#AFF C250 and HPE DAC 10G SFP+ cable

1 messages · Page 1 of 1 (latest)

slate drift
#

Hi, my colleagues were installing on remote site AFF C250 but there were no transcievers for HPE 5700 iscsi switch. They found dedicated cables HPE FlexNetwork X240 10G SFP+ to SFP+ 3-m Direct Attach Copper Cable JD097C and plugged it in HPE5700 and C250. It lit green and negotiated 10G. I could not find this cable on HWU but NetApp is not throwing any errors. Links are staying up, they will be for iSCSI. I think it will be ok if there are no errors? Or should we look into other options?

mortal grove
#

Can't tell for sure. You might be lucky but I would still suggest monitoring the ports, especially the error counters.
We have seen systems in the past with unsupported SFPs that seemed to work fine at first (link went up), but as soon as lots of traffic was involved they started throwing heavy crc errors to the point of making them unusable

uneven hinge
#

I know the Netapp branded and “Cisco coded” twinax/DAC cables work fine. Due to the way twinax works, most twinax usually works fine as long as it’s passive. The AOC cables are not supported (at least 10g on all platforms. A couple platforms support aoc at 100g). In this situation I would still look at getting supported optics (even third party ones that meet specs) and fiber to be safe. My customers with Juniper and Arista switches do this

slate drift
#

Yeah it seems that we are lucky but will monitor. So far no errors. Also I've checked other Netapp on this site and it does have 2650 with same cable - few houndred days of uptime with 0 errors and also iSCSI for VMware there.

slate drift
#

@mortal grove @uneven hinge we'll get supported transcievers for switch but its 10G max. AFAIK if transciever in NetApp will be 25G and one in switch 10GB it should work. It will just scale down from 25G to 10G on netapp side.

uneven hinge
#

It will not work. The supported Netapp optics are either 10g or 25g and not auto ranging

slate drift
uneven hinge
#

I believe that to be true

#

If it does link, it will be an unsupported configuration

mortal grove
#

yeah that won't work, one SFP would talk much faster than the other, there's no way those could understand each other 🙂

uneven hinge
#

FWIW, e-series does have Supported 10/25 optic. Just not supported with ONTAP

mortal grove
#

in contrast to FC, Ethernet SFPs usually do not autonegotiate speed (there are some that do, but all those that are supported by NetApp in ONTAP systems don't)

slate drift
#

so we will stick to DAC cables for now, performance is superb and no retransmission errors for now

#

next we will replace 10gb switch to 25gb one

mortal grove
uneven hinge
#

Nope. Look it up. It’s listed as a 10/25g iscsi transceiver

#

Really wish ONTAP world support it

mortal grove
#

well... that just shows how few E-Series systems we sell 😉

uneven hinge
#

lol. I am a walking talking hwu. I actually designed the very first one back in the 90s. Lots of classified sites. Only allowed to bring printed copies. Someone higher up at NetApp saw it and developed that first hardware poster

slate drift
#

ngl this one confused me, but maybe in autoranging they mean that it will scale down to 10gb transcievers if you put them in

image.png
mortal grove
uneven hinge
#

No that means if you use a 10g optic it works at 10g

mortal grove
uneven hinge
#

You don’t need to change the personality like we did for converged adapters or breakouts

#

If you use a 25g optic/cable it works at 25g

mortal grove
uneven hinge
#

Odd it’s not listed in hwu. I think in the quoted it shows differently. I think it’s the x6606 25g. When you pull it out of the system it clearly says 10/25g on the transceiver! Very odd. I’ve seen it before in a Netapp, I just can’t place which platform. Hell, maybe it was a solid fire?