Linux – How to fix high I/O wait issue?

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Linux server does not responding to application queries. The performance is too low. Underlying disks or SAN LUN’s are normal. From top output found the I/O wait is too high. But there is no I/O intensive tasks are running. While, How to fix high I/O wait issue? Continue reading “Linux – How to fix high I/O wait issue?”


Linux – upgraded HBA firmware not effective

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How to upgrade FC HBA firmware and drivers properly?

We were in progress of upgrading IBM SAN SVC version.  One of the prerequisite is latest recommended HBA firmware and driver level on host systems. Downloaded and installed the latest firmware & drivers from IBM website. But found server still uses old firmware even after reboot. How to make the new firmware effective? Continue reading “Linux – upgraded HBA firmware not effective”


Network interface name changed to “renamex”

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On VMware virtual machine hot added new virtual network interface (NIC). The newly added network interface is of VMXNET3 type. Initially kernel named the new network interface as “eth0”. Post server reboot network interface device name changed from “eth0” to “rename2”. But the other existing network interface name remains same as “eth1”.

[    3.582159] eth0: NIC Link is Up 10000 Mbpsvmware-suse-guest-vmxnet3-nic
[    3.598345] eth1: NIC Link is Up 10000 Mbps
[    3.741375] udev: renamed network interface eth0 to rename2
[  130.435772] bonding: bond0: Adding slave eth1.

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fix network connection slowness

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Network connection slowness is one of the interesting scenarios I came across. It might help someone.

My application servers are placed in one VLAN. And backup server placed in another VLAN. Since it is LAN bandwidth supposed to be 40-50 Mbps. But the connection between both application and backup server were at ~100KBPs transfer rate. I have checked router, firewall and VLAN settings. Everything looks good. No ware bandwidth limit identified.  So, how do I fix network connection slowness issue? Continue reading “fix network connection slowness”


Linux library files

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What is lib files in Linux?
A library(lib) is a file containing compiled code from various object files stuffed into a single file. It may contain a group of functions that are used in a particular context. For example, the ‘pthread’ library is used when thread related functions are to be used in the program.

Broadly, a library (or Program Library) can be of two types : Continue reading “Linux library files”