Diagnosing & fixing unacceptably slow I/O performance

[Vadi]

Hm - rebooted, no ext4 dmesg errors yet, however there are dependency issues now. Wireless does work, but:

$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
 crda : Breaks: wireless-crda (< 1.15) but 1.14 is installed
E: Unmet dependencies. Try using -f.
$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Correcting dependencies... Done
The following package was automatically installed and is no longer required:
  bzr-dbus
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  wireless-crda
The following packages will be upgraded:
  wireless-crda
1 upgraded, 0 newly installed, 0 to remove and 22 not upgraded.
1 not fully installed or removed.
Need to get 2,658 B of archives.
After this operation, 91.1 kB disk space will be freed.
Do you want to continue [Y/n]? y
Get:1 http://mirror.aarnet.edu.au/pub/ubuntu/archive/ precise/main wireless-crda i386 1.16 [2,658 B]
Fetched 2,658 B in 0s (22.7 kB/s)        
dpkg: dependency problems prevent configuration of wireless-crda:
 crda (1.1.2-1ubuntu1) breaks wireless-crda (<< 1.15) and is installed.
  Version of wireless-crda to be configured is 1.14.
dpkg: error processing wireless-crda (--configure):
 dependency problems - leaving unconfigured
No apport report written because the error message indicates its a followup error from a previous failure.
                                                                                                          Errors were encountered while processing:
 wireless-crda
E: Sub-process /usr/bin/dpkg returned an error code (1)

[Vadi]

That script didn't help and it made quite a mess that was difficult to solve, to put it politely. I've worked it out with some surgical use of dpkg --force-depends --purge - back to where I've started now. Maybe I'll try a realtime kernel, that should have less of an effect on the system due to IO waiting.

[Kano]

Usually wireless-crda does not install when crda is already installed. in newer systems this is just a meta package and can be safely removed. I just dl an older version that is NOT a meta package as it is a depend. I dont get why this should be so problematic.

[Vadi]

Hm, well - http://pastebin.com/iWeXvDu0, http://pastebin.com/J77uyYpf - it wasn't working out. I don't understand the system well enough to know why.

[AlbertP]

Could you run lspci and post the output?

[Vadi]

Yeah, certainly - here it is:

00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 12)
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 12)
00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 05)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 05)
00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 05)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev a5)
00:1f.0 ISA bridge: Intel Corporation Mobile 5 Series Chipset LPC Interface Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 4 port SATA AHCI Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 05)
00:1f.6 Signal processing controller: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem (rev 05)
02:00.0 Ethernet controller: Broadcom Corporation NetLink BCM57780 Gigabit Ethernet PCIe (rev 01)
04:00.0 Network controller: Atheros Communications Inc. AR928X Wireless Network Adapter (PCI-Express) (rev 01)
ff:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers (rev 02)
ff:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 02)
ff:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 02)
ff:02.1 Host bridge: Intel Corporation Core Processor QPI Physical 0 (rev 02)
ff:02.2 Host bridge: Intel Corporation Core Processor Reserved (rev 02)
ff:02.3 Host bridge: Intel Corporation Core Processor Reserved (rev 02)

[AlbertP]

I thought it might have been a faulty SATA-600 port which is a bug in early Intel 6 Series chipsets, but you have a 5 Series chipset.

[Kano]

@Vadi

did apt-get install -f not fix the issue?

[Vadi]

Ah. Pity it's not a hardware issue, could have gotten that fixed by the manufacturer.

The apt-get install -f wasn't fixing it - it was happy but then it'd spit some errors out. I've got it worked in the end with dpkg force remove, ignoring dependencies I uninstalled the wireless and kernel, and installed wireless back - that's OK now.

[Kano]

The kernel would work you can modifiy the script not to dl wireless-crda. It is a very short script. In debian wheezy is crda preinstalled, as the dpkg -i used in the script is without override you usually only get a warning but not more, the u kernels however only install on 32 bit systems correctly because of too new libc6 for the 64 bit kernels. maybe your system had wireless-cdra as meta package installed not just cdra, could be a possible cause for the error.