Thursday, September 24, 2015

12 Things do to after just started your DigitalOcean VPS

Recently I helped one of my client to setup a VPS on DigitalOcean (DO). The price is very competitive (the cheapest plan is $5 per month) and they offer SSD as the storage. I highly recommend to give a try if someone is looking for a virtual hosting.

Actually a VPS is just a server running on other location. Once you subscribe a plan and start to OS, it's your responsibility to maintain the system.

The steps below are to enhance the security once the server is deployed ( we are using Ubuntu 14.04 in this case). The objective is to harden the server so that it can only be accessed from a client with ssh

1. Setup ssh keyfrom a linux server at home or office. Assumed you have a linux client with a user "user1"

Friday, September 11, 2015

Benchmarking of Hard disks on N54L using Bonnie++

Getting the hard disk details

First we use smartctl to get the details, you can see there are 3 disks. 2x WD Green 2TB 5400rpm and 1x HP 500GB 7200rpm. The HP one is bundled and I think it's not enough for me to store my data So I buy the WD disks and make it as a mirror.

#smartctl -i /dev/sda
smartctl 6.4 2015-06-04 r4109 [x86_64-linux-3.14.51-1-lts] (local build)
Copyright (C) 2002-15, Bruce Allen, Christian Franke,

Model Family:     Western Digital Green
Device Model:     WDC WD20EZRX-00D8PB0
Serial Number:    WD-xxxxxxxxxx
LU WWN Device Id: 5 0014ee 6055d1735
Firmware Version: 80.00A80
User Capacity:    2,000,398,934,016 bytes [2.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5400 rpm
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ACS-2 (minor revision not indicated)
SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is:    Fri Sep 11 17:09:32 2015 HKT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled


Friday, August 28, 2015

Pass Store (Password Manager in command line)

Everybody is facing a problem: too many password to remember. If there are too many to store in brian, then its time to store somewhere else. Some people will simply write on a notebook, some will store it in an excel, and some will download a password manager such as KeePass/KeePassX and LastPass. But as a Linux guy I would like to try another tool in command line: Pass (

Why need a command line password manager? Having a command line password manager can provide flexibility:

  • you use SSH to connect to the Linux so it is secure and you can view a password of a particular account without touching a mouse
  • you can write simple script to deal with the passwords. for example, generate a number of account/ password pair, or dump a password list
  • This tool is very lightweight. You can store your passwords in a Raspberry Pi !

If you visit the website you may find it is not difficult to use. However, there are some tricks

1. You must setup gpg keyrings before initialising the pass store
2. The name of the pass store is the ID of the gpg key.

Once you setup the pass store you are good to enjoy this tool.

The following steps are the example:

Tuesday, August 25, 2015

HP Gen7 N54L Hardware Upgrade

I have a HP Gen7 N54L. Although Gen8 is released but it also makes N54L more attractive. It is a Microserver and it's worth to get one as a home server. There is a 4 bay enclosure. If you make use of the space of optical drive and the eSata output, the server can serve totally 6 SATA devices which is good enough for a storage server for a SME. 

Originally the configuration is a 4GB ECC memory with a 500GB Black disk. The CPU is AMD Turion(tm) II Neo N54L Dual-Core Processor. It is embedded in the mainboard so there is no way to upgrade it. Also, the main board doesn't have any USB3.0, which is not acceptable nowadays. 

So what can we do in order to make it more productive? For me, I have purchased the following :
  • 2x 2TB Green disks (with software raid, will explain later)
  • Add 4GB non-ECC memory (totally 8GB)
  • Add a USB3.0 pci low profile adapter
I also upgraded the BIOS which can make the harddisks hot pluggable. 

Since I need some time to make a short procedure for the hardware, I just show the result at the moment.

# free
total used free shared buff/cache available
Mem: 8052260 826372 6648096 14800 577792 6854592
Swap: 0 0 0
# lspci |grep -i USB.3
02:00.0 USB controller: Renesas Technology Corp. uPD720202 USB 3.0 Host Controller (rev 02)

Of course I am a Linux guy so it is expected I installed a Linux on it. You can see there are 6GB free right now. And I can even use the USB3.0 ports to connect more hard disks (to backup, for example).

Friday, June 28, 2013

Restore HP-UX from ignite tape (with screen dump)


To restore HP-UX (11i, 11.23 should work) from a backup (make_tape_recovery)

  1. Login MP console and recycle it
  2. "CO" to console
  3. Within that "10 seconds", press any key and see the menu
    ---- Main Menu ---------------------------------------------------------------
         Command                           Description
         -------                           -----------
         BOot [PRI|ALT|]             Boot from specified path
         PAth [PRI|ALT] []           Display or modify a path
         SEArch [DIsplay|IPL] []     Search for boot devices
         COnfiguration menu                Displays or sets boot values
         INformation menu                  Displays hardware information
         SERvice menu                      Displays service commands
         DIsplay                           Redisplay the current menu
         HElp [|]           Display help for menu or command
         RESET                             Restart the system
    Main Menu: Enter command or menu > sea
  4. Insert the tape and run "SEA" to search devices
    Main Menu: Enter command or menu > SEA
    Searching for potential boot device(s)
    This may take several minutes.
    To discontinue search, press any key (termination may not be immediate).
       Path#  Device Path (dec)  Device Path (mnem)  Device Type               Rev
       -----  -----------------  ------------------  -----------               ----
       P0     0/0/2/0.0          ide.0               Random access media       1    
       P1     0/1/1/0.0          intscsia.0          Random access media       1    
       P2     0/1/1/1.4          intscsib.4          Sequential access media   1    
    Main Menu: Enter command or menu >
  5. "P2 0/1/1/1.4 intscsib.4 Sequential access media 1" -> which is the tape drive