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Disk writes very slow on Linux compared to Windows

ausadbaMay 9 2018 — edited May 15 2018

Hi,


I have 2 VMs setup. 1 has OEL 7.4 64bit installed. The other one has Windows Server 2012R2.

I am running SQL Server 2017 in both operating systems.

I am trying the run some data generation SQL statements.


This consistently takes 10 seconds to complete in the Windows VM

but on Oracle Linux, it consistently takes 40+ seconds.

While seeing the disk activity on the host machine, the disk keeps writing at 4MBps and disk gets quite busy.

But in the windows VM I don't see a similar behaviour and the query finishes within 10 seconds.

Some additional threads I opened in Virtualbox and MSDN

https://forums.virtualbox.org/viewtopic.php?f=6&t=87870&sid=df2abb64d193a8a6ae18fb4e6e68a20a

https://social.msdn.microsoft.com/Forums/sqlserver/en-US/ce546c5c-0b7e-4a27-aeeb-fdccd3c46e0f/sql-server-4-times-slow-on…

Does anyone know what I should look at to tune? I tried modifying the below parameters but it did not help

vm.dirty_background_bytes = 0

vm.dirty_background_ratio = 10

vm.dirty_bytes = 0

vm.dirty_expire_centisecs = 3000

vm.dirty_ratio = 30

vm.dirty_writeback_centisecs = 500

vm.dirtytime_expire_seconds = 43200

Thanks!

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Locked on Jun 11 2018
Added on May 9 2018
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