Portmap is a service that converts RPC program numbers into protocol port numbers. It must be running in order to make RPC calls. Portmap makes the dynamic binding of remote programs possible. NFSv3 is based on portmap. We will dive…
The rpcbind is a utility that converts RPC program numbers into universal addresses. It must be running on the host to be able to make RPC calls. We will dive into RPCbind today to see how it works. Understanding RPC…
Network File Sharing (NFS) is a protocol that allows us to share directories and files with other Linux clients over a network. The ports for NFS are confusing for many people. We will deep dive into this today. NFSv3 Port…
This article is part of the following series. Linux high IO wait is a common Linux performance issue. Today we will look at what io wait means and what contributes to this problem. Hope this can give you more…
Timeo is a timeout mount option in NFS mount. It is the timeout value that the NFS client uses to wait for a response before it retries an NFS request. Let’s dive into the details about what this timeout value…
File system is an important part of Linux world. We collect 10 useful file system concepts below to help you understand what file system is. Important File system Concepts
Raw IO and Direct IO are both bypassing file system cache. Here are more details about these two IOs. This can help us understand the difference and troubleshoot easier when we get a file system issue. Difference Between RAW IO…
This article is part of the following series. Disk utilization in iostat command is a key metric to check if a disk is busy or not in Linux. It is used to calculate the time percent that a disk…
Linux IOwait is a common Linux performance issue. Today we will look at what iowait means and what contributes to this problem. Hope this can give you more ideas about high IOwait issue. IOwait on Linux The iowait column on…
How to get HBA WWPN on Linux is a common task for a storage engineer. We need the WWPN to configure zone on the switch side.We will look at this question today. In our SAN environment, we have two HBAs…
