Performance Bottleneck - HBA Power Setting

[knewman]

Hi All! I'm pretty new to TrueNAS, I ran a tiny FreeNAS build years ago but am just getting back into the scene now.

I'm in the process of transferring my data from a diaspora of Synology hardware to a single TrueNAS Scale build. I wanted to share a scenario I ran into in the hope that it helps someone with the same problem at some point. I spent most of the day combing "performance bottleneck" search results and couldn't find anything about this as it's somewhat specific to my hardware.

During post build burn-in and initial data transfer I noted really poor speeds on my data array. I was only able to utilize around 400mbps on the gigabit connection. Internal testing to rule out network/SMB issues showed my read/write speeds were limited to 42.5 MB/s - way slow given my hardware! I used the ARCCONF utility to review the config of my Adaptec SmartHBA 2100-4i4e and finally found that the power mode had been set to "Minimum Power"

Code:

$ sudo ./arcconf GETCONFIG 1 AD

~~~~
-------------------------------------------------------------------
Power Settings                             
-------------------------------------------------------------------
   Power Consumption                          : Not Available
   Current Power Mode                         : Minimum Power
   Pending Power Mode                         : Not Applicable
   Survival Mode                              : Disabled

I used the utility to change the power mode to max perf:

Code:

$ sudo ./arcconf SETPOWER 1 POWERMODE 3

I'm now saturating the gigabit LAN link to the appliance. So it seems like the minimum power mode caps SAS transfer speeds at 42 MB/s on this HBA. Pretty simple in retrospect but took me a while to find the cause. Hope this helps someone down the line.

 

[Ericloewe]

I hate to be the bearer of bad news, but if that's the worst problem you get with Adaptec, you're extremely lucky. There's a reason anything other than LSI is warned against.

 

[knewman]

There's a reason anything other than LSI is warned against.

I'd seen the myriad of warnings in various beginner guides against straying from LSI. However I didn't see much about this specific model of HBA in my searching. Most of the stuff about Adaptec I could find seems to be about older models that are intended purely for RAID workloads. I figured this model isn't widely used OR doesn't experience many issues that induce posts.

My data isn't super critical so I'm willing to be a guinea pig. Plus it's one of the few cards that fit in my chassis and doesn't cost an arm and a leg.

 

[Ericloewe]

Guinea pigs are always welcome, of course. Let us know how it goes.

 

[ChrisRJ]

My data isn't super critical

In that case TrueNAS is a really odd choice. Why did you go for it?

 

[knewman]

In that case TrueNAS is a really odd choice

On the contrary - I think TrueNAS is the perfect choice for such a use case. I'm not sure I'd trust a community-supported software package like this with anything mission critical, something that would have any sort of financial impact in the event of downtime. But for my basement data collection I think it's a fine choice. I'd be sad if my bits all went up in smoke, so I want something robust, but really no worse off if I lost it all.

I went with TrueNAS because it seems like a mature ZFS implementation with a considerable userbase which has probably already experienced and documented most of the problems I'd encounter. Also, I've got a pile of enterprise hand-me-down equipment that I wanted to cobble together into a usable and perfomant storage array, most of which wouldn't be compatible with typical consumer storage products. TrueNAS seems to bridge that gap nicely.