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Hi all, I’m very sorry for the interruption on the continuous flow of posts I was managing up until September, but as everyone, when the workload increases, non-essential stuff start to get set aside. Regardless, this projects hasn’t ended, and the flow of new visitors has now got to a stable level. As such, registration for new users and comments are now open to all. Feel free to comment on anything you don’t agree or any other stuff you find relevant.

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Generating random files

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Why on earth would someone want to generate files of random content (not files with random name) ? Well, there is one big reason to do it: generate incompressible files. This seems a small reason, but there are a number os usage scenarios (apart from proving that random content is incompressible), most focus on transmitting files. Although is transparent to most people, but some tools do background compression namely, https, IPSEC and SSL VPNs, etc, and as such, trying to measure real world performance on those require incompressible content. First, how to generate it (assuming you can talk *NIX) ? dd if=/dev/urandom of=random.file bs=1m count=100 Where: if – Input file, in this case the virtual file /dev/urandom of – Output file, the name of the destination file bs – Block Size, the default block size for dd is 512bytes, which makes sense when copying files, but not terribly useful when creating files with a determined size. In this case 1MB count – number of blocks to be copied In this case, I needed to create a 100MB file of random content. The result: > dd if=/dev/urandom of=random.file bs=1m count=100 100+0 records in 100+0 records out 104857600 bytes transferred in 13.460029 …