within NetWorker 6.1.3 many I/O errors on IBM LTO-2 drives

[hdvries]

Almost one year ago we installed a STK L700 library with IBM LTO-2 drives attached to our Legato NetWorker server on AIX. Library and all tapedrives are independently attached to the server and to several storagenodes using SAN connections.
From the beginning we suffer all kinds of problems in this environment, such as I/O errors, Connection timeouts, tapes which are not unloaded etc. We put a lot of effort in trying to solve these problems. We installed the highest level of firmware and drivers in the LTO drives, SAN (Brocade) switches and in AIX. Most of the problems disappeared, but we are still suffering I/O errors. During backup writing an I/O error occurs, the tape is set to "full" by NetWorker and the backup continues with another tape. It happens on different storagenodes (all AIX), but not on the server. It also happens on all available devices in the STK library. In the errpt of the AIX system we see no errors at all. Any suggestions ???

 

[Serbtastic]

I suggest you get the hardware vendor on site to have a look for problems with the hardware.

The I/O errors are not generated by Networker, only reported by it.

Also, Networker marks the tape as full, and continues with another tape so that you are not writing good data to a possibly bad tape.

 

[hdvries]

Of course we already invited STK to this customer site. They did extensive tests on the tapedrives and the library, with no results at all. Some drives were exchanged, but also on the new drives we got the same problems. We are almost sure it is not a drive problem, but maybe something in the SAN environment.

 

[Serbtastic]

Then have your SAN architect run extensive tests, and ensure its configured correctly. Again, Legato Networker does not GENERATE these errors, only acts upon them when the OS reports them.

 

[pbht174]

You can chante the timers in autochanger setup.(in Networker interface).

 

[joser01]

Have you installed the IBM LTO2 Drivers? I am facing a similiar problem (but on Solaris). I am using the native Solaris drivers, and have been told by a consultant that I need to use the IBM LTO2 Solaris drivers.

 

[Pachtva]

I have the same problem but the servers are AIX with L80 and tape drives Seagate Lto Gen 1.. STK review all the hardware and it works fine.

IBM sais that thier HBA its fine.. then ... where is the problem.. i bealive that is some patch or misconfiguration in the SAN

 

[meyer8458]

joser01, Did your problems on Solaris resolve after installing the IBM drivers? I am using the native st driver on Solaris and I am having similiar issues. I have tried multiple configurations in the st.conf as well as using the native st driver. I am running Solaris 8 if anyone knows the best st.conf setting for these tape drives please let me know.

 

[joser01]

Meyer8458,

I did install the drivers. No problems. I was working at another site that also had IBM drivers, but guess what? They exhibited the same problem!!

I have spoken with Legato Support - they told me that they have had problems reported with both the IBM and the native drivers.

So, at this point, I am also back to the same point as the original poster. Interestingly, my original site has not had problems since the IBM drivers were installed.

Both sites have STK L700 libraries and the most current firmware is installed.

Different SAN hardware though.