Adding large Disks

Adding large disks/RAIDs post-install Run parted on the new raid, like so: parted /dev/sdc ... where sdc is the new device that you haven't seen before. If you are baffled about what the new device is called, check dmesg and/or just ls /dev and look for new, unused devices. Next, make the label: (parted) mklabel gpt (parted) print Model: HP LOGICAL VOLUME (scsi) Disk /dev/sdc: 33.0TB Sector size (logical/physical): 512B/4096B Partition Table: gpt Number Start End Size File system Name Flags And now make the first partition. With disks up to a certain…Read more …

10 Tips for Hardening a Linux Server

In light of all the complex and specialized attacks on Internet-facing servers, it’s very important to protect your cloud assets from malicious assailants whose sole purpose is to leach, alter, expose, siphon sensitive data, or even to shut you down. From someone who does a lot of Linux deployments, I like to have handy a Linux template with some extra security policies configured. Securing your environment starts during the ordering process when you are deploying server resources. Sometimes you want to deploy a quick server without putting it behind an extra hardware firewall…Read more …

Software RAID vs hardware RAID: Pros and cons

Redundant Array of Independent Disks or RAID takes multiple disk drives and creates arrays that are resilient and highly available by mirroring and striping data across them. It also builds in the means to recover from disk failure using parity data. The different ways that mirroring, striping and parity are used defines the different RAID levels. Processing is required to carry out those actions, and that can take place on the host server's OS or in the storage array or controller. This is also called software RAID vs. hardware RAID. So, what are…Read more …

About Swap Space in Linux

Linux divides its physical RAM (random access memory) into chucks of memory called pages. Swapping is the process whereby a page of memory is copied to the preconfigured space on the hard disk, called swap space, to free up that page of memory. The combined sizes of the physical memory and the swap space is the amount of virtual memory available. Swapping is necessary for two important reasons. First, when the system requires more memory than is physically available, the kernel swaps out less used pages and gives memory to the current application…Read more …

Using the ‘for’ Loop in Bash

Ever have a bunch of files to rename or a large set of files to move to different directories? Ever find yourself copy/pasting nearly identical commands a few hundred times to get a job done? A system administrator's life is full of tedious tasks that can be eliminated or simplified with the proper tools. That's right ... Those tedious tasks don't have to be executed manually! I'd like to introduce you to one of the simplest tools to automate time-consuming repetitive processes in Bash — the for loop. Whether you have been programming for a…Read more …

What is the difference between UDP and TCP

What is the difference between UDP and TCP internet protocols? Transmission Control Protocol (TCP) and User Datagram Protocol (UDP)is a transportation protocol that is one of the core protocols of the Internet protocol suite. Both TCP and UDP work at transport layer TCP/IP model and both have very different usage. Difference between TCP and UDP TCP UDP Reliability: TCP is connection-oriented protocol. When a file or message send it will get delivered unless connections fails. If connection lost, the server will request the lost part. There is no corruption while transferring a message.…Read more …

How to change the hostname for a vm in onapp

For some reason, the guys from onapp didn't include an option to change the vm hostname from the panel, so, at least for the moment, the only way to change it is to make the change in the onapp database. Login to onapp and find the vm, click on it and you should have a link similar with http://domain.com/virtual_machines/svaolrezaj1vz0 In this case, the last part “svaolrezaj1vz0? is the vm id, you will need it to run the sql query. Now, login to the onapp server via ssh and run: root@justgeek [~]# mysql -uroot -p…Read more …

cPanel :: Unable to locate clamd

If you are getting the error cPanel :: Unable to locate clamd then please follow the steps below. If you are not able to restart clamd on cpanel server and getting following error: root@justgeek [~]# /scripts/restartsrv_clamd Unable to locate clamd Please follow the steps as given below: # Red Hat Enterprise Linux 5 / i386: root@justgeek [~]# rpm -Uhv http://apt.sw.be/redhat/el5/en/i386/rpmforge/RPMS/rpmforge-release-0.3.6-1.el5.rf.i386.rpm # Red Hat Enterprise Linux 5 / x86_64: root@justgeek [~]# rpm -Uhv http://apt.sw.be/redhat/el5/en/x86_64/rpmforge/RPMS//rpmforge-release-0.3.6-1.el5.rf.x86_64.rpm Then install it through yum: root@justgeek [~]# yum install clamd And finally restart clamd service: root@justgeek [~]# /scripts/restartsrv_clamdRead more …

DRAC Console Java Virtual Machine (JVM) not supported

When trying to open a console from one of my Dell servers using the DRAC 4/P card I got an error: “The Java Virtual Machine (JVM) currently installed is not supported. Please refer to the DRAC 4 User’s Guide for information on installing a supported version of the JVM.” After some testing it turns out DRAC (Dell Remote Access Card) does not play well with Java 7. Current versions I’m testing with: DRAC 4/P Firmware version 1.75, Java 6 Update 33, Java 7 Update 5 Solution As Java6 and Java7 can coexist, the…Read more …

Changing the default Plesk Backup Repository location ?

How do I change the default Plesk Backup Repository location ? Windows 32 bit edition You can edit default server backup repository directory path through registry. Go to Regedit and then browse the keys HKEY_LOCAL_MACHINE\SOFTWARE\PLESK\PSA Config\Config Right Click on variable “DUMP_D” select Modify and set the server backup repository path as you wish. Default Directory Path for Plesk Backup is “C:\Program Files\Parallels\Plesk\Backup\”. Go ahead and change it to a location of your wish, say “E:\Backup” Windows 64 bit edition Again it’s the registry only, but the location may be a bit different. You…Read more …