Most switches have diagnostics that allow you to look at the traffic on the

Multiple partitions backing up through one NPIV 8GB port can (and most
likely will with modern equipment) saturate that line. I'll only design a
maximum of two partitions per port, and then only one production partition
per port. Ports are cheap. Fibre Cable is cheap. Don't skimp.......

Jim Oberholtzer
Agile Technology Architects

-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxxxxxxxx> On Behalf Of Rob
Sent: Thursday, January 30, 2020 7:27 AM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxxxxxxxx>
Subject: RE: VTL - Fiber vs SAS

Just curious, but has the single 8GB FC really been maxed out? Was there
some performance tool on the switch which showed this? Disk speed from the
source and tape speed from the target were ruled out as factors?

Honest though, we never made it to LTO6 before going VTL. And our
experience with LTO5 never went into production. LTO4 was really where we

Rob Berendt
IBM Certified System Administrator - IBM i 6.1 Group Dekko Dept 1600 Mail
to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
6928N 400E
Kendallville, IN 46755

-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxxxxxxxx> On Behalf Of Holger
Sent: Thursday, January 30, 2020 8:11 AM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxxxxxxxx>
Subject: Re: VTL - Fiber vs SAS

CAUTION: This email originated from outside of the organization. Do not
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right. Then also not to forget to have the IBM i host have multiple NPIV
capable ports to gain faster speed.
It's of not much use to have one 8GBit fiber port on the host and 4 fast
LTO6 drives with one 8GBit (or faster)
port for each drive. Been there, done that ;-)

Am 30.01.2020 um 13:59 schrieb Rob Berendt <rob@xxxxxxxxx>:

One big difference between a VTL and one of those IBM 3xxx series physical
libraries with multiple drives is that the VTL uses a single port on the
NPIV capable switch even if it has multiple tape drives configured in it.
The physical library has you run a separate cable from each drive in the
library to the NPIV switch.

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