Leonard Nimoy 1931-2015

February 27th, 2015 No comments

A life is like a garden. Perfect moments can be had, but not preserved, except in memory. LLAP

Categories: cultural Tags:

News Server

February 24th, 2015 No comments

Hi,

i moved the blog (which is more of an archive of the good ol’ times these days) to a new server. Lets see if everyhting still works . . .

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Patching Running Linux Kernel

October 27th, 2014 No comments
Categories: linux Tags: , , ,

emojis – an universal language

October 16th, 2014 1 comment

Why was this emoji rejected from being included in UTF? ;-)

Sad Bone Saw

Here’s a list of seeminlgy rejected emojis: rejectedemojis.tumblr.com

Categories: fun, nerdcore Tags:

RESTful APIs and Python

September 16th, 2014 No comments
Categories: software Tags: ,

Secret Coders

September 5th, 2014 No comments

Really nice graphic novel about how to learn coding.

http://www.wired.com/2014/09/secret-coders-gene-yang

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adding pci device to vm

August 27th, 2014 No comments

If you want to use a pci device in a vm, you first have to detach it from the host. List the devices and look for the one you want to use in the vm:

virsh nodedev-list --tree

In my case (CentOS7) I needed to enable iommu in order for this to work. This involves adding a kernel parameter:

kpath=`grubby --default-kernel`
grubby --update-kernel=$kpath --args="intel_iommu=on”
cat /proc/cmdline

After the reboot, /proc/cmdline should now include the iommu flag. Also check whether all the needed modules are loaded, in my case these are:

  • vfio_pci
  • vfio_iommu_type1
  • vfio
  • kvm_intel
  • kvm

You can then detach the pci device:

virsh nodedev-dettach pci_0000_05_00_1

I then used virt-manager, powered off the vm, and added the “Physical Host Device”.

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virt-manager as non-root user

August 26th, 2014 No comments

trying to start virt-manager as a normal user will yield a “Unable to open a connection…” message. To fix this, we need to change access permissions for libvirtd.

Edit /etc/libvirt/libvirtd.conf:

echo "unix_sock_group = \"libvirt\"
unix_sock_rw_perms = \"0770\"
auth_unix_rw = \"none\"
">>/etc/libvirt/libvirtd.conf

We also jneed to create the group “libvirt” we just set:

groupadd -g $GID libvirt; usermod -a -G libvirt $USER

Be sure to set $GID and $USER correctly.

A restart of the daemon should then do the trick:

service libvirtd stop; service libvirtd start

if virt-manager the shows only squares instead of letters, install the necessary fonts:

yum -y groupinstall "Fonts"

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SQLite rowid picking joke….ehm algorithm

July 22nd, 2014 No comments

I laughed very hard at this:

“The usual algorithm is to give the newly created row a ROWID that is one larger than the largest ROWID in the table prior to the insert. If the table is initially empty, then a ROWID of 1 is used. If the largest ROWID is equal to the largest possible integer (9223372036854775807) then the database engine starts picking positive candidate ROWIDs at random until it finds one that is not previously used. If no unused ROWID can be found after a reasonable number of attempts, the insert operation fails with an SQLITE_FULL error.”

Source: sqlite.org

Categories: fun, nerdcore, software Tags: ,

heartbleed

April 8th, 2014 1 comment

Enough word already on all channels, here’s a short one-liner to check which procs are still using the vulnerable old libs after the upgrade:
sudo lsof -n | grep ssl | grep DEL

Oh, and if you want to test wether a site is still vulnerable: https://gist.github.com/takeshixx/10107280

Time to revoke all those lingering server certs . . .

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