my n0tes

Tuesday, January 21, 2014

A little note about ALSA and x220i thinkpad

First of all you need to find out sound cards indexes.


#> cat /proc/asound/cards

0 [PCH]:         HDA-Intel - HDA Intel PCH

                 HDA Intel PCH at 0xf2520000 irq 42

29 [ThinkPadEC]: ThinkPad EC - ThinkPad Console Audio Control

                 ThinkPad Console Audio Control at EC reg 0x30, fw unknown

so HDA Intel PCH has index 0


#> /etc/asound.conf 

pcm.!default {

   type hw

   card 0

}

ctl.!default {

   type hw

   card 0

}


cat /etc/modprobe.d/alsa-base

options snd-hda-intel model=laptop index=0

options snd-hda-intel model=thinkpad

Monday, January 20, 2014

Remote reset or reboot Yealink T20\T22

Just send HTTP POST to:
http://192.168.1.2/cgi-bin/ConfigManApp.com (192.168.1.2 - phone address)
with header for basic auth:
'Authorization: Basic KJDSGHj54KLDSJ3='
and content:
PAGEID=7&CONFIG_DATA=RESETFACTORY - for reset

PAGEID=7&CONFIG_DATA=REBOOT - for reboot

Python example


#> python

import urllib2

post = urllib2.Request('http://192.168.1.2/cgi-bin/ConfigManApp.com?Id=7')

post.add_header('Authorization','Basic KJDSGHj54KLDSJ3=')

response = urllib2.urlopen(post, 'PAGEID=7&CONFIG_DATA=RESETFACTORY')



response.msg.lower() == 'ok'

response.code == 200



response.read()

>>> '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">\n<html><body><script type="text/javascript">if(parent && parent.onloadIFrame)\n   parent.onloadIFrame("Talking");\nelse\n   window.location.replace(\'/cgi-bin/ConfigManApp.com?Id=13\');\n</script></body></html>'

>>> '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">\n<html><body><script type="text/javascript">if(parent && parent.onloadIFrame)\n   parent.onloadIFrame("RESETFACTORY");\nelse\n   window.location.replace(\'/cgi-bin/ConfigManApp.com?Id=13\');\n</script></body></html>'

Tuesday, November 12, 2013

pic

Friday, October 25, 2013

Snake's magic

Simple example:


!#/usr/bin/env python



x = 'abcdef'



if x.find('z'):

    print 'True'

else:

    print 'False'

What result will you get after run this python code ? False ?, are you sure ?

Wednesday, July 17, 2013

Linux CentOS 6 KVM hot add device

First of all, you should avoid using virsh attach-disk with its limited amount of options. Instead, I suggest to specify the exact disk format you prefer in a separate, temporary XML file, like this:

<disk type='file' device='disk'>

  <driver name='qemu' type='qcow2' cache='writeback'/>

  <source file='/home/gert/kvm/testdomain-vdb.img'/>

  <target dev='vdb' bus='virtio'/>

</disk>

Before adding it, make sure the hotplug kernel modules are loaded in the guest:

modprobe acpiphp

modprobe pci_hotplug

Some distributions, including recent CentOS/RHEL/Fedora have this built-in in the kernel. In this case, check for CONFIG_HOTPLUG_PCI_ACPI. If it's y, then you're all set.

Finally, add it to the running VM using

virsh # attach-device [domain] /path/to/disk.xml
(optionally, add the --persistent option to let Libvirt update the domain XML definition 'persistent'.)

In the guest, the kernel should now be triggered, as can be checked with dmesg:
[ 321.946440] virtio-pci 0000:00:06.0: using default PCI settings
[...]
[ 321.952782] vdb: vdb1 vdb2

This also works perfectly using the GUI-enabled virt-manager application.

source

How to clear memory (caches) on Linux

Since 2.6.16 you need only echo to clear cached memory on Linux box.

This will clear all cached memory.

echo 3 > /proc/sys/vm/drop_caches

You can clear only part of it by using 1 or 2. All options:

1 to clear cached pages.
2 to clear dentries and inodes.
3 to clear all cached memory.

Thursday, February 14, 2013

Copy LVM volume over network to another LVM pool

We need to copy huge LVM volume from HOST_A to LVM on HOST_B. It can be virtual machine disk for example.
On HOST_B create LVM_HOST_B volume and after that dd over ssh with gzip. And do not use /dev/mapper

#> dd bs=1M if=LVM_HOST_A | gzip --fast -c | ssh HOST_B "gzip -d -c | dd bs=1M of=LVM_HOST_B"

Awesome!

pv utility can show progress bar for dd. pv - monitor the progress of data through a pipe.

pv -ptrb

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