iSCSI Write performance

[wabbot22]

Hi,

I´m using truenas since one year, but I´ve bad write performance and now I´ve a little bit time for troubleshooting.
Bbut let´s start with my enviroment:

Supermicro Board with Intel(R) Xeon(R) CPU E3-1240 V2 @ 3.40GHz, 32GB ECC, 2 x Fujitsu 2607 Raid Controller flashed to IT Mode,
10G SFP+ Network Adapter. Boot drive is an 120GB SSD Mirror...

My Main Pool is a 6 x 2TB NL SAS SEAGATE ST2000NMCLAR2000 ( 2 x 3HDD Raid-z).
I´ve added a 500GB SSD Mirror for SLOG´s and a 100GB SSD as an L2ARC Cache.
I´ve an vMware DATASTORE on the Pool which is connected to the ESXi via iSCSI.
It works, but I don´t get more that 500MBit/s to the datastore, which is for a 10G Network not so much.

So I´ve done a little bit troubleshooting:
- Add a new Pool with the 2 SSD´s only, then I get ~2GBit/s to the NAS. So it looks like the reason mus be at the HDD Pool.
- Disable sync write, the I get 550-600MBit/s. Also not to much speed.
- Test a Hardware with more performance. I use a Fujitsu RX200 S8 with a 8 Core XEON and 96GB RAM, same Controllers and Disks,
no difference...
- I´ve reade several hours Forums and so on, but I don´t find any idea, why the pool is so slow (It´s only during write, reading works much faster...)
- I´ve checked the native performance to the Harddisks with DD ~130-150MB -> 1,2GBit/s to one Disk.

Does any one has an idea, what I can check/change to get a better performance...?

Thanks !!!

 

[jgreco]

Welcome to the forums!

Sorry to hear you're having problems.

Please help us help you by posting detailed information about your system, especially including, but not limited to, detailed information about your network setup. The Forum Rules, helpfully linked at the top of every page in red, includes some guidance as to how to build a problem report and hardware description that is more likely to result in some useful responses.

Particularly apropos to this discussion would be an explanation of what network adapter you're using, and whether you've applied any tunables. Adapters other than the recommended Intel and Chelsio ones tend to perform more poorly. You also mention SSD's for SLOG, which can be a sticking point, though you also mention you disabled sync writes, so that's not as likely to be your problem.

 

[wabbot22]

Hi,

sorry, that I miss some informations:
- Networkadapter Intel Corporation 82599EB 10-Gigabit SFI/SFP+
- Mainboard: Supermicro MBD-X9SCL-F
- SSD´s are SAMSUNG 850
- Network Switches: CISCO 3750-X / and I´ve also tried a NEXUS 5548
- Use a dedicated VLAN for iSCSI

And yes, with disabled sync writes the performance isn´t realy better....

I hope that I don´t miss some informations again....

P.s. I´ve also checked the Esx Server with a NETAPP ~5GBit/s read and write