I/O performance issue FreeNAS 8.3

[jango]

Hi all,

I'm using freenas 8.3 and i have performance issues.
My network structure :

cpu i-3 - 4 cores
RAM - 16 GB
freenas with raid z - zfs
1 WD - system
3 WD red X 2TB - for data

I've created multiple volumes,every volume use for iscsi that connect to windows server.
1 volume connect for roaming profile share(something like 40 on the same time).
1 for shares.
1 for VM storage.

and now the problem ....

when i try to backup files (share to the iscsi volume) the i/o getting realy bad and users even cannot login to the computer.

on the freenas server i get

time to read 10MB block 7.489819 sec .

any ideas?

Thank you very much.

 

[jango]

MayB some can tell me if it's really I/o issue or it's Because to much data pass through there?

 

[draetheus]

How many users are connecting at the same time? Consumer WD drives are not meant for concurrent multi user operations at all to my knowledge. That's what SAS drives are for. Also if your drives are configured in a RAIDZ, that's going to be much more costly than a Mirror + Stripe configuration. Especially for an i3 (which is dual core, not quad core as you listed).

 

[cyberjock]

iscsi isn't always fast. Plenty of threads of people complaining. Generally, if you want high speeds from iSCSI it means lots of RAM and an L2ARC. I will tell you that if you have 40 roaming profiles you can expect alot of random reads and writes from all those users and that's going to keep your pool very very busy.

If you have a disk failing in your pool it can cause performance to be very very poor.

But the little bit of info you've provided gives no indication of what is wrong. It's analagous to "my car doesn't drive fast". There's plenty of reasons, but you'll have to start ruling them out one by one until you can narrow down a subsystem or find a bottleneck somewhere.

 

[jango]

Thanks for the reply.
The average users at the same time is something like 40/50.
There are some i3 with quad.

 

[jango]

The users use IMAP that stored on the freenas .
Its in this deployment cause I won't let them sync 10 GB every login.
There is lots of data read/write.
I just want to know there is solution for my issue...?
More ram? Change to raid 1 would be better? How to deploy it currectly?

 

[cyberjock]

I'd try more RAM first. Doing several vdevs in mirrors would be helpful if disk I/O is very high. ZFS caches stuff in RAM which also helps I/O. Honestly, I'd have gone with 32GB of RAM to start for 40+ users. What CPU in particular do you have?

 

[jango]

He he sorry I was wrong i3 2 cores I'll start by change it to I7