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sougandh555's avatar
sougandh555
Copper Contributor
Mar 27, 2020

ReFS requirement for high performance in CSV volume.

Hello    I have a requirement to use ReFS with CSV volumes. As per my last hours investigation i came to know we cannot use ReFS for booting. Here we are using Hyper V 2019. Can i use it for CSV? P...
Hyper-V
Windows Server
MysticFoxDE's avatar
MysticFoxDE
Copper Contributor
Jul 15, 2020

sougandh555 

Hi Sougandh,

 

"When you use ReFS with CSV volumes, the CSV volume will always run in file system redirection mode, which means that all the I/O operations are sent through the coordinator node. This can lead to severe performance impacts. ReFS is only recommended for use with Storage Spaces Direct (S2D)"

I can confirm the above statement 100% from several projects, and would absolutely advise against using ReFS with CSV volumes.

 

By the way, this behavior is by no means due to the ReFS specification. It is not officially mentioned in any Microsoft document that ReFS only runs in "file system redirection" mode for CSV volumes. Rather, this is an undocumented bug that has been reported to Microsoft several times. However, Microsoft seems to have been ignoring this bug for over a year. 🤮

 

Regards from Germany

 

Alex

 

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