Messages in this thread | | | From | Jeff Johnson <> | Subject | 2.6 diskstats and 4096 sector block devices? | Date | Fri, 13 May 2016 12:15:30 -0700 |
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Greetings,
I am analyzing output in /proc/diskstats for block devices that have a 4096B physical and logical sector size. 4KN or 4K-native disk drives.
8 33 sdc1 1289 0 10312 5893 3258606 53 1668254992 16804002 31 583987 16807101
Fields 3 and 7 are sectors read and written respectively. For operations on a 4KN device should fields 3 and 7 be interpreted as number of 4K sectors written (total transferred = N * 8) or is each 4K sector operation reflected as 8 ticks to N?
I am expecting 1MB transfers to the device and using 'delta[field7] / delta[field5]' getting 128 which would point to diskstats handling everything in terms of 512B operations.
To multiply by 8 or not to multiply by 8, that is the question.. :-)
Thanks,
--Jeff
------------------------------ Jeff Johnson Co-Founder Aeon Computing
jeff.johnson "dot" aeoncomputing.com www.aeoncomputing.com
4170 Morena Boulevard, Suite D - San Diego, CA 92117
High-performance Computing / Lustre Filesystems / Scale-out Storage
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