planning esx deployment: why do i have to own FC switches?

[newtoallthisstu]

Hi folks,

this is my first post, first of all sorry if whatever i could say in here is not technically "appropriate", i'm trying to evaluate by myself, as a newbie into SAN technology, what black box dell/hp/fujitsu/ibm force/want me to buy.

my deployment will be very simple. i'll have about 8 low-load non critical machines (a couple of webservers, two DCs, one mailserver, really not much traffic/performances needed here) running on two esx hosts loaded with ram.

questions here are about storage. i've spent quite some time looking at CX3-10C from emc, it seems to fit what i'm looking for, 2x 4Gb FC and 2x iSCSI on each of the two SPs.

ideally, i thought about direct FC attaching my two hosts to the CX3-10C, and having iSCSI for a couple of external server for nightly backup to disk purposes. seems like a direct attach solution is not officially supported for esx, please correct me if i'm wrong, but why on earth should i spend about €3500 x2 + 4 sfp and licenses for just two hosts? paths are already redundant for failover with 2 hbas each host crossed with fc ports on SPs!

i have absolutely no plans to add anything else on FC side, just plain run my VMs from the storage, that's all, and play with HA and DRS.

another very important question to me, as the solution estimation is still undergoing and we'll be making our choice within some weeks, could i "aggregate" two iSCSI hbas to have a 2Gbit iSCSI connection to the CX3-10C? is this called trunking and would it fallback to 1gbit in case of a path failure? found no answers so far on this, maybe just because it's unsupported..

that would be very interesting, i could even think to leave away FC and run everything iSCSI, waiting for 10GbE to become more popular

thanks for reading

Giorgio

[doubleH]

IMO for your small environment iSCSI would be a perfect fit for you. Not sure what you existing network infastructure looks like, but if it can handle iSCSI then you are good to go. There are a number of iSCSI products on the market such as EqualLogic, Lefthand. Do a search on the fourm to see how people like these and you won't even consider FC. EqualLogic has many fans (including me) in this fourm and works extremely well with vmware.

[newtoallthisstu]

doubleH, thanks for your answer.

i'm just a little bit scared about iSCSI performances and if one day that would become the bottleneck of the solution, i could go FC with a cx3-like system instead of trying to explain to the management i saved 10% going iSCSI from FC, and now they have to spend again the whole money because they had fun with virtualization and want now their kids' PCs to be virtualized too

do your EqualLogic or Lefthand solutions support trunking of 2x 1gbit? unfortunately their markets aren't so widespread here in Italy afaik, even no resellers at all for Lefthand..

btw, are you aware if direct connect solutions of storage to esx hosts with FC and iSCSI onboard actually exist and are supported?

thanks again

G.

[ngrundy]

The usual reason for getting FC switches is expandability, you may only need two physical hosts and two SP connections per switch now but down the track adding a 3rd host becomes simple, plug it in.

If you're scared about the price get your vendor to quote on a switch such as a McData 4400. It's a 16 port switch but only comes with 8 ports out of the box, you can then upgrade the switch in two 4 port increments via a software licence and SFP purchase. We just got two of them for a small 2 server project based on the excellent run we've had with the big brother 4500 series.

[CoreyIT]

Your worrying for nothing. The performance difference between iscsi and fibre in your case is going to be negligible. The only advantage you would really gain by going fibre in this case is increased bandwidth/throughput of your vm's to the san, not so much quicker speed in the general sense. you do not have enough vm's to saturate your link to the san. You are going to the speed difference in controllers, backplane, bus and spindles before noticing the difference in fibre vs. iscsi transfer speeds.

If you are contemplating any of the cx3-x models then go with the 'c' designation as they support both 4gb fibre and iscsi.

[mattjcom]

Giorgio, I went through similar issue as you, trying to decide which storage platform to go with. I evaluated the differences between iSCSI and FC and which one suited my environment better. We eventually settled on the Compellent product as it offers iSCSI and FC in the same box so we went with iSCSI to start and ended up installing FC at a later stage to handle our more needy boxes once we migrated them to VMware. We direct attached the hosts to the Compellent SAN for FC and run iSCSI over the network as we serve up storage to physcials boxes as well.

The EqualLogic is a great box as well and I am running some of them as well in other environments. We chose Compellent as we wanted the flexibility of FC and iSCSI.