OSSV reports "Unexpected read select while no data pending" for all Drives on Windows Server

[REISTTELECOM]

Hello Community,

we rolled out OSSV on several Windows Servers and now the Windows Application Log reports the Following Error. ID "4102", Source "SnapVault".

D:\ <Destination Filer>:/vol/<Destination Volume>/Dxx Unexpected read select while no data pending

I found several Community Discussions regarding that but no solution overall.

The OSSV Install Log shows that we have the following Version is installed.

NetApp Host Agent version 2.7 (2.7.0.2203)

Agent Core Library version 2.7 (2.7.0.2203)

The destination filer runs the following Ontap version

NetApp Release 8.1.2P4 7-Mode:

Attached you'll find the latest logfile.

Want to ask if this is a configuration or known Problem and how to solve it?

Best Regards

Daniel

[ASHWINPAWARTESL]

Uncheck the box 'Run estimator before each backup' in the OSSV configurator and check if that helps.

Also, check the SnapMirror log for any error on the filer (/etc/log/snapmirror).

Thanks,

-Ashwin

[REISTTELECOM]

Hoi Ashwin,

thanks a lot for your reply! Have unchecked the estimator and will have a look into the logs. Will let you know as soon as I have any news.

Best Regards

Daniel

[REISTTELECOM]

Hoi Ashwin,

a big SORRY for late reply. Have unchecked the box 'Run estimator before each backup' in the OSSV configurazor and still get these messages.

E:\<Destination Filer>:/vol/ossv_v_lx_<Servername>/Exx Unexpected read select while no data pending

Had a look at the Snapmirror Log and have nearly at the same time the following message.

dst Fri Jun 14 03:48:12 CES <Server Name>:E:\ <Destination Filer>:/vol/ossv_v_lx_<Server Name>/Exx Abort (could not read from socket)

So, uncheck the box didn't solve the problem.

Thanks a lot for your help.

Best Regards

Daniel

[ASHWINPAWARTESL]

Hi Daniel,

That's alright. No need to sorry . I guess, its a community and we are all busy and we hope there is always someone or the other to pitch in.

What is the snapvault settings on filer?
filer>options snapvault

Please send me this log file:

To collect, go to (for windows):

C:\Program Files\netapp\snapvault\bin>OSSVINFO.exe -s filer -l root:password ossvinfo

'Ossvinfo' is saved in /bin directory in the same path.

Thanks,

-Ashwin

[REISTTELECOM]

Hoi Ashwin,

thanks a lot for your answer.

Snapvault Stettings are:

> options snapvault

snapvault.access             all

snapvault.enable             on

snapvault.lockvault_log_volume

snapvault.nbu.archival_snap_default on

snapvault.ossv.compression   on

snapvault.preservesnap       off

snapvault.snapshot_for_dr_backup vsm_base_only

Please find the output of OSSVINFO attached. Thanks a lot.

Daniel

[ASHWINPAWARTESL]

Hi Daniel,

I can't seem to find anything wrong with the ossv config file, but this error is indicating something to do with the "network", but I can't figure out what it might be. Lets try to isolate it further..

On the filer (for - snapvault.access) , remove 'all' and put the IP address instead as shown below, and run the backups again. (Note: if there are multiple ossv hosts, then comma seprated values are allowed.)

filer>options snapvault.access host=x.x.x.x

Also, try running packet trace, may be we can catch something.

filer> pktt start all -i x.x.x.x -d /etc/log
Note: ‘-i’  is the IP address of ossv host, and '-d' is used to save the files to the given directory.

Thanks,

-Ashwin

[REISTTELECOM]

Hoi Ashwin,

we have about 30 Hosts using Snapvault, is there any character limitation in options snapvault.access host ? Will it help to do the packet trace before removing the host? Or do you suggest to change first the option and then do the packet trace?

Best Regards

Daniel

[ASHWINPAWARTESL]

I am not aware of any limitation as such.

But, lets take another route, before chaging the 'all' setting for snapvault host access, Add IP/hostname entry for OSSV host that is expereincing this issue on the filer's /etc/hosts file.

once added, entry would look something like this:

filer>rdfile /etc/hosts
x.x.x.x  ossvhostname

See if this helps.

Thanks,

-Ashwin

[paul_wolf]

Do any of these help?

https://support.quest.com/SolutionDetail.aspx?id=SOL81255

http://it.toolbox.com/blogs/borgblog/typical-work-day-19788

Have you checked that the VSS provider is fucntioning correctly? Can you create a shadow copy manually?

'vssadmin create shadow [path]'

[REISTTELECOM]

Hello Together,

I know it's a community but anyway a big SORRY for late reply. I had a look on the links send by paul and did the following.

• Set the retry count of all Volumes from 2 Servers from defazult 2 to 5
• had a look if VSS Shadows could be taken manually. Was successfull for all Drives (see output below)
• checked with the colleague of our network team the switchport and changed the from Auto negotiate to 1Gbit fix on both the Switch and Nic

If this won't help I will try tomorrow the options snapvault.access host suggested by Ashwin.

A big THANK YOU to you both for your help. Really appreciate it.

C:\Users\ylb>vssadmin create shadow /For=D:
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2005 Microsoft Corp.

Successfully created shadow copy for 'D:\'
    Shadow Copy ID: {8cca86f4-13fc-4ea4-80d7-9ccded9f14a7}
    Shadow Copy Volume Name: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1483

C:\Users\ylb>vssadmin create shadow /For=E:
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2005 Microsoft Corp.

Successfully created shadow copy for 'E:\'
    Shadow Copy ID: {f33a0652-5189-4563-9a95-c3e69ae68dd5}
    Shadow Copy Volume Name: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1484

C:\Users\ylb>vssadmin create shadow /For=C:
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2005 Microsoft Corp.

Successfully created shadow copy for 'C:\'
    Shadow Copy ID: {27c490b8-bc50-4de7-9d15-ad0f5676c437}
    Shadow Copy Volume Name: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1485

C:\Users\ylb>vssadmin create shadow /For=F:
vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
(C) Copyright 2001-2005 Microsoft Corp.

Successfully created shadow copy for 'F:\'
    Shadow Copy ID: {bf4de3e0-dbf0-422d-b08b-840e56349c32}
    Shadow Copy Volume Name: \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1490

Best Regards

Daniel

[ASHWINPAWARTESL]

Thanks Daniel. OSSVINFO clearly showed nothing wrong with the VSS writers. It seems something to do with the network (check duplex mismatch end-2-end). Anyway, keep us updated.

[paul_wolf]

OK, I'm going waaaaaaaaay out of a limb here but I had a strange situation several years ago where a copy process on the OPSSV client created an extremely deep directory heirarchy (100+ folders deep) that caused strange errors (I'm stumped if I can recall the exact error) during protection jobs.  if you have Tree Size Pro (if you don't I would HIGHLY recommend it, VERY useful program) and just check the volume. 

Total shot in the dark but maybe?

[REISTTELECOM]

Hello Together,

since we made this changes

• Set the retry count of all Volumes from 2 Servers from defazult 2 to 5
• checked with the colleague of our network team the switchport and changed the from Auto negotiate to 1Gbit fix on both the Switch and Nic

the errors haven't appeared again. Seems that both settings or maybe only one of it solved our problem. Will keep an eye on it the next two days and if they won't appear I guess the problem is solved. Will keep you informed.

Thank you two a lot for your help! Very appreciate it.

Best Regards

Daniel

[ASHWINPAWARTESL]

Thanks Daniel for the update. Good to know that error haven't appeared again. It would be interesting to know what casued it .I suggest after 2 days if errors does not occur again, try re-setting the volume retry count back to 2., just to nail down the exact cause for this issue.

Regards,

-Ash

[REISTTELECOM]

Hoi Ashwin,

I set the retry count on all Volumes back to the default of 2. Will let you know at latest in two days if the error came back!

Best Regards

Daniel

[ASHWINPAWARTESL]

Thanks for the update, Daniel.

[REISTTELECOM]

Hoi Ashwin,

had a look this morning. On one Server the errors appeared again! So, increasing the retry count solved the problem.

Best Regards

Daniel

[ASHWINPAWARTESL]

Hi Daniel,

Thanks for letting us know. These issues can be pain some time, especially when logs do not offer you much. So, finally..Increasing the re-try count resolved this issue, fantastic!

I am sure this will help lot of customers who are facing this issue.

Many thanks to Paul for providing those links.

Good luck.

Thanks,

-Ashwn