Re: USB stick access freezing up system?

googlegroups@xxxxxxxxxxxxxxxx wrote:
I'll explain a little about my application... for each object it
examines it needs to check refererences to see whether to add further
ones, which in some cases means 2000+ key searches of the db per
object. As you can imagine the HD goes crazy. I've tried experimenting
with increasing nbufs to use extra memory for disk caching but the
size and scope of the db is just too large for it to have much overall
benefit. (It will eventually have several hundred million objects in
it)

Sounds like the application needs a redesign to fit with current hardware.
Or you could throw more money at it - use a better raid controller, add a large cache (with battery backup), and spread the data out over many spindles.

I decided to try flash in order to give my hard drive a break. I
expected the r/w speed would be slower, but the average access time
would be quicker. Needless to say it's not working so far, average
write speed with the HD was 100+ keys per second, with the flash it's
about 3-5/sec.

Why isn't flash a good candidate?

For many reasons. For starters, read the limitations section of Flash memory[1].
Also see the flash file systems section, and the Flash memory as a replacement for hard drives section.

Here's the output, there are currently 3 sticks connected (presumably
the entries under /dev/usb3)

What's the difference between UHCI and EHCI? It's an Intel ICH9R
chipset.

ehci is the usb 2.0 high speed controller. This is were you want any device to connect if you need fast data access.

Thanks for your help so far.

# usbdevs -v
Controller /dev/usb0:
addr 1: full speed, self powered, config 1, UHCI root hub(0x0000),
Intel(0x0000), rev 1.00
port 1 powered
port 2 powered
Controller /dev/usb1:
addr 1: full speed, self powered, config 1, UHCI root hub(0x0000),
Intel(0x0000), rev 1.00
port 1 powered
port 2 powered
Controller /dev/usb2:
addr 1: full speed, self powered, config 1, UHCI root hub(0x0000),
Intel(0x0000), rev 1.00
port 1 powered
port 2 powered
Controller /dev/usb3:
addr 1: high speed, self powered, config 1, EHCI root hub(0x0000),
Intel(0x0000), rev 1.00
port 1 addr 2: high speed, power 180 mA, config 1, product
0x0020(0x0020), SanDisk(0x08ec), rev 2.00
port 2 powered
port 3 addr 3: high speed, power 180 mA, config 1, product
0x0020(0x0020), SanDisk(0x08ec), rev 2.00
port 4 addr 4: high speed, power 180 mA, config 1, product
0x0020(0x0020), SanDisk(0x08ec), rev 2.00

At least the memory sticks have attached to the ehci controller - thats good.
Unfortunately, I don't have ny further suggestions - you should get good speeds from your memory sticks when they are connected to an ehci controller.
Do you have the posibility to test with a machine that has an ohci controller?
Just to see if it makes any difference.

1) http://en.wikipedia.org/wiki/Flash_memory
--
Torfinn Ingolfsen,
Norway
.

Relevant Pages

  • How to mount memory stick on sony vaio laptop?
    ... <ACPI PCI bus> on pcib0 ... <Intel 82801G High Definition Audio Controller> ... mem 0xd2300000-0xd2303fff irq 22 at device 27.0 on ... port ...
    (freebsd-questions)
  • Re: Unhappy Xorg upgrade
    ... I tried using pciconf to read the first 2 bytes of config space of the controller which is normally affected, as you can see in the log, and this caused no problems. ... port 1 powered ... vendor = 'ATI Technologies Inc' ... subclass = HOST-PCI ...
    (freebsd-stable)
  • libata problems on Promise SX4000 controller
    ... I had problems getting my Promise SX4000 controller to run with libata. ... i8042 AUX port at 0x60,0x64 irq 12 ... ata_device_add: ata1: probe-wait begin ...
    (Linux-Kernel)
  • Re: USB2 device
    ... Attached you will find my kernel config file... ... Controller /dev/usb0: ... port 1 powered ...
    (freebsd-stable)
  • Re: VIA IDE controller not detected on RELENG_6
    ... controller is being detected as GENERIC ATA, ... atapci0: port ... 0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0xfc00-0xfc0f at device 15.1 on pci0 ...
    (freebsd-stable)