Storage Knowledge for Unix/Linux System Administrator
Storage Knowledge for Unix/Linux System Administrator As a Unix/Linux system administrator you need to deal with SAN storage and here are some of the functionalities. 1. New SAN storage request... Read more »

change open files limit in linux
How to change open files limit in linux You can change the open file limits for individual users using the following method. You might want to also set in /etc/security/limits.conf... Read more »

LVM command help
LVM command help Available lvm commands: Use ‘lvm help ‘ for more information dumpconfig      Dump active configuration formats               List available metadata formats help Display help for commands lvchange            Change the... Read more »

Linux server is not booting and going to grub prompt
Linux server is not booting and going to grub prompt Some times when you boot the server it goes to grub prompt, you can assume there is a problem with... Read more »

How to rescan Fiber Channel and SCSI storage
You can force a rescan for SCSI drives like this: echo “- – -” >/sys/class/scsi_host/host Same for FiberChannel: echo “1″ >/sys/class/fc_host/host Also, you can reboot the system to Rescan.

NMAP command (How to check whether port is open or close)
NMAP command to check whether port is open or close Most of the time when there is a problem connecting to any specific port we use telnet command to verify,... Read more »

HBA card troubleshooting
HBA card troubleshooting  HBA card is configuration is very important and if you can’t configure HBA card, then system won’t see your storage and you will have big issues. Make... Read more »

vmstats explanation
vmstat is one of the popular tool to analyze the Linux / UNIX server performance. # vmstat  1   5 procs ———–memory———- —swap– —–io—- –system– —-cpu—- r  b   swpd   free   buff ... Read more »

How to diffierenate from Local disks vs SAN
How to differentiate from Local disks vs SAN Some times system admins get confused that disks are from SAN or local disk. Please check the following information and this server... Read more »

Linux memory usage calculation
Linux memory usage calculation Most of the people get confuse about Linux memory usage. When you looked at used cloum, it says 3535 M, it doesn’t mean that system is... Read more »