 bytes regardless of it, or
are we expected to store them in multiples of the sector size used by the
disk?
The SATA driver is also not currently able to handle sectors if size other
than 512. There are some anouncements for migrating to "4K native" disks
(https://www.seagate.com/tech-insights/advanced-format-4k-sector-hard-
drives-master-ti/ for example), Windows and Linux support it, but I'm not
sure where to buy one such drive.
There are no problem at the driver API level where we just use off_t, so
it is up to each driver to do the conversion from off_t to blocks. But we
should also make sure to keep reads and writes aligned to sectors (which I
think we can do using the block cache and DMA constraints).
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Ticket URL: <https://dev.haiku-os.org/ticket/11796#comment:3>
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