[Gluster-users] [Gluster-devel] iostat not showing data transfer while doing read operation with libgfapi

[satish kondapalli]

Hi,

I am running performance  test between fuse vs libgfapi.  I have a single
node, client and server are running on same node. I have NVMe SSD device as
a storage.

My volume info::

[root at sys04 ~]# gluster vol info
Volume Name: vol1
Type: Distribute
Volume ID: 9f60ceaf-3643-4325-855a-455974e36cc7
Status: Started
Number of Bricks: 1
Transport-type: tcp
Bricks:
Brick1: 172.16.71.19:/mnt_nvme/brick1
Options Reconfigured:
performance.cache-size: 0
performance.write-behind: off
performance.read-ahead: off
performance.io-cache: off
performance.strict-o-direct: on


fio Job file::

[global]
direct=1
runtime=20
time_based
ioengine=gfapi
iodepth=1
volume=vol1
brick=172.16.71.19
rw=read
size=128g
bs=32k
group_reporting
numjobs=1
filename=128g.bar

While doing sequential read test, I am not seeing any data transfer on
device with iostat tool.  Looks like gfapi engine is reading from the cache
because i am reading from same file with different block sizes.

But i disabled  io cache  for my volume. Can someone help me  from where
fio is reading the data?


Sateesh
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