nmon : AIX and Linux performance monitoring tool
cloudibee Nmon : A free performance monitoring script for Linux and AIX systems. It gives lot of performance information and can output the performance analysis results in many format. nmon Document…
Linux
What is Direct I/O
A file is simply a collection of data stored on media. When a process wants to access data from a file, the operating system brings the data into main memory,…
Kernel parameter : file-nr and file-max
file-max : The Linux Operating system kernel allocates file handles dynamically and the value in file-max denotes the maximum number of file handles that the Linux kernel will allocate. When…
Simple perl ipcalc
Here is a simple program to calculate Network address and broadcast address, given input of IP address and netmask. Perl code : #!/usr/bin/perl # Get ipaddress and netmask from user…
Linux modules handling commands
modproble – This command is used for listing and loads the modules on a linux machine. # modprobe -c | less# Generated by modprobe -c (2.4.25)path=/lib/modules/bootpath=/lib/modules/2.4.21-40.ELsmppath=/lib/modules/2.4path=/lib/modules/updatespath=/lib/modules/kernelpath=/lib/modules/fspath=/lib/modules/netpath=/lib/modules/scsi<snip> lsmod – This command…
AIX tips
How to find the processors on an AIX server? # lsdev -C -c processor -S aproc0 Available 00-00 Processor# How to identify the disks attached to an AIX server? #…
Netapp : SNMP tips
How to enable SNMP on a netapp filerfiler1> options snmp.enable on filer1> options snmp snmp.access legacy snmp.enable on filer1> How to set and modify SNMP configration values?filer1*> snmp contact unixfoo@un1xf00.org…
Netapp – Linux iscsi setup
A quick guide to setup IP SAN using Linux-Netapp-iscsi. On Linux server : Install iSCSI initiator (iscsi-initiator-utils rpm) on your linux machine. This will create the necessary binaries and will…
Linux tips : tftpd
When you are trying to analyze/debug tftpd service on your linux boot server , you expect tftpd to return more debug information on the logs. To setup tftp in debug…
Netapp : Pocket Survival Guide
The url http://www.cs.fiu.edu/~tho01/psg/netapp.html has good information on netapp command set and its usage. A quick reference guide for a netapp admin. The site also has tips for Solaris, Veritas, EMC,…
Netapp Tips : Changing exports
/etc/exports file controls the nfs exports on a netapp filer. An easy way to edit this file is described below. From your unix box : rsh netapp rdfile /etc/exports >…
Perl : Xen API
Xen host can be monitored and controlled via Xen API ( it uses XML-RPC communications). Here is a sample how to program using XenAPI. For XenAPI to work, you should…
Filesystem : noatime
Most file systems store and maintain three separate time stamps per file. They are create time last modified time last accessed time The last accessed time stamp may have to…
Netapp : disk zero spares
To clean up the spare disks and zero them, use the below command. Having a zero’d spare disks can reduce time when on volume creation or on volume reconstruction. filer1>…
Linux VLAN configuration
1. Connect the eth0 interface of your linux machine to the switch. 2. Remove the IP Address information on the eth0 interface # ifconfig eth0 0.0.0.0 # ifconfig eth0 up…