Tool to simulate non-sequential disk I/O (simulate db file sequential read) in C POSIX


 
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Old 06-18-2011
Happy with it not being completely random, as long as it jumps around enough to not catch itself on the read advance routines when running on the SAN, and as simulation goes, the database would more than likely read specific files or parts of files more than others anyway.

Here comes my next exciting problem, a database will only read a certain amount of time, other bits are sorting, writing and whatever else the database gets up to. So I am thinking of adding how manny cycles there are between reads, because just doing random reads and nothing else is giving rather silly results. In its purest form I seem to be able to get 100% WaitI/O and read about 6-12 Kb/s, which is pretty impressive in its ow right.

And todays exiting question, anyone feel like guessing how many cycles in a million that a rather streamlined database spends reading disk dataSmilie
Anyone who guesses the right answer wins an icecream, collectable in Camden, London (U.K.)

/Ben
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PK-DEBUGINFO-INSTA(1)						  [FIXME: manual]					     PK-DEBUGINFO-INSTA(1)

NAME
pk-debuginfo-install - Debugging Packages Installer SYNOPSIS
pk-debuginfo-install [--help] [--verbose] [--simulate] [--no-depends] DESCRIPTION
This manual page documents briefly the pk-debuginfo-install command. pk-debuginfo-install is the command line client for installing debuginfo packages. WHY DO I NEED DEBUGINFO PACKAGES
? When a program crashes, it's often useful to send the developer a backtrace which contains symbol names and variable contents, rather than memory addresses. To make this possible, extra packages called debug packages can be installed. OPTIONS
This program follows the usual GNU command line syntax, with long options starting with two dashes (`-'). A summary of options is included below. --help Show summary of options. --noninteractive Do not be interactive and skip the confirmation before the packages are installed. --verbose Show extra debugging information. --simulate Don't actually install any packages, only simulate what would be installed. --no-depends Do not scan for, or install dependencies of the core packages. --quiet Do not display information or progress to the terminal. RETURN VALUES
0 Success, at least one package was installed 1 Failed with miscellaneous internal error. 3 Failed to get software sources list. 4 Failed to enable software sources. 5 Failed as nothing to do. 6 Failed to find dependent packages. 7 Failed to install. 8 Failed to disable software sources. SEE ALSO
pkmon (1). pkcon(1). AUTHOR
This manual page was written by Richard Hughes richard@hughsie.com. COPYRIGHT
Copyright (C) 2009 Richard Hughes [FIXME: source] 29 July,2009 PK-DEBUGINFO-INSTA(1)