iostat, vmstat, netstat – Performance Monitoring & Tuning in Unix & Linux

iostat, vmstat, netstat are the tools in Linux and Unix operating system which provides important system performance data relating to disk, memory network and cpu. By analyzing the data it is possible to determine the potential bottleneck which is impacting the system performance and take corrective action accordingly.

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5 Things Slowing Down Your Internet Speed and What to Do about Them

Network Speed

There are few things more frustrating than slow Internet. When a movie keeps freezing or conference calls keep dropping out, it can drive anyone crazy. Individuals who use the internet for business can even lose money when their connection isn’t up to par. Many factors can cause slow speeds but the good news is that many of them can be addressed. Doing regular speed tests can help to quickly identify patterns and highlight when something may be going wrong. Let’s discuss some of the things which may be causing your Internet to slow down and how you can respond. Continue reading “5 Things Slowing Down Your Internet Speed and What to Do about Them”

Application Monitoring

Application monitoring

Application monitoring is a very important aspect of a project but unfortunately not much attention is paid to develop the effective monitoring while the projects are still movingh to completions. Once project is complete & live lack of proper monitoring costs in terms of downtime when support persons are not aware if application is having some problems or application not working at all. Continue reading “Application Monitoring”

fsck Command – Check & Repair Linux & Unix File Systems

fsck, similar to chkdsk in windows, checks and repairs the file system in Unix & Linux operating systems. Learn about fsck modes, phases & fsck errors messages

fsck, File System Consistency checK, is a system utility in Unix, Linux and other Unix like systems for checking and repairing file system inconsistencies.

File system can become inconsistent due to several reasons and the most common is abnormal shutdown due to hardware failure, power failure or switching off the system without proper shutdown. Due to these reasons the superblock in a file system is not updated and has mismatched information relating to system data blocks, free blocks and inodes.

fsck in Linux

fsck in this document is refered with reference to ufs file system but it can be used in Linux systems as

fsck -t ext2 /dev/sda3
or
fsck.ext2 /dev/sda3
fsck.ext4 /dev/sda3
fsck.ext3 /dev/sda3

it returns with any of the followig code

0 – No errors
1 – File system errors corrected
2 – System should be rebooted
4 – File system errors left uncorrected
8 – Operational error
16 – Usage or syntax error
32 – Fsck canceled by user request
128 – Shared library error

fsck checks the file systems defined in /etc/fstab in Linux and /etc/vfstab in Unix systems

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