We use the same libraries though we’ve not yet started to heavily load the LTO4s.   We use point-to-point for the links from the IO blades in the library to the SAN (also Brocade).  I’ve not seen them go away.

 

Things worth checking – drive firmware (though I assume you’ve seen from the library RAS log that the drives don’t drop off the IO blade) ; library firmware; switch error log and port error counts; what is written in /var/adm/messages.

 

32 drives is a lot – way more than I’d expect a 5240 to be capable of driving – I doubt it can drive even 16.  Have you checked with Symantec what they think is the right CPU power for an LTO4, and I guess the GbE/10GbE that is delivering the data?  We are using just 4 LTO4s on each T5220 we have, so that might be 8 on a T5240 – though the T5240 does not have the 10GbE on-chip.

 

Once the SAN connection is up whether it is loop or point-to-point, auto-negotiated or locked at 4Gb/s should make no difference.

 

Also consider how many LTO4s you have per FC port on the T5240s – I guess you will have quite a few if you plan to stream that many drives.   I guess the drive could run out of something if you had too many on a single port, but I’m not sure.  I think there is driver tracing available but unless you can easily recreate the problem I think that would kill your server.

 

 

 

We have configured a new environment consisting of one SUN master as the control host, and two SUN media servers sharing 32 LTO-4 drives. Each server is a T5240 running Solaris 10.  The library is a new Quantum i2000 with a single partition.

 

The FC ports on the library can be set to Loop, Loop Preferred, or Point-to-Point.  We have them set to Point-to-Point.  One of the Quantum techs suggested Loop Preferred may work better, although an EMC tech suggested Point-to-Point.  The switches are Brocade 5300 and are set to auto negotiate.

 

After 4 days of testing, we notice that drives just disappear on the media servers at random times.  We have made no changes since the initial setup, and can't understand why they just go away.

 

Any suggestions are much appreciated.

 

Regards,

 

Tom Tschida

Boston Scientific

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