256 tokens: root@cas9:/sys/block/dm-0# blockdev --report RO RA SSZ BSZ StartSec Size Device rw 256 512 4096 0 67108864 /dev/ram0 rw 256 512 4096 0 67108864 /dev/ram1 rw 256 512 4096 0 67108864 /dev/ram2 rw 256 512 4096 0 67108864 /dev/ram3 rw 256 512 4096 0 67108864 /dev/ram4 rw 256 512 4096 0 67108864 /dev/ram5 rw 256 512 4096 0 67108864 /dev/ram6 rw 256 512 4096 0 67108864 /dev/ram7 rw 256 512 4096 0 67108864 /dev/ram8 rw 256 512 4096 0 67108864 /dev/ram9 rw 256 512 4096 0 67108864 /dev/ram10 rw 256 512 4096 0 67108864 /dev/ram11 rw 256 512 4096 0 67108864 /dev/ram12 rw 256 512 4096 0 67108864 /dev/ram13 rw 256 512 4096 0 67108864 /dev/ram14 rw 256 512 4096 0 67108864 /dev/ram15 rw 16 512 4096 0 800166076416 /dev/sda rw 16 512 4096 2048 800164151296 /dev/sda1 rw 16 512 4096 0 644245094400 /dev/dm-0 rw 16 512 4096 0 2046820352 /dev/dm-1 rw 16 512 4096 0 1023410176 /dev/dm-2 rw 16 512 4096 0 800166076416 /dev/sdb
512 tokens: root@cas10:/sys/block# blockdev --report RO RA SSZ BSZ StartSec Size Device rw 256 512 4096 0 67108864 /dev/ram0 rw 256 512 4096 0 67108864 /dev/ram1 rw 256 512 4096 0 67108864 /dev/ram2 rw 256 512 4096 0 67108864 /dev/ram3 rw 256 512 4096 0 67108864 /dev/ram4 rw 256 512 4096 0 67108864 /dev/ram5 rw 256 512 4096 0 67108864 /dev/ram6 rw 256 512 4096 0 67108864 /dev/ram7 rw 256 512 4096 0 67108864 /dev/ram8 rw 256 512 4096 0 67108864 /dev/ram9 rw 256 512 4096 0 67108864 /dev/ram10 rw 256 512 4096 0 67108864 /dev/ram11 rw 256 512 4096 0 67108864 /dev/ram12 rw 256 512 4096 0 67108864 /dev/ram13 rw 256 512 4096 0 67108864 /dev/ram14 rw 256 512 4096 0 67108864 /dev/ram15 rw 16 512 4096 0 800166076416 /dev/sda rw 16 512 4096 2048 800164151296 /dev/sda1 rw 16 512 4096 0 800166076416 /dev/sdb rw 16 512 4096 2048 800165027840 /dev/sdb1 rw 16 512 4096 0 1073741824000 /dev/dm-0 rw 16 512 4096 0 2046820352 /dev/dm-1 rw 16 512 4096 0 1023410176 /dev/dm-2 2017-02-18 21:41 GMT+01:00 Bhuvan Rawal <bhu1ra...@gmail.com>: > Hi Ben, > > If its same on both machines then something else could be the issue. We > faced high disk io due to misconfigured read ahead which resulted in high > amount of disk io for comparatively insignificant network transfer. > > Can you post output of blockdev --report for a normal node and 512 token > node. > > Regards, > > On Sun, Feb 19, 2017 at 2:07 AM, Benjamin Roth <benjamin.r...@jaumo.com> > wrote: > >> cat /sys/block/sda/queue/read_ahead_kb >> => 8 >> >> On all CS nodes. Is that what you mean? >> >> 2017-02-18 21:32 GMT+01:00 Bhuvan Rawal <bhu1ra...@gmail.com>: >> >>> Hi Benjamin, >>> >>> What is the disk read ahead on both nodes? >>> >>> Regards, >>> Bhuvan >>> >>> On Sun, Feb 19, 2017 at 1:58 AM, Benjamin Roth <benjamin.r...@jaumo.com> >>> wrote: >>> >>>> This is status of the largest KS of these both nodes: >>>> UN 10.23.71.10 437.91 GiB 512 49.1% >>>> 2679c3fa-347e-4845-bfc1-c4d0bc906576 RAC1 >>>> UN 10.23.71.9 246.99 GiB 256 28.3% >>>> 2804ef8a-26c8-4d21-9e12-01e8b6644c2f RAC1 >>>> >>>> So roughly as expected. >>>> >>>> 2017-02-17 23:07 GMT+01:00 kurt greaves <k...@instaclustr.com>: >>>> >>>>> what's the Owns % for the relevant keyspace from nodetool status? >>>>> >>>> >>>> >>>> >>>> -- >>>> Benjamin Roth >>>> Prokurist >>>> >>>> Jaumo GmbH · www.jaumo.com >>>> Wehrstraße 46 · 73035 Göppingen · Germany >>>> Phone +49 7161 304880-6 <07161%203048806> · Fax +49 7161 304880-1 >>>> <07161%203048801> >>>> AG Ulm · HRB 731058 · Managing Director: Jens Kammerer >>>> >>> >>> >> >> >> -- >> Benjamin Roth >> Prokurist >> >> Jaumo GmbH · www.jaumo.com >> Wehrstraße 46 · 73035 Göppingen · Germany >> Phone +49 7161 304880-6 <07161%203048806> · Fax +49 7161 304880-1 >> <07161%203048801> >> AG Ulm · HRB 731058 · Managing Director: Jens Kammerer >> > > -- Benjamin Roth Prokurist Jaumo GmbH · www.jaumo.com Wehrstraße 46 · 73035 Göppingen · Germany Phone +49 7161 304880-6 · Fax +49 7161 304880-1 AG Ulm · HRB 731058 · Managing Director: Jens Kammerer
