iSCSI Software Adapter

[uinthas]

I have have been experimenting using iSCSI target for my virtual environment.  So today I created a iSCSI target on a 2008r2 box, connected it to vsphere client iSCSI software adapter and then added the storage, everything worked fine however it is worse then slow. Essentially I can create a fold it the new storage and thats about it, when I try to move a large file like an ISO I get I/O error and it dies, write latency is 78884ms read 3021ms.   I unmounted it and attached it to my windows 7 machine, all was great was able to transfer files back and for just fine.  Both the vspher network and 2008r2 box are on a 1G port, I have not configured a second virtual adapter on vshpere at this point because i am just testing, any recommendations or areas that I can look for a problem?

[tomtom901]

How is the latency (ping) normally between these hosts, and did you encounter any problems while adding the target?

[YiLing98]

Hi

Welcome to the communities.

Please run below command.

To disable delayed_ack, run this command from the command line:

vmkiscsi-tool -W -a delayed_ack=0 -j vmhbaXX

To enable delayed_ack, run this command:

vmkiscsi-tool -W -a delayed_ack=1 -j vmhbaXX

To check this parameter, run this command:

vmkiscsi-tool -W vmhbaXX

If I have lost confidence in myself, I have the universe against me.

[admin]

To achieve higher performance we recommend to use Round Robin policy in iSCSI initiator. By default ESX(i) uses FixedPath policy. You can change it to RR by choosing "Manage path" option in properties of datastore or target (can be found in "Datastore" or "Storage devices" menu).

Either by default ESX(i) switches to another path every 1000 IOPS. To improve bandwidth and performance you can change this value to lower. You can do it following way:

Connect to ESX(i) with SSH or open local console, and type in

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esxcli nmp roundrobin setconfig --device [UUID] --iops 1 --type iops

or

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esxcli storage nmp psp roundrobin deviceconfig set -d naa.хххх -t iops -I 1

UUID of device you can found in "Storage adapters", while amount of IOPS 1 is the best recommended option. You can check properties of your device with following command:

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esxcli nmp roundrobin getconfig --device [UUID]