TAR: Speed up compression on multicore systems

This is a little tip to speed up creating tar archive.

By default tar using gzip to compress and if you look at htop output, gzip use only one cpu.

Tar have an argument –use-compress-program, which allow us to set another gzip-ing program.

The most known mutlithreading gzip alternatives is pigz.

So, the tar usage should looks like:

tar --use-compress-program=pigz -cf ...

Under the cut you found the compression time difference between gzip and pigz Continue reading

BASH: Tail follows a file until string isn’t matched

The problem seems pretty easy… for the first look.

# Prepare :>/tmp/output.log (sleep 1s; echo "exit on match" >> /tmp/output.log) & tail -n +0 -f /tmp/output.log | sed '/exit on match/{p;q}'

My first reaction was “Wuuuut?”, because tail isn’t react on SIGPIPE.

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Serial pinout and OpenWrt on Netgear board WNDR4000 rev.0

At last week I installed OpenWrt on my Nergear WNDR4000.
The chip on the board is marked as U12H194T99 instead of *T00, which sets on board rev.1.
The most of staff in the web is about T00, so, it wasn’t so easily find something about T99.
I did a mistakes and got experience. So, I collected a couple of advices for you, %username%.

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Fedora 21: fglrx 15.20 fix again… for Kernel 4.0.8. Is it the last time?

This is a draft, have no enough time, btw, I guess, it could be informative for someone.
I’ll make patch for 4.0.x version of kernel as soon as possible, if I don’t made it – ping me, please, in a comment :)
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