VMware vSphere

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  • 1.  iSCSI software adapter vs iSCSI HBA

    Posted Nov 12, 2011 07:19 AM

    I am probably answering my own question here by just stating it in the title.  I am setting up a fileserver on esxi and I have read in some places that going directly to the Windows server is best or a good way of servicing up the LUNs from the SAN.  And in other readings I have seen it as let esxi deal with it.

    its a 2 part multiple questions.

    -let esxi or windows handle iscsi?

    -and if I am letting esxi serve then should I be using the iscsi software adapter or the iscsi HBA.  and I am already leaning towards the iscsi HBA just by the fact it is more secure and it can give a higher performance.

    -and lastly what I am not understanding what is multipathing (i get that it's multiple physical paths to a storage)  and how the routing should be setup.  there are 4 iscsi adapters shown but the same one repeated twice.  so its only 2. (see attached pic; 0&1 have the same iqn and 2&3 have the same iqn). so how will a host failover work? will it cause all routes to be disabled? or will it failover to another host? And is there a limit on the LUN size that i can serve to a path?

    I apologize for all the newbie questions. I am just trying to wrap my head around things and confirm my readings.  Thank you. appreciate the time.



  • 2.  RE: iSCSI software adapter vs iSCSI HBA

    Posted Nov 12, 2011 08:53 AM

    goof1427 wrote:

    -let esxi or windows handle iscsi?

    I think it has several benefits of having ESXi handling the iSCSI connection: you do a greater amount of virtualization and the guest does not need to know that it is accessing the disk through iSCSI. This means you could later move the actual storage from the vSphere side without having to do any re configuration of the guests. It could also improve security by not letting the guests accessing the storage network at all.

    goof1427 wrote:

    -and if I am letting esxi serve then should I be using the iscsi software adapter or the iscsi HBA.  and I am already leaning towards the iscsi HBA just by the fact it is more secure and it can give a higher performance.

    If you already have installed adapters with hardware iSCSI support then it would be better to use them, as it will reduce some CPU load from the host.



  • 3.  RE: iSCSI software adapter vs iSCSI HBA

    Posted Nov 12, 2011 10:21 AM

    Hi goof1427

    if you have Broadcom HBA then you use Software iSCSI Initiator rather

    Look here: http://www.vmadmin.co.uk/vmware/35-esxserver/252-esxihwswiscsijumbo