Device-Mapper's "asm-striped" target is used to create a striped (i.e. RAID-0) device across one or more underlying devices. Data is written in "chunks", with consecutive chunks rotating among the underlying devices. This can potentially provide improved I/O throughput by utilizing several physical devices in parallel. However, in order to gain maximum I/O performance between slow and fast device, there is a ratio to set up the chunk size among these device. Parameters: <num devs> <chunk size> <ratio> [<dev path> <offset>]+ <num devs>: Number of underlying devices. <chunk size>: Size of each chunk of data. Must be at least as large as the system's PAGE_SIZE. <ratio>: The proportion of per io size, it is the times as much as 1 chunk size <dev path>: Full pathname to the underlying block-device, or a "major:minor" device-number. <offset>: Starting sector within the device. Documentation/device-mapper/asymmetric-striped.txt | 85 ++++ drivers/md/Kconfig | 11 + drivers/md/Makefile | 1 + drivers/md/dm-asymmetric-stripe.c | 556 +++++++++++++++++++++ drivers/md/dm.c | 5 + include/linux/device-mapper.h | 15 + 6 files changed, 678 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
