
Google GKE: Local SSD disk performance is worse than standard persistent disk - siddontang
https://issuetracker.google.com/issues/113198296
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siddontang
We use fio

    
    
      fio -ioengine=psync -bs=32k -fdatasync=1 -thread -rw=write -size=10G -filename=test -name="PingCAP max throughput" -iodepth=4 -runtime=60 -numjobs=1 -group_reporting
    

and find that local disk has a bad performance than persistent disk.

A detailed report
[https://docs.google.com/document/d/1OP1VnGlQx__jW2i8sLfmZWqf...](https://docs.google.com/document/d/1OP1VnGlQx__jW2i8sLfmZWqfbVtRgqQIx2K98sMG3UA/edit)

Btw, if we remove -fdatasync=1 and use -direct=1 to bypass page cache, the
local SSD disk has a better performance.

Interesting. Does anyone know about it?

