How does the kernel determine minimum_io_size and optimal_io_size?
Issue
- How does the kernel derive the values for
minimum_io_size
andoptimal_io_size
? - Can we change the
minimum_io_size
andoptimal_io_size
?- How do we change
optimal_io_size
?
- How do we change
- Enabling storage vendor host mode 68 ("Support Page Reclamation for Linux") in our storage system (HDS VSP G200) causes the I/O size to change from "I/O size (minimum/optimal): 512 bytes / 512 bytes" to "I/O size (minimum/optimal): 65536 bytes / 44040192 bytes". Why does the HDS storage box change its reported I/O size to 65536/44040192 when storage vendor host mode 68 is turned on?
Environment
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 6
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