TestDisk is powerful free data recovery software

https://www.cgsecurity.org/wiki/TestDisk TestDisk is OpenSource software and is licensed under the terms of the GNU General Public License (GPL v2+). TestDisk is powerful free data recovery software! It was primarily designed to help recover lost partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software: certain types of viruses or human error (such as accidentally deleting a Partition Table). Partition table recovery using TestDisk is really easy. TestDisk can […]

Faster Samba (SMB / CIFS) Share Performance

http://www.eggplant.pro/blog/faster-samba-smb-cifs-share-performance/ Is your Samba slow? Samba file sharing is great, but performance under Samba’s default configuration is fairly poor. Here are a few options that I add to my smb.conf to get the speed that I need: # FORCE THE DISK SYSTEM TO ALLOCATE REAL STORAGE BLOCKS WHEN # A FILE IS CREATED OR EXTENDED […]

Linux Performance

http://www.brendangregg.com/linuxperf.html http://techblog.netflix.com/2014/12/introducing-atlas-netflixs-primary.html http://techblog.netflix.com/2015/04/introducing-vector-netflixs-on-host.html http://netflix.github.io/ https://github.com/Netflix/vector http://techblog.netflix.com/2014/11/zerotodocker-easy-way-to-evaluate.html Dtrace: http://crtags.blogspot.com/ http://stackoverflow.com/questions/14375364/dtrace-on-ubuntu-how-to Systemtap: http://manpages.ubuntu.com/manpages/hardy/man1/stap.1.html App Dev Monitor/debug: https://www.takipi.com/

My top 3 Linux commands for logging problems

https://www.rootusers.com/my-top-3-linux-commands-for-logging-problems/ Here I will share a few useful Linux commands I have been using to troubleshoot various server problems. Logging is extremely useful especially when an issue happens at random times or you are not able to yet reproduce the problem. Going back over logs to when a problem was identified will provide you with […]

Troubleshooting High I/O Wait in Linux

http://bencane.com/2012/08/06/troubleshooting-high-io-wait-in-linux/ Linux has many tools available for troubleshooting some are easy to use, some are more advanced. I/O Wait is an issue that requires use of some of the more advanced tools as well as an advanced usage of some of the basic tools. The reason I/O Wait is difficult to troubleshoot is due to […]

How to Filter Unwanted Data without adding to Splunk Daily Indexing Volume

http://networkerslog.blogspot.com/2012/01/how-to-filter-unwanted-data-without.html Splunk is a great tool for consolidating, processing and analysing voluminous data of all sorts, including syslog, Windows events/WMI etc. It’s pretty much like a Google search engine equivalent for your IT environment where you may have daily GBs or even TBs of raw logs and events to content with. Furthermore, you’re likely to find free Splunk […]

Collectl, an all-in-one tool for collecting Linux statistical data

http://honglus.blogspot.com/search/label/Troubleshooting Collectl,collect for Linux, is a single tool which integrates functions of various tools:sar,iostat,mpstat,top,slaptop,netstat,nfstat,ps .. .  – Supported: Linux  – Requirement: Perl  Collectl features:  – run in command line or run as daemon  – Various output formats: raw,gunplot,gexprt(ganglia),sexpr,lexpr,csv(–sep ,)  – Send data to other programs (ganglia) remotely via socket instead of writing to a file  […]

Troubleshooting a high system CPU usage issue on Linux/Solaris

http://honglus.blogspot.com/2010/01/troubleshooting-high-system-cpu-usage.html A Linux server has high %system CPU usage, following are steps to find the root cause of the issue and how to resolve it. Vmstat show %system CPU usage is high. # vmstat 2 procs ———–memory———- —swap– —–io—- –system– —–cpu—— r b swpd free buff cache si so bi bo in cs us sy […]