06-15-2017 08:49 AM - edited 06-15-2017 09:03 AM
We have two backup servers.
They both have dual fiber channel cards.
One has 3 quantum i40 librarys connected to a Cisco 4Gbps fiber switch that connects to the tape libraries.
The other has dual fiber channel cards thats connects driectly into a single Quantum i40.
On the fast server were getting up at 4,000MB/sec. most the servers get around 2000-3000 MB/sec.
The slow server were getting around 1200-1500MB/sec for most servers.
Besides for sharing a fiber switch, the fast server has its tape drives listed under Tape drives in device manager and the slow server they all show up as unknown devices however I do believe are using Vertias drivers.
The slow server was recently upgraded to backup 16 which didn't help with speeds. The fast server is running 15. Everything else is the same. They are all pulling its data from the same EMC San.
06-15-2017 10:27 AM
Do all libraries have the same tape drive (brand & generation)?
You apparently mentioned both servers and pulling the data from and EMC? Can you clarify?
The key to any performance question is comparing apples to apples. or investigating and changing only one thing at a time to see where the bottleneck is.
06-15-2017 10:44 AM
We have four Quantum Scalar i40's tape libaries, so yes they are all the same.
What I meant is the two backup servers all have the same backup source, an EMC SAN but we are performing VMware snapshot backups.
06-15-2017 10:55 AM
The tape library has almost nothing to do with performance, other than the tape loading speed (ie speed of the picker arm). What tape drives are in you rlibraries? different brands and generations of tape drives have different performance. Assuming the same tape drives and the same server OS, then device manager should look the same for both.
I would move one VM from the "fast" backup server to the "slow" backup server and see if the performance changes. That will give you clues where to look next.