Freenas iscsi and VMWare Workstation

[drfresh]

I'll try to to this as short as possible. I'm very new to iscsi and VMware, I have to say, and in general just an interested technology amateur .

My setup: HW box with 6*2TB disks running freenas 9.2.1.2. HW Box running Win7 (Core i7 4770K 3.5 GHz, 16 GB RAM, 2*240 GB SSD disks in Raid1 2*GBit/s NICs) with a 1TB "iscsi drive" attached from my FreeNas box as D:\. And I have a Synology DS1813 NAS with some 40 TB storage as well.

On my Win7 box I run a VMware Workstation 10 and have build a couple of VM's (e.g. one running Win7 and others) that have their Virtual Disc on the "iscsi disk" D:\.

In the Win7 VM I get a Windows Experience Index on my disc of 7.6. When I run a LAN Speed Test against my Synology in this Win7 (the VM) I get very good results - up to 800-900 Mbps.

BUT when I try to copy files from the Win7 VM to the Synology I get rates aound 6-7 MB/s! I see my two NICs on the Win7 HW box is only utilized below 25% on the one and below 12.5 % on te other during copying of large files from the Win7 VM to the Synology.

I just don't get it! What am I doing wrong? How should I set up a system using my freenas as the storage for my VM's?

Perhaps this is not a question for this forum but for a VMware forum - if so, please excuse me!

Thanks in advance

 

[cyberjock]

You've just been bit by the 'benchmarks don't reflect reality' bug. In short, because of how ZFS works iSCSI performance depends on a boatload of factors. To get "reasonable performance" you often need to add more RAM than you normally would.

There's tons of examples of people that have your problem or very similar. I'd suggest you search the forums because we've all pretty much stopped answering this question every 3rd day. ;)

 

[c32767a]

BUT when I try to copy files from the Win7 VM to the Synology I get rates aound 6-7 MB/s! I see my two NICs on the Win7 HW box is only utilized below 25% on the one and below 12.5 % on te other during copying of large files from the Win7 VM to the Synology.

So If I'm reading that right, its:


Frenas --- iscsi ---win7 physical box ----- VMW10 ------ win7vm ------- SMB ------ Synology NAS ?

And the copy you're getting 7MB/s on is reading data from the FreeNAS iscsi mount point, through VMware's abstraction, to a VM, then on via SMB over the network to a sinology NAS.


Lots of moving parts to troubleshoot and with VMware Workstation involved, you also have to factor in other VMs, etc.

My advice would be to break everything down into the smallest components in the path and test each one, then slowly build back up from there. There are lots of tools on the internet for testing all that stuff. If you're interested in technology, it'll be a good learning experience.. :)

This is an educated guess, (and may be completely wrong) but I'll bet you will find a bottleneck at the Synology NAS. I bet you will find another one in all of the virtualization that's happening on your Win7 box.

 

[cyberjock]

So If I'm reading that right, its:


Frenas --- iscsi ---win7 physical box ----- VMW10 ------ win7vm ------- SMB ------ Synology NAS ?

I don't think that's what he's doing. But how you have me wondering myself.. lol.

 

[toadman]

If he's running the .vmdk on Freenas I think that chain is probably right.

- The "Frenas > iscsi > win7 physical box > VMW10 > win7vm" part is accessing the .vmdk on the READ part of the copy.
- The "win7vm > SMB > Synology NAS" part would be the WRITE part of the copy.

How is the Win7 physical box networking configured since "2*GBit/s NICs" is mentioned?

Also, when you say "copy files" what does that mean? It's quite a bit different to copy 1GB+ media files into ZFS vs. directories of a bunch of small files. I get over 100 MB/s on the former and can get less than 1 MB/s at times doing the latter.

I'm not sure how the Windows experience thing actually tests disk performance. In your tests there isn't really anything that says how fast your iscsi disk goes. What performance do you get inside the VM if you copy those same files from one directory to another on the .vmdk? (or onto another .vmdk you attach if you don't have space on the first one.)

 

[c32767a]

- The "Frenas > iscsi > win7 physical box > VMW10 > win7vm" part is accessing the .vmdk on the READ part of the copy.
- The "win7vm > SMB > Synology NAS" part would be the WRITE part of the copy.

David Wheeler said it best.. :)

"Any problem in computer science can be solved with another level of indirection."
"Except for the problem of too many layers of indirection."

 

[toadman]

David Wheeler said it best.. :)

"Any problem in computer science can be solved with another level of indirection."
"Except for the problem of too many layers of indirection."

Indeed. And it's worse than diagrammed above too as the WRITE part has more layers. :)