best performance recomandation iSCSI vs NFS

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best performance recomandation iSCSI vs NFS

Postby ceoby » Tue Oct 20, 2015 3:31 pm

Hi all,
After I've reed some documentation I didn't understand which is the best way to use Synology and VMware. In a few words which is the best performance iSCSI block level or NFS + VAAI? We need to consider, cloning, copying, snapshots, etc. all the goodies from VMware and supported storage vendors.
I have DS 213+ for my home lab.
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Re: best performance recomandation iSCSI vs NFS

Postby funky81 » Tue Oct 27, 2015 8:37 pm

I'm interested with these answer too. All I know is that iSCSI mode can use primitives VAAI without any plugins while NFS, you have to install the plugin first.
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Re: best performance recomandation iSCSI vs NFS

Postby cowprince » Mon Dec 19, 2016 12:28 am

I as well. I'm familiar with iSCSI SAN and VMware through work, but the Synology in my home lab is a little different than the Nimble Storage SAN we have in the office :P

I've had a RS2416+ in place for my home lab for awhile. I've just not been using it for ESXi datastores at this point.

With NFS I see network utilization cap out around 115MB/s when I create a new 50Gig VMDK on the NFS volume, it only uses a single NIC.
I'm using the VAAI plug-in.
I'm using ESXi 6 with 2 NICs dedicated for the storage network that are teamed active/active. (I tried the iSCSI MPIO setup with NFS also in VMware with the whole active/unused deal that I'm more familiar with, but that didn't help the cause)
I'm not sure if I'm doing the teaming wrong for NFS or what, but I would expect to see some sort of load balancing between the two NICs on the VMware side unless it's a single threaded process?

It takes roughly 4-5min per 25gig to provision the VMDK over NFS from what I've seen so far.
Now I have also tried the file level option (I won't be able to do block level) for iSCSI using VMware Round Robin load balancing with MPIO. Provisioning a VM is SUBSTANTIALLY faster this way, couple seconds max, and no network utilization, but that's I think more the nature of the beast than anything else and of course this has nothing to do with actual VM performance once running though, just an observation.

Unless I can find out definitively that I'm doing something wrong for the NFS side or if just provisioning storage isn't multi threaded, I may have to stick to local storage only on the ESXi host I have.
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Re: best performance recomandation iSCSI vs NFS

Postby majinbelail » Fri Jan 13, 2017 4:33 pm

Hi cowprince,

You can't do load balancing when using NFSv3. If you have 2 NIC yxou can do it for failover if one NIC dies. You can do some load balancing if you have different IPs to different NFS export like and Also you can do LACP to two different NFS datastores. But as I said there is nothing compared to MPIO on iSCSI. The cap you see is the limit of 1Gbit link.

Even if you use VAAI-NAS and using Full File Copy. With that you have only the benefit if you do cold cloning. If the VM is running it's using the software datamover (FS3DM software). Even if it's powered off it's significant slower (minutes compared to seconds with block) because it's not VAAI primitive Full Copy (XCOPY) which knows which blocks to move. In the case of NFS vSphere doesn't know the file layout of the VMDK because it'S only a file on NFS.


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