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18477
May 17th, 2011 03:00
Extremly slow migration of VMs between Qnap NAS and EMC AX150sci
Hey,
We just bought two EMC AX150SCi NAS because we weren´t happy with our QNap 809/859pro NASes. We are migrating some virtual machines from one datastore to another. They are on the same 1Gbit VLAN and migrating between the QNAP NASes we have today goes fairly quick, on virtual machine on 40GB takes an hour or so.. We are using NFS for those
The same size takes like 6h to migrate from QNAP to EMC.. EMC is using iSCSI but that shouldnt be a difference?
At another customer we experienced problems if we didnt put the NIC ports to 1000.. if we used Auto it was very slow even though it connected with 1000Mbit/S, have anyone experienced this or have a solution to the above?
Dev Mgr
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May 17th, 2011 09:00
iSCSI and NFS are massively different. iSCSI is a SAN protocol, where NFS is a NAS protocol. The difference is explained a bit here.
iSCSI needs to be on it's own VLAN or switches, completely isolated from your LAN. On the server side you need to dedicate 1 or 2 NICs for iSCSI.
If you're wanting to use both ports on the controller, you'll need to use 2 subnets for iSCSI.
FrancescoMisisc
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May 17th, 2011 09:00
Hey,
Thanks for your reply, that raises another questions i was thinking about. What is the reason to use two NICs if you cant "cluster" them? is it to use for different services? I dont see the point of having it on two subnet but I do see a point of having two nics to two different switches for redundancy.
When you say that the iSCSI need to be isolated that is only best practice right?
Best Regards
Dev Mgr
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May 17th, 2011 15:00
What do you mean with "cluster" them? Do you mean NIC teaming, or clustering 2 or more servers?
On an EMC Clarrion, it really doesn't like to have the management ports and the iSCSI ports on the same subnet (and therefor network). As you are asking about slow performance, putting your iSCSI traffic on your LAN is definitely a prime suspect for a possible cause for the slow performance.
If you're connecting a Windows server to the EMC SAN, be sure to install Powerpath, especially if you're connecting to both iSCSI ports on the array.