Disk Benchmarking Question - Mailing list pgsql-performance

From Dave Stibrany
Subject Disk Benchmarking Question
Date
Msg-id CAK17Jmku_RsBRHYKEVbT5KY9Cg1O4J6Zgpk4zYTXq2UQ1=LeMA@mail.gmail.com
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Responses Re: Disk Benchmarking Question
Re: Disk Benchmarking Question
List pgsql-performance
I'm pretty new to benchmarking hard disks and I'm looking for some advice on interpreting the results of some basic tests.

The server is:
- Dell PowerEdge R430
- 1 x Intel Xeon E5-2620 2.4GHz
- 32 GB RAM
- 4 x 600GB 10k SAS Seagate ST600MM0088 in RAID 10
- PERC H730P Raid Controller with 2GB cache in write back mode.

The OS is Ubuntu 14.04, I'm using LVM and I have an ext4 volume for /, and an xfs volume for PGDATA.

I ran some dd and bonnie++ tests and I'm a bit confused by the numbers. I ran 'bonnie++ -n0 -f' on the root volume.

Here's a link to the bonnie test results

The vendor stats say sustained throughput of 215 to 108 MBps, so I guess I'd expect around 400-800 MBps read and 200-400 MBps write. In any case, I'm pretty confused as to why the read and write sequential speeds are almost identical. Does this look wrong?

Thanks,

Dave



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