Hello, 

  Re: Bonding.  No. EQL SANs like almost all iSCSI SANs do not support LACP/TRUNKING/BONDING/MLAG, etc..  Instead, at each host, iSCSI MPIO is configured.  Depending on the OS there may be some specifics steps needed to work with the single IP subnet the EQL SANs were designed for.  Other vendors and models use multiple IP subnets. 

  There DOES need to be an interswitch link between the switches.  The EQL SAN will use any interface on a member to reach any server.   In your specific case there is only one 10GbE interface.  Other models have more than one, and or if in the future you add more EQL SANs to that group the ISL is critical.   So yes, 2x 10GbE links would be needed for performance and redundancy. 

 Regards, 

Don

#iworkfordell

I forgot to mention that my switches are 2x Mikrotik CRS317-1G-16S+RM configured via MLAG.

Looking at this article, 8.2 page 37 I think I need to create a mlag on the 2x 10G ports but I am not 100% sure

Hi Don,

I use XCP-ng managed via axen Orchestra. In xen Orchestra there is a setting to enable MPIO that I think should do the job. The 4 hypervisor all have 2x 10g port in bond lacp. The storage traverse over the storage Vlan. Everything goes through the mikrotik switches.

Thank you for the link you posted, I'll take a good look at them.

Regards 

Hello, 

 XCP-NG uses the same iSCSI initiator and MPIO as Citrix.  Just enabling MPIO will not work.  The default configuration assumes seperate IP subnets.  Allowing standard Linux IP networking to discovery both paths.  Which provides the MPIO layer the sub devices needs to create the MPIO device.  And apply the policy to balance IO. 

 With a single subnet IP you need to specifically tell the iSCSI initiator that run discovery out each port. It then creates a node file for that NIC and device.  It repeats it for every port you specify.  That also means you need multiple storage networks defined in XCP-NG  

  Regards, 

Don 

#iworkfordell 

Thank you very much for taking the time to reply. I'm glad I don't need to set any bonding. Last question, is it possible to have both module running at the same time as active active? In my test, only one 10g interface is active at a time not both. If the system is only capable of active/passive, do I still set xen server as multi path iscsi?

Thank you 

Hi Don,

I really appreciated the time you gave me and providing very clear explanations. I will experiments with it all based on what you said.

Thanks you very much

Fred

Hi,

The XCP-ng host only have 2x 10g ports. In XCP-ng, the 2x port are in an LACP active/active mode. So when you said  

"That also means you need multiple storage networks defined in XCP-NG"

Does it still apply in my scenario? The storage Vlan uses the bond as parent.

Fred 

Hello, 

 In that case I don't think you can configure MPIO.  You should have dedicated NICs for iSCSI.  I have neveer tried creating storage networks that were also part of a bond. 

  EQL doen't support VLAN tagging for normal iSCSI traffic.  

 If you just using bonding at the server level you won't get active / active I/O but at least you will have redundancy.  

 In this configuration that likely won't hurt your performance as there is only one 10GbE port on the array. 

  Regards, 

Don 

#iworkfordell

Hello Fred, 

 Thank you for the kind words.  I am so happy that I could help out.  I like XenServer / XCP a lot.  I wrote the PDF and helped write the kb article.  

  I switched to Proxmox at home, but for years I ran a XenServer farm for testing and customer support. 

  What is the firmware on that EQL array?   I would strongly suggest RAID6 as the only RAID level to use. 

  Since you can't use standard or OEM drives, you might want to try to find some EQL qualified drives to have on hand.  

 The 6110 is older, so I am presuming you don't have a support contract with Dell on that array? 

  Regards, 

Don

#iworkfordell