Syed Jahanzaib Personal Blog to Share Knowledge !

January 11, 2021

Cisco 10G Switch & Lenovo SFP Module Compatibility issue

Filed under: Cisco Related — Tags: , , , , — Syed Jahanzaib / Pinochio~:) @ 11:46 AM

Recently we acquired cisco 10g SFP+ switch to be added in existing stack. While trying to connect Lenovo ThinkSystem SR650 (P.No: 7X06CTO1WW ) server along with lenovo provide SFP+ modules (P.No 46C3447) with 10g Cisco switch (WS-C3850-24XS-S) via MM Fiber cable. Upon SFP+ module insertion, at both end (server to switch) then the port gets shuts with err-disabled with following error on switch logs

010834: Jan 4 09:43:44: %GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port Te1/0/7 has bad crc
010836: Jan 4 09:43:44: %PM-4-ERR_DISABLE: gbic-invalid error detected on Te1/0/7, putting Te1/0/7 in err-disable state

& on vmware esxi  , it showed *DISCONNECTED*

Following were technical details:


  • ThinkSystem SR650 (P.No: 7X06CTO1WW )
  • 10g NIC: Emulex VFA5.2 2×10 GbE SFP+ PCIe Adapter (P.No: AT7S )
  • 10g SFP+ Module: Lenovo SFP 10gbase-sr Fiber Optic Transceiver Module (P.No 46C3447 / )


  • SWITCH MODEL : Cisco 10g SFP+ switch (P.No: WS-C3850-24XS-S )
  • Cisco Switch 10GBASE Fiber Optic SFP 10G Transceiver Module: Cisco SFP-10G-SR * Part No: 10-2415-03)
  • Vivanco Optical Fiber Patch Cord: LC-LC MM DUPLEX OM3 10M


After searching here & there, I found that we have to disable SFP compatibility check in the switch using below CMD’s

Add these two commands (blue highlighted) to the switch:

Switch(config)# service unsupported-transceiver
— you will get a warning message here—
Switch(config)# no errdisable detect cause gbic-invalid

Afterwards , shut/no shut the switch interface then plugged in the Lenovo cable back in.  & the connectivity got OK. (make sure WRITE the config on switch so that it stays permanent.

Note: Any time non-Cisco optics are going to be plugged in to a Cisco switch it’s worth adding these commands.

Syed Jahanzaib

Vmware VCenter inaccessible Datastore

Filed under: VMware Related — Tags: , , — Syed Jahanzaib / Pinochio~:) @ 11:03 AM

Recently one of our VCenter 6.7 got crashed & services were not accessible, I spent hours but couldn’t restore it. To save time in further troubleshooting we removed the VC from the esxi server . Few Esxi servers were managed by this Vcenter. I logged in to each ESXI  server & in Actions I selected “Disconnect it from Vcenter“. Afterwards when new Vcenter (VCSA-7) got installed , all esxi were added successfully , But one of the ESXI server was showing some errors, therefore I removed it from the Vcenter, & when I tried to add it again to VC , following error appeared

Datastore ‘M5-11.10–8TB-raid10’ conflicts with an existing datastore in the datacenter that has the same URL (ds:///vmfs/volumes/5d810e33-e56c55bf-71be-0894ef440178/), but is backed by different physical storage.

At VCenter I was seeing below

When I right clicked on this data store, DELETE/MOUNT/UNMOUNT option were greyed out as well. How can I remove this inaccessible data store?

From the Vcenter, I Browsed that inaccessible datastore  , & clicked on VMs tab, it was showing one VM which was moved to another esxi host in the past, I edited that old VM on that esxi server , and removed the mounted ISO (which was pointing to the affected vm esxi server)  , afterwards, the inaccessible datastore disappeared automagically, and the Esxi got re-added in VC again smoothly.

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Syed Jahanzaib

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