Poor I/O performance

[unaszplodrmann]

Is there something awry with my Joggler/Squeezeplay OS setup, or does the Joggler just perform horrendously when writing to USB storage? I'm struggling to even attain 2MB/s.

I have a PC Engines ALIX 2C3 which does routing and file serving duties at home, which limits me to fast ethernet. Having recently switched to an 80/20 VDSL service, I bought a gigabit switch and put it between my ALIX and the rest of my wired network in order to avoid potential bottlenecks. The plan was to relocate file serving duties to the Joggler, but tests with both flash media (Voyager GT) and a hard disk yielded terribad results. If someone could confirm that this is par for the course, I'd be grateful

[unaszplodrmann]

Ah no, scratch that. It seems the USB I/O fixup in Buzz's distributions is not included with Squeezeplay OS. Right then, time for some debootstrap fun. Thanks for the overlays, Buzz - fantastic stuff!

[Juggler]

Hi

I hope things go well for what you want to do - sounds very interesting.

Would you be able to let us know how it goes and write a few details on what you have done so that someone else could have a go at what your doing now ? Not really sure what is involved in what your about to do, so if I've asked for a great deal, I apologise in advance.

I haven't used SqueezeplayOS. My interest in it is as a small 'base' OS for the Joggler. I am using BuZz's Ubuntu base, which is fantastic. I'd like to have a play with SqPOS (right abbreviation?) as it can be installed on the internal flash ?

[roobarb!]

Ah no, scratch that. It seems the USB I/O fixup in Buzz's distributions is not included with Squeezeplay OS. Right then, time for some debootstrap fun. Thanks for the overlays, Buzz - fantastic stuff!

Ooh, have I missed something recent? Point me at the USB I/O fix and I'll make sure I get it in the next version. Can't be having that!

[BuZz]

I'm not aware of any USB I/O fix

[unaszplodrmann]

@Juggler

I've not made much progress with bootstrapping yet. As fas as I'm aware, BuZz hasn't made a kernel 3.2.32 package available, so I decided to go ahead and use his base distro instead. Having to build a kernel package myself would've turned what was to be a quick debootstap into a more time consuming process, so I used the base distro and just removed some of the stuff pulled in by the ubuntu-standard meta package, including irq-balance.

NFS performance was still very lacklustre with the HGST Touro portable HDD (basically a 2.5" 5k1000 in a box). I switched to the cfq scheduler by adding 'elevator=cfq' to the kernel command line in grub.cfg. Next, I removed the vendor r8168 ethernet module and un-blacklisted the standard r8169 module. This yielded a little more throughput, but more importantly, allowed for jumbo frames. The r8168B in this particular Joggler supports 4K frames, but the vendor driver would lock up if I tried to set an mtu above 1500. With this setup, I'm seeing about 20MB/s TX and 15MB/s RX from the Joggler - not great, but better.

@roobarb!/BuZz

I was referring to this:

Improved performance during USB io using a userspace alternative to a 200 line kernel patch that has been in the news recently

But then I couldn't find anything in the overlay, presumably the fixup was only used for Maverick (?)... Given that SqpOS uses the same kernel, there must be some change in userspace between Lucid and Precise that accounts for it... somewhere. When I tested file I/O with the same Touro drive under SqpOS installed on the Joggler's eMMC, the performance was shocking...

[roobarb!]

Oh, I remember that. I'm pretty sure it's included in sqpOS, or at least it should be. I need to fix up my Joggler build system, so will take a look once I've done that.