Importance of the fsync value

[mir]

Hi all,

I have been wondering. Is a high fsync value really needed if all your vm's and ct's run on a remote shared storage array?

If so, what specific gains do you get from a high fsync value in this specific situation?

 

[dietmar]

If so, what specific gains do you get from a high fsync value in this specific situation?

Form 'man fsync':

> fsync() transfers ("flushes") all modified in-core data of (i.e., modified buffer cache pages for) ...

Many application use that to protect data (databases, but also many other applications).

So this can become the bottleneck.

 

[mir]

Form 'man fsync':

> fsync() transfers ("flushes") all modified in-core data of (i.e., modified buffer cache pages for) ...

Many application use that to protect data (datatbases, but also many other applications).

So this can become the bottleneck.

Ok. But the need for fsync is less important if all virtual servers run on remote storage arrays?

 

[dietmar]

Ok. But the need for fsync is less important if all virtual servers run on remote storage arrays?

Why?

 

[dietmar]

Ok. But the need for fsync is less important if all virtual servers run on remote storage arrays?

You need fast fsync on the remote storage then (fsync on local storage is not important then).

 

[mir]

You need fast fsync on the remote storage then (fsync on local storage is not important then).

Exactly. This was my point