Very slow start up

luiceur · March 3, 2021, 07:44

Hello,

When running on large numbers of cores, we have noticed that the start up of the solver takes very long. We haven't seen it before, and the simulations started almost straight away, but now it takes long time waiting:

Code:

Pstream initialized with:
    floatTransfer      : 0
    nProcsSimpleSum    : 0
    commsType          : nonBlocking
    polling iterations : 0
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

Is there a reason for this? Can anything be done about this?

Cheers

olesen · March 3, 2021, 15:08

Filesystem related?
You don't say how many cores nor which version you are using.

luiceur · March 3, 2021, 17:15

It could be filesystem related... yes but I cannot say for sure. Certainly I have not seen this behaviour before.
We are talking about 8000+ cores with OF v1912

March 3, 2021, 07:44	Very slow start up	#1
luiceur New Member NA Join Date: Oct 2015 Posts: 10 Rep Power: 11	Hello, When running on large numbers of cores, we have noticed that the start up of the solver takes very long. We haven't seen it before, and the simulations started almost straight away, but now it takes long time waiting: Code: Pstream initialized with: floatTransfer : 0 nProcsSimpleSum : 0 commsType : nonBlocking polling iterations : 0 fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10) allowSystemOperations : Allowing user-supplied system call operations // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Is there a reason for this? Can anything be done about this? Cheers Last edited by luiceur; March 3, 2021 at 07:46. Reason: formatting

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March 3, 2021, 15:08		#2
olesen Senior Member Mark Olesen Join Date: Mar 2009 Location: https://olesenm.github.io/ Posts: 1,715 Rep Power: 40	Filesystem related? You don't say how many cores nor which version you are using.

March 3, 2021, 17:15		#3
luiceur New Member NA Join Date: Oct 2015 Posts: 10 Rep Power: 11	It could be filesystem related... yes but I cannot say for sure. Certainly I have not seen this behaviour before. We are talking about 8000+ cores with OF v1912