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Summary



A Block backup to NetApp storage appears to stop. The job log continues to report the same transfer metrics, until the job is canceled manually. Timestamp negotiation between the NetApp storage system and client may be the cause of the problem.

Symptoms



The job log prints messages from sssvh regarding checking the status of the data transfer. However the transfer metrics do not change over a long period of time. An example of the job log follows:

x.x.x.x sssvh Fri Jan 25 17:36:33 2008 SNBSVH_283W Task 6 data transfer is not currently in progress

x.x.x.x sssvh Fri Jan 25 17:36:33 2008 SNBSVH_284W Check status of relationship(/vol/HostA/[JobBck]HOSTA@A162EFE32B8611DCA90E806E6F6E6963) on node(Filer01)

x.x.x.x sssvh Fri Jan 25 17:36:33 2008 SNBSVH_234J Task 7 has transfered 585.4 MB

x.x.x.x sssvh Fri Jan 25 17:36:33 2008 SNBSVH_283W Task 8 data transfer is not currently in progress

x.x.x.x sssvh Fri Jan 25 17:36:33 2008 SNBSVH_284W Check status of relationship(/vol/HostA/[JobBck]HOSTA@A162EFE52B8611DCA90E806E6F6E6963) on node(Filer01)

x.x.x.x sssvh Fri Jan 25 17:41:37 2008 SNBSVH_283W Task 6 data transfer is not currently in progress

x.x.x.x sssvh Fri Jan 25 17:41:37 2008 SNBSVH_284W Check status of relationship(/vol/HostA/[JobBck]HOSTA@A162EFE32B8611DCA90E806E6F6E6963) on node(Filer01)

x.x.x.x sssvh Fri Jan 25 17:41:37 2008 SNBSVH_234J Task 7 has transfered 585.4 MB

x.x.x.x sssvh Fri Jan 25 17:41:37 2008 SNBSVH_283W Task 8 data transfer is not currently in progress

x.x.x.x sssvh Fri Jan 25 17:41:37 2008 SNBSVH_284W Check status of relationship(/vol/HostA/[JobBck]HOSTA@A162EFE52B8611DCA90E806E6F6E6963) on node(Filer01)

............

.x.x.x sssvh Fri Jan 25 18:50:45 2008 SNBSVH_283W Task 6 data transfer is not currently in progress

x

x.x.x.x sssvh Fri Jan 25 18:50:45 2008 SNBSVH_284W Check status of relationship(/vol/HostA/[JobBck]HOSTA@A162EFE32B8611DCA90E806E6F6E6963) on node(Filer01)

x.x.x.x sssvh Fri Jan 25 18:50:45 2008 SNBSVH_234J Task 7 has transfered 585.4 MB

x.x.x.x sssvh Fri Jan 25 18:50:45 2008 SNBSVH_283W Task 8 data transfer is not currently in progress

x.x.x.x sssvh Fri Jan 25 18:50:45 2008 SNBSVH_284W Check status of relationship(/vol/HostA/[JobBck]HOSTA@A162EFE52B8611DCA90E806E6F6E6963) on node(Filer01)

The status message repeats about every 5 minutes. If left unattended, the job continues to run for hours, until the administrator cancels it.



Resolution



To correct this issue, try disabling the tcp_do_rfc1323 parameter on the NetApp storage system, as follows:

  1. On the NetApp storage system, use the following commands to verify the timestamp status, which may be enabled by default:

    priv set diag
    printflag tcp_do_rfc1323

    A setting of 1 indicates that timestamps are enabled.
  2. To disable the parameter, run:

    setflag tcp_do_rfc1323 0

    Note:     A reboot is not required
  3. To restore normal administrator privileges, run:

    priv set admin