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Branchcache files larger than 8MB are not cached RRS feed

  • Question

  • Hello all,

    Does anybody know why files that are bigger than 8MB are not cached by Branchcache hosted server? Smaller files are cached correctly.

    Also another concern is that once client machines start  downloading files from Branchcache server speed is very slow 100-200 kb/s in spite they are in local 100 Mpbs network.

    Our setup : 

    1 x FileServer (Windows server 2016 standard ,LANman server enabled for shared folders, shared folders have BranchCache caching enabled)

    1 x Branchcache server (Windows server 2012 r2 Standard, Branchcache hosted mode)

    3 x client PC (Windows 7 Enterprise, Branchcache hosted server FQDN configured, Configure branchcache for network files is 0)

    Thank you in advance!

    Nikola

    Wednesday, October 25, 2017 1:58 PM

All replies

  • Hi Nikola,

    Based on my knowledge, Branchcache only has the smaller size limit. The content need to be greater than 64KB in size. And for large files are divided into segments, which reach 32 MB in size.  A segment is a unit of discovery.  When downloading a large file, a client will search for one segment (32 MB) at a time.  These segments are further divided into blocks, which are 64KB in size.  After finding a peer with a segment of content, a BranchCache client will download data block by block.

    Anything wrong in the event viewer and what the results for get-bcstatus when for large files?

    https://social.technet.microsoft.com/Forums/windowsserver/en-US/7670144e-575a-4da2-b00d-293495f85f3c/branch-cache-files-that-are-regularly-updated?forum=windowsserver2008r2branchoffice

    And according to the blog, for the running slowly, please follow the steps to do a check.https://social.technet.microsoft.com/wiki/contents/articles/1296.branchcache-troubleshooting.aspx

    • Many computers drawing large amounts of content from one client in a short time period may impact desktop performance.
    • Use performance monitor to check for high service rates to peers. Examine BytesServedToPeers relative to BytesFromCache and BytesFromServer. The BranchCache service runs isolated in its own service host. Examine the CPU and memory consumption of the service host process housing the branch caching service.
    • Sustained high rates of service to peers may be evidence of a configuration problem in the branch office. Check to make sure that the other clients in the branch office are capable of service data.
    • Clear the cache on the affected client using the netsh branchcache flush command or reduce the cache size on the affected client.

    Best Regards,

    Mary


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    • Proposed as answer by Mary Dong Friday, November 3, 2017 7:18 AM
    Thursday, October 26, 2017 5:28 AM
  • You  say "branchcache for network files is 0" does that mean BranchCache for network files is not enabled?

    Typically larger files takes longer time to generate hashes for, so might be the case that if hashes are not created, it wont BranchCache.

    //A

    Monday, October 30, 2017 8:25 AM