Performance and reliability issues.. with an odd hardware setup

Not open for further replies.


Nov 27, 2011

I am completely new to FreeNAS (and mostly new to BSD) and I've got a perticularly odd problem to pin down.

System :
FreeNAS-8.0.2-RELEASE-amd64 (8288)
Intel Atom D525 1.8Ghz Dual Core
4GB DDR3 (7-7-7-24)
Intel NM10 Express chipset
6 x USB 2.0
1 x Mushkin 8GB SDHC (class 10) <--- THIS IS THE BOOT DRIVE
1 x A-Data 30GB SSD (internal Sata2) <-- Currently setup as cache for ZFS via web-interface

Mediasonic (HF2-SU2S2) 4 Bay Sata enclosure, connected via USB (unfortunately I can only see 1 drive if I use the esata port due to Zotac's 2 port sata controller).
3 x 1 TB WD Black 7200rpm HDD
1 x 1 TB Hitachi Deskstar 7200rpm HDD

I've setup my share with all 4 drives combined into a RAIDZ2 configuration and setting my internal SSD drive with the cache option.

The problem I'm getting is transfer speeds. Now I realize I won't get anywhere near max being that my primary drive source is connected with USB 2.0.

If I setup a CIFS share, and copy a 2GB file from my main pc (copying FROM an SSD) to the CIFS share, it starts off at about 25-35MB/s, however it very quickly drops to 8-11MB/s throughput.

If I then setup an iSCSI drive and connect with that, I get MUCH better speeds...
burst speeds as high as 110MB/s and an average of 48-52MB/s (something I would more expect), and it sustains this for most of the copy... however the last 10% of ANY sized file I suddenly drops again, and then I start to get ISCSI errors on FreeNAS.

Nov 27 21:06:32 STORAGE root: ZFS: zpool I/O failure, zpool=storage error=6
Nov 27 21:06:32 STORAGE last message repeated 494 times
Nov 27 21:06:32 STORAGE root: ZFS: zpool I/O failure, zpool=storage error=28
Nov 27 21:06:37 STORAGE last message repeated 998 times
Nov 27 21:06:37 STORAGE root: ZFS: vdev I/O failure, zpool=storage path= offset= size= error=

At which point I have to completely disconnect the ISCSI drive from my windows box and the reconnect for me to be able to read/write from the iSCSI drive at all.

I have set the following via /boot/loader.conf


however this has had no real effect, and I have gone as far as creating an network interface and setting the options to "MTU 9000 up". I confirm that my MTU is set to 9000 using ifconfig.

Can somebody tell my how / where I can troubleshoot these different issues. I don't much care if I use CIFS or iSCSI, but I'd really like higher performance or reliability than what I'm achieving at the moment.

Any help / pointers are apreciated and welcome...

Thanks in advance,

Not open for further replies.