Hi list
I was wondering:
When i start
fio --name=/srv/mail/test --size=10M --direct=1 --runtime=60
--time_based --group_reporting --refill_buffer --rw=read --numjobs=1
I get as result:
read : io=1177.4MB, bw=20093KB/s, iops=5023, runt= 60000msec
But when I do a
fio --name=/srv/mail/test --size=10G --direct=1 --runtime=60
--time_based --group_reporting --refill_buffer --rw=read --numjobs=1
The result is:
read : io=976692KB, bw=16278KB/s, iops=4069, runt= 60001msec
(decrease of 20%, in some scenarios it's even worse with more than 30%)
So how does the file size influence the speed (iops, bandwith)? My
understanding was that it is not important from which filesize we are
reading from - important is the block size and if the filesize is not
big enough, fio just restarts to read the file from the beginning. How
can that be explained? And which sizes should be used to get reliable
results?
Thanks
Josef
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