I own 3 esx servers 4, connected to a NetApp 2020th cabin, dual controller active / active. Each controller has 2 interfaces (e0a and e0b) NetApp reading the documentation, have two connection options: Using LACP, or by using standard software interfaces with the MPIO iscsi vmware, creating 2 or more vmkernel ports.
I opted to use the second option, spending 2 physical cards in each server to connect esx iscsi. I created a vSwitch for iSCSI, with 2 vmkernel port.
without using an adapter in each case. ( Unused Adapter option).
On the side of the cabin, I configured the interface of each controller e0a with e0a interface of the other controller as its partnet, plus you have assigned a second IP address as an alias. So that I have e0a controller "A", with IP 192.168.1.17 and 192.168.1.40 alias; e0b controller "A" withIP 192.168.2.17 and 192.168.2.40 alias; e0a controller "B "IP 192.168.1.18 with and without alias e0b controller" B "with IP 192.168.2.18, and without alias.
Now, in the iscsi initiator configuration vmware , add only the "Dynamic discovery" IP 192.168.1.17, and I appear on the tab "static discovery", the four IP addresses.
Once you add this, each datastore I get with 4 paths available.:
Is this a correct configuration? ... be improved ?.... If I add more IP addresses "alias", the "paths" multiply, also happens if I add more vmkernel vswitch port to ....
Doing this in ESX 3 servers, not "overload" the connections of the cab ?....As I can see if packets are being dropped? ... I have the possibility of adding to each esx server 2 more cards for iscsi vsiwtch of adding 2 to each server vmkernel port .... good idea or not ?....
Looks ok and seems to be inline with the best practices. Have you also enabled the vmhba to load balance traffic accross the iscsi adapter in the esx server this way it will distribute the load accross each vmkernel port rather than only one inbound:
esxcli --server hostname swiscsi nic add -n vmk1 -d vmhbaxx
esxcli --server hostname swiscsi nic add -n vmk2 -d vmhbaxx
esxcli --server hostname swiscsi nic list --adapter vmhbaxx
The behaviour is expected if you add additional ip alias on the netapp vif as the esx will see this as another interface this goes for the vm kernel ports too. Adding more vmkernel ports will only be required if aggrgate bandwidth is increases.
Do a cf takover an giveback and make sure the paths are still active during that process.
I think you will want to watch CPU utilization and latency closer than bandwidth in this set up.Running switches, especially gig or 10gig in software can put a lot of load on a general purpose CPU. The same is true on the filer side since a 2xxx series box does not have the same horsepower as some of the bigger systems. Not that it will be your bottleneck but it's certainly something to watch.
But #1 stat in my opinion is the latency for disk access. Watching this on your VMs as well as on the filer itself will give you a great idea of what's going on in the storage subsystem as a whole.
I continuewith myperformance tests....andI do not understandthe following:
In avmwaredocumentstates: "" When You SetupmultipathingiSCSIHBAsandBetween Twomultipleportson aNetAppstoragesystem,givethetwoHBAsorstaticdiscoveryDifferentdynamicaddressestoconnect tothestorage. TheNetAppStorage SystemPermitsonlyoneconnectionfor each 'Each targetandinitiator. Attemptstomakeadditionalconnectionscausethefirstconnectiontodrop.
On the otherhand, thefas2020,I setthe parameter "iscsi.max_conneections_per_session" to 32 (the maximum), and instead, the command iscsi show -p iscsisessiontells methat in eachsessionthe"maxconnection"is 1
Also, if yougenerate loadin the cabin, the sessioniscsi-v commandshows methe messageagain and again"Seq/ xxx".....Scsidb_RD_WaitingBurst
Is all thisnormal?or I have tosetsomeadditional parameters? ...
I can nothave awindows machineto connect anddo the tests....ButI madethe following test:
Fromthe same ESX server,and with the samevswitch/vmkernel, Iconnected to LUN 1 of controller"A"of theFAS2020. Then, i runthe following command to createa heavy loadin the cabin ( time vmkfstools -c 12G -d eagerzeroedthick test.vmk ).The resultis thegraph1.
Then, Iconnected to anotherLUN (2) ofthe same controller, with the sameresult of the gragh 1.
But then, I haveconnected to other LUN (3) of the other controller "B" ( the fas2020 is model active/active),and the resultwas multiplied by2.Graph 2.
In both cases theCPUis at 100%....maybe thatthe reason?....