The semaphore timeout period has expired. RRS feed

  • Question

  • Hi Team,

    I'm using DPM 2012 R2 Version in our environment, from last few days getting below error while initiating the backup through DPM.

    The DPM service was unable to communicate with the protection agent on (ID 52 Details: The semaphore timeout period has expired (0x80070079)) 

    Regards Mohit Sharma

    Tuesday, July 11, 2017 3:47 AM

All replies

  • Hello

    I am also getting this error intermittently when backing up directly to tape. I have dpm 2016 (5.0.342.0 UR4) on windows 2016 STD (Version     10.0.14393 Build 14393)<o:p></o:p>

    I have done the following on the dpmserver and client servers;<o:p></o:p>

    Created the TCP/IP maximum retransmission timeout parameter and set to 10 (have tried changing this to different values)<o:p></o:p>


    Created this;<o:p></o:p>

    [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Data Protection Manager\Agent] "BufferQueueSize"= 30 decimal (have tried changing this to different values)

    The exact error is ;

    The operation failed because of a protection agent failure. (ID 998 Details: The semaphore timeout period has expired (0x80070079))

    It would be great if you could shine any light on this please

    Tuesday, November 14, 2017 7:59 PM
  • Hello, 

    I've been using DPM since years ago, recently i've upgraded from DPM 2012 R2 to DPM 2016 UR4 on Windows 2016 with storage spaces. I'm backuping Hyper-V VMs running on hosts that I've also upgraded from Windows 2012 R2 to 2016.

    Everything was working fine with DPM 2012 UR14 and Windows 2012R2, I've started having issues after upgraded to 2016 with exactly the same hardware.

    Two mains problems:

    • Intermittent errors during Initial replication and/or sync of VMs (using RCT or Express Full) but also with backuping file server volume. The errors were : DPM has detected a checksum mismatch during data transfer over the network (ID 30087 Details: Internal error code: 0x809909B2)

    After tried every suggestion found on Internet (network firmware/driver updates, disabling RSS, Offload, etc...) I keep having this error. UNTIL it seems I've found a solution: I've realized that after the upgrade to 2016 I forgot to put back the Firewall IPsec encryption rules on the DPMRA process. After enabling IPSEC encryption between DPM and protected servers this issue disappeared!  I did not test with TLS instead neither DPM On-Wire compression maybe it could help also.

    • This issue solved, now I unfortunately get another ones: The DPM service was unable to communicate with the protection agent on XXXXXX. (ID 52 Details: The semaphore timeout period has expired (0x80070079))

    What you could check on your protected servers is that you find errors ID 121 in the Microsoft-Windows-DeviceSetupManager/Admin log like I had (thousands!):

    Error121If you have these errors, it's probably because your server doesn't have access to Internet to query device metadata information and you will find als the Warning ID 201 A connection to the Windows Metadata and Internet Services (WMIS) could not be established.

    The URL the servers try to contact is

    so i set the necessary proxy information to the winhttp service by using netsh winhttp set proxy.

    Since then it looks like now i don't get semaphore timeout expired anymore.

    I can't be 90% sure but looks like WMIS is triggered when a VSS Snapshot is mounted and in my casse it's strangely affected badly DPM backup process if WMIS has no access to Internet. 

    • Edited by Larry.B.IT Wednesday, April 25, 2018 9:56 AM
    Wednesday, April 25, 2018 9:54 AM
  • After further testing replica creation i still got the semaphore timeout errors. Finally fixing the error with WMIS didn't help.

    However setting the registry value TcpMaxDataRetransmissions to 10 as explained did the trick for me. I've been able to complete successfully the initial replica job of a file server volume (about 4 TB) and also have no more error during VM sync jobs.

    In the coming to start a protection of a 32TB file volume, will see the results.

    • Edited by Larry.B.IT Wednesday, May 2, 2018 11:41 AM
    Wednesday, May 2, 2018 11:41 AM
  • Larry, any updates?

    We are suffering from sempahore timeouts on BMR backups of 2016 servers and nothing has helped!

    Thursday, November 22, 2018 9:32 AM
  • Just as an update, increasing the spindle count on the Replica disk either solved or worked around the issue for us.

    Edit: No, still occurring, but less frequently because backups finish faster (I guess)

    Sunday, December 9, 2018 1:08 PM
  • Hello, sorry for the late answer.

    I was still not able to do the initial 32TB sync job and still had this error. I've had no choice to remain in deduped mode.The disadvantage is i had to giv up the secondary protection as it's not supported when the primary replica is in dedup mode.

    The fact is in dedup mode i've neved had issue with initial sync jobs, despite in my case the large amount of deduped data (about 16TB in one volume) and days needed to complete. For me, it looks like the DPM code for dedup job is more reliable vs "normal" sync job


    • Edited by Larry.B.IT Friday, April 5, 2019 9:19 AM
    Friday, April 5, 2019 9:18 AM