Flash Openwrt Attitude Adjustment on jjPlus JA76PF2

Preparation and installation of OpenWrt on the router jjPlus JA76PF02

Installing from console with serial connection

You should:

  • Shut down  the board
  • Connect the Ethernet cable to the router’s (WAN port) and the other end to your computer
  • Set the address of the network card on your computer to 192.168.1.1
  • Run a TFTPD server and put in its root the files openwrt-ar71xx-generic-ja76pf2-kernel.bin and openwrt-ar71xx-generic-ja76pf2-rootfs-squashfs.bin
  • Start the tftpd server
  • Connect the serial cable to the board
  • Start a serial terminal with parameters 8 n 1 115200
  • Turn on the board
  • and hit Ctrl-C to stop at the bootloader’s command line.  Now you are in RedBoot

Continue reading Flash Openwrt Attitude Adjustment on jjPlus JA76PF2

Replacing a Hard Disk Drive of a ZFS pool in a NAS4Free server

Being in the business of database management, it’s hard for me to admit that I’ve lost personal data, but after riding the storm in more occasions than I can remember or care to know, I wouldn’t be honest if I didn’t stress over and over again the fragile nature of XXI century storage media . . . → Read More: Replacing a Hard Disk Drive of a ZFS pool in a NAS4Free server

NAS4Free under ESXi

One surprising thing I noticed when testing out NAS4Free is the lack of documentation with regards to installation on VMware. I can understand a viewpoint that a NAS is a NAS and not to be anything else, but what about working loads where that kind of raw performance is not required (granted the virtualization overhead these days should be within 5-10% of physical). In any case the below instructions are written with running ESXi 5.1 with NAS4Free 9.1.0.1, for ease of reading the directions are broken down into three sections. Continue reading NAS4Free under ESXi

How to unregister vCenter plugin/extension using the MOB

I saw a post on the VMTN forums the other day about unregistering a vCenter plugin. The user had a bad installation of an early preview of NetApp’s VSC utility. After uninstalling the plugin, the user was still unable to unlink the plugin from vCenter. There is actually a pretty simple solution to this . . . → Read More: How to unregister vCenter plugin/extension using the MOB

VMware vCenter 5.1 Service will not start on Windows Server 2012

The vCenter Server is dependant on the ProtectedStorage Service that no longer existas in windows 2012

ProtectedStorage is a dependancy for most applications using .NetFramework in Windows 2012. A simple workaround is to remove the dependancy which will not affect your production application anyway unless you have clustering features unabled for this application.

Browse . . . → Read More: VMware vCenter 5.1 Service will not start on Windows Server 2012

The Easiest Way To Update A Dell Server’s Firmware

With the advent of VMware ESXi there are fewer and fewer good ways to update your Dell PowerEdge system’s firmware, seeing as you can’t just run the System Update Utility from the console OS anymore. Making things more difficult, I think I’ve seen every failure mode Dell’s iDRAC has to offer, from the inability . . . → Read More: The Easiest Way To Update A Dell Server’s Firmware

Tweaking Java.exe memory usage on vCenter Server 5.1

During the upgrade of my home lab from vSphere 5.0 to vSphere 5.1 I have noticed that there is more memory consumption on my vCenter Server than before the upgrade. According to the vSphere Installation and Setup Guide, this happens because vCenter Server includes several Java services in the installation (VirtualCenter Management . . . → Read More: Tweaking Java.exe memory usage on vCenter Server 5.1

NetFlow: installation and configuration of NFDUMP and NfSen on Debian

After the brief overview about the installation of flow-tools and FlowViewer, in this post I’d like to share my experience about the setup of a basic solution based on another pair of tools: NFDUMP and NfSen. As always on my posts, the starting point is a fresh Debian 5.0 setup. Continue reading NetFlow: installation and configuration of NFDUMP and NfSen on Debian

Postfix cheat-sheet

How to check mail queue?

$postqueue -p

How to flash/resend the queue mails?

$postqueue -f

How to check the basic config?

$postconf -n

How to check whole config?

$postconf

How to make all queue as renew queue? Continue reading Postfix cheat-sheet

Postfix configure anti spam with blacklist

Postfix is free and powerful MTA. You can easily configure Postfix to block spam. You need to add following directives to /etc/postfix/main.cf file:

disable_vrfy_command = yes : Disable the SMTP VRFY command. This stops some techniques used to harvest email addresses.

smtpd_delay_reject = yes : It allows Postfix to log recipient address information when rejecting a client name/address or sender address, so that it is possible to find out whose mail is being rejected.

smtpd_helo_requi
red = yes
 : Require that a remote SMTP client introduces itself at the beginning of an SMTP session with the HELO or EHLO command. Many spam bot ignores HELO/EHLO command and you save yourself from spam. Following lines further restrictions on HELO command:
smtpd_helo_restrictions = permit_mynetworks,
reject_non_fqdn_hostname, Reject email if remote hostname is not in fully-qualified domain form. Usually bots sending email don’t have FQDN names.
reject_invalid_hostname, Reject all bots sending email from computers connected via DSL/ADSL computers. They don’t have valid internet hostname.
permit Continue reading Postfix configure anti spam with blacklist