LXF182 April 2014

Update from linux mag Apirl 2014.

ReactOS is a free open source OS, but not a Linux or Unix ased. It has been designed to be binary compatible with Windows, letting you run Win app natively.
http://www.reactos.org/


Robolinux
Debian based linux. for people who are new to linux + high level of security. It come with vm for windows xp and 7.
http://www.robolinux.org/


Quirky
A puppy linux come with small size sutable for resurrectin your old PCs.


NAS4Free
A FreeBSD based system that turn your PC to NAS.It come with web interface that easy to manage.
http://www.nas4free.org/

Protecting your privacy (Beat the NSA)
Browsing the web :
* delete cookie
* opt out ad tracking network (networkadvertising.org/choices)
* delete LSO (flash cookie)
* switch to SSL

Cover the track
* use VPN
* use Tor, JonDo
* AdBlock

Email & chat.
* PGP : email client with PGP plugin
* Mailvelope plugin for Web mail service
* cryptoCat plugin for IM

Hardware
* Encrypt drive
* TrueCrypt
* Switch distro such as tails.


Secure Android
* andriod app ask set of permission before installing it.
* use Xposed, XPrivacy to control specific permission
* remove EXIF infor from picutre before sharing or uploading to google drive, dropbox.
* use EncFS on desktop if you use google drive or Dropbox. Store encrypted folder in the cloud instead. This will make all your data on those service encrypted.

Communicate securely
* Phony add-on : customise the use-agent.
* use self-destructing cookies add-on.
* CleanQuit add-on : remove all previos session doloadhistory and site preferences.
* Orweb browser : browse web anonymously, Orbot plugin Tor for andriod.
* Andriod Privacy Guard (APG) : sign and encrypt email with K-9 email app.
* ChatSecure : encrypt IM. use OTR protocol. can be  use to chat securely over facebook or google talk on OTR comptible client like Pidgin.
* TextSecure : encrypted SMS app.
* ReadPhone, SlientPhone : encrypt VOIP.
* OSTN (open source telephony network) standard for end-to-end communication. Such as CSipSimple Acrobits, PrivateGSM, Jitsi.

Secure your device.
* enable lock screen password
*  LockScreen Policy app. Disable all widget on lock screen.
* Screen Locker : lock screen before handing the phone to someone else.
* Privacy Master Free fake a crash to prevent app from launching.
* Encrypt device.



Dr Brown
* i-nex tool : hardware and system info in one place.

Linux Kernel
* what does it do?
* kernel architecture : modular design. can be load or unload.

LXF Hotpick
* devcoin :cryptocurrency
* Octave : computation programming language (like Matlab)
* Brackets : free HTML editor from Adobe


Tutorial 
Pipelight plugin : silverlight for streaming work around
Gentoo : install it
Calibre : Build and ebook sever
Deluge : setup a torrent server (use with Raspberry Pi)

Code Academy
PHP : custom website scraping
OCaml : get started

OpenVPN Server and Client Installation and Configuration on Debian 7

From : http://www.tecmint.com/install-openvpn-in-debian/


OpenVPN is a program that route your internet traffic. You can use visit pages under the firewall which might have some limitation,

Understanding LVM

LVM, Demystified
This article explain what is lvm and how to set it up. Good for beginner.

http://www.linuxjournal.com/content/lvm-demystified?page=0,0

LVM command

This page summarize command for lvm. This is very handy.
http://www.datadisk.co.uk/html_docs/redhat/rh_lvm.htm

continuing svnsync from svn hotcopy

svnsync can be a time-consuming process if your revision is big. In this case, I will show how to continue the svnsync from hotcopy


1. Backup current by hotcopy
- svnadmin hotcopy /svn/repos/repos1/ /tmp/repos1

2. Copy data(/tmp/repos1) to new svn server directory /svn/repos/ (svn repository root) 

3. (optional) Upgrade SVN version property in case new SVN sever is  newer than old SVN server
- svnadmin upgrade

4. Initial SVN property for start svnysnc 
- svn propset --revprop -r0 svn:sync-last-merged-rev revno svn://hostname/reposname/
- svn propset --revprop -r0 svn:sync-from-uuid uuid svn://hostname/reposname/
- svn propset --revprop -r0 svn:sync-from-url svn://oldhost/reposname/ svn://hostname/reposname/

5. Sync data from old repos to new repos
- svnsync --non-interactive sync svn://hostname/reposname/

svnadmin dump, svnadmin load

svnadmin dump, svnadmin load
This sub-command can be use for back up and restore svn repository


Dump repository from SVN server
1. Dump SVN database from SVN server
- svnadmin dump /svn/repos/repos1/ | gzip -9 > /tmp/repos1.dump.gz

2. Copy file repos1.dump.gz for back up 

Restore from dumped repository
3. get svn server installed

4. Import SVN data from dump file with this command
- zcat repos1.dump.gz | svnadmin load /svn/repos/newrepos/

Mirroring svn

Mirror SVN server (and replace master server)

1. Install Mirror SVN server

2. Allow svnsync command permission 
- echo '#!/bin/sh' > /svn/repos/repos1/hooks/pre-revprop-change
- chmod +x /svn/repos/repos1/hooks/pre-revprop-change

3. Initial svnsync configure
- svnsync init svn://mirror/repos1/ svn://original/repos1/

 4. Start sync svn data
- svnsync --non-interactive sync svn://mirror

5. Setup schedule to resync svn
- crontab -e 
*/30 * * * * svnsync --non-interactive sync svn://mirror > /dev/null

- /etc/init.d/cron reload

In case you need mirror replace the master
- svnadmin setuuid /svn/repos/repos1/ uuid

replace   uuid from  /svn/repos/repos1/db/uuid 

svn/subversion server installation

Here are a short note for setting subversion server.

1. Install SVN server (subversion)
- apt-get install subversion

2. Create svnuser account
- useradd -m -s /bin/bash svnuser 

3. Create subversion working directory
- mkdir -p /svn/repos/
- chown svnuser.svnuser -R /svn/
- cd /svn/repos/

4. Change user access to svnuser
- su svnuser

5. Create svm repository
- svnadmin create repos1

6. Config repository password
- vi /svn/repos/repos1/conf/svnserve.conf

#####
anon-access = none
auth-access = write
password-db = passwd
#####

repository password file
- vi /svn/repos/repos1conf/passwd

#username and password example
user1 = pass1

- chmod 600 /home/ddsvn/wwwsvn/conf/passwd

7. Start SVN service

#login to svnuser account

- su svnuser

- svnserver -d -r /svn/repos/

8. Set svn start up on boot with user svnuser

- vi /etc/rc.local

#####

su svnuser -c "svnserve -d -r /svn/repos“

#####

APT cacher installation

Running several server with same distribution like ubuntu or debian. It is smart to have repository cache on your network. This can save your bandwidth and time.


Server side
1. Install apt-cacher mandatory package
$  apt-get install apt-cacher

2. Edit apt-cacher configuration
$  vi /etc/apt-cacher/apt-cacher.conf

#####
daemon_addr =
allowed_hosts = /
#####

3. Restart apt-cacher service
$  /etc/init.d/apt-cacher restart


Client side
1. Create proxy files for connect to apt-cacher
$  vi /etc/apt/apt.conf.d/01proxy

#####
Acquire::http::Proxy "http://:3142";
#####


How it work?
1. On client side try to use command apt-get update
2. On APT cacher server check logs file at /var/log/apt-cacher/access.log
to see client connection


Reference :
http://www.debuntu.org/how-to-set-up-a-repository-cache-with-apt-cacher/
https://help.ubuntu.com/community/Apt-Cacher-Server

Replace failure harddisk on SW raid 1

In example, Server build software raid 1 with two harddisk, sda and sdb. In this case, sdb fail. Below step show how to replace new harddisk on mdadm raid configuration.

1. Check sdb partition member on raid group  
$ cat /proc/mdstat

####################
 root@raid:/# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sdb6[2] sda6[0]
      6917056 blocks super 1.2 [2/2] [UU]

md0 : active raid1 sdb1[2] sda1[0]
      487104 blocks super 1.2 [2/2] [UU]

unused devices:
####################
You will see sdb1 was a member of md0 and sdb6 was a member of md1

2. Mark sdb partition to failure
$ mdadm --manage /dev/md0 --fail /dev/sdb1
$ mdadm --manage /dev/md1 --fail /dev/sdb6

####################
root@raid:/# mdadm --manage /dev/md0 --fail /dev/sdb1
mdadm: set /dev/sdb1 faulty in /dev/md0

root@raid:/# mdadm --manage /dev/md1 --fail /dev/sdb6
mdadm: set /dev/sdb6 faulty in /dev/md1

root@raid:/# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sdb6[2](F) sda6[0]
      6917056 blocks super 1.2 [2/1] [U_]

md0 : active raid1 sdb1[2](F) sda1[0]
      487104 blocks super 1.2 [2/1] [U_]

unused devices:

root@raid:/#
####################
You will see the member of md0 and md1 change to [2/1] [U_]

3. Remove sdb1 and sdb6 from raid group
$ mdadm --manage /dev/md0 --remove /dev/sda1
$ mdadm --manage /dev/md1 --remove /dev/sdb6

####################
root@raid:/# mdadm --manage /dev/md0 --remove /dev/sdb1
mdadm: hot removed /dev/sdb1 from /dev/md0
root@raid:/# mdadm --manage /dev/md1 --remove /dev/sdb6
mdadm: hot removed /dev/sdb6 from /dev/md1

root@raid:/# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sda6[0]
      6917056 blocks super 1.2 [2/1] [U_]

md0 : active raid1 sda1[0]
      487104 blocks super 1.2 [2/1] [U_]

unused devices:

####################
You will see partition sdb1 and sdb6 already remove from raid group

4. Shutdown and change new harddisk

4.1 If new harddisk have old data you need to clear data first
$ dd if=/dev/zero bs=1M count=1 of=/dev/sdb; sync

5. After turn on check you new harddisk already install completely 
$ fdisk -l /dev/sdb

####################
root@raid:/# fdisk -l /dev/sdb

Disk /dev/sdb: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders, total 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sdb doesn't contain a valid partition table
root@raid:/#
####################

6. Before we add new harddisk to raid member group we need to clone partition from sda and confirm partition must be same as sda
$ sfdisk -d /dev/sda | sfdisk /dev/sdb

####################
root@raid:/# sfdisk -d /dev/sda | sfdisk /dev/sdb
Checking that no-one is using this disk right now ...
Warning: extended partition does not start at a cylinder boundary.
DOS and Linux will interpret the contents differently.
OK....
...
root@raid:/# fdisk -l /dev/sdb

Disk /dev/sdb: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders, total 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *        2048      976895      487424   fd  Linux raid autodetect
/dev/sdb2          978942    16775167     7898113    5  Extended
/dev/sdb5          978944     2930687      975872   82  Linux swap / Solaris
/dev/sdb6         2932736    16775167     6921216   fd  Linux raid autodetect
####################

7. Add sdb partition to raid group
$ mdadm --manage /dev/md0 --add /dev/sdb1
$ mdadm --manage /dev/md1 --add /dev/sdb6

####################
root@raid:/# mdadm --manage /dev/md0 --add /dev/sdb1
mdadm: added /dev/sdb1
root@raid:/# mdadm --manage /dev/md1 --add /dev/sdb6
mdadm: added /dev/sdb6
root@raid:/# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdb1[2] sda1[0]
      487104 blocks super 1.2 [2/2] [UU]

md1 : active raid1 sdb6[2] sda6[0]
      6917056 blocks super 1.2 [2/1] [U_]
      [>....................]  recovery =  1.8% (130816/6917056) finish=0.8min speed=130816K/sec

unused devices:
####################

8. Install grub on sdb partition 
$ grub-install /dev/sdb

####################
root@raid:/# grub-install /dev/sdb
Installation finished. No error reported.
root@raid:/#
####################

Remark: You can uninstall grub by:
$ dd if=/dev/zero of=/dev/sdb bs=446 count=1

9. For confirm grub is install on partition, it have two ways
- by command 
$ dd if=/dev/sdb  bs=512  count=1 2>/dev/null | hexdump -C

the result you will found GRUB string on output, it mean you grub already install on sdb correctly

- by script "Boot Info Script", is develop by ghulselmans, you can download on URL

http://sourceforge.net/projects/bootinfoscript/

after download and extract just run ./bootinfoscript it will show grub information in file RESULTS.txt

10. That all for change new harddisk but wait It still have SWAP partition remain, In my case I make SWAP partition 1 GB on sda5 and sdb5 but after change disk found SWAP partition of sdb5 not activate.

####################

root@raid:/# free -m

             total       used       free     shared    buffers     cached

Mem:           495         89        406          0         10         39

-/+ buffers/cache:         40        455

Swap:          952          0        952

root@raid:/#

####################

11. Because new harddisk drive the UUID of drive will change we need to make SWAP and change the UUID in fstab file

$ mkswap /dev/sdb5

####################

root@raid:/# mkswap /dev/sdb5

Setting up swapspace version 1, size = 975868 KiB

no label, UUID=815d087f-0875-494a-a947-2220fd14a12d

root@raid:/#

####################

12. Copy you new UUID replace in /etc/fstab 

In my case change from 

# swap was on /dev/sdb5 during installation

UUID=0f049d6d-506c-4bdb-9fec-1a6b808fbb65 none            swap    sw              0       0

to

# swap was on /dev/sdb5 during installation

UUID=815d087f-0875-494a-a947-2220fd14a12d none            swap    sw              0       0

13. Activate swap partition sdb5

$ swapon /dev/sdb5

####################

root@raid:/# swapon /dev/sdb5

root@raid:/# free -m

             total       used       free     shared    buffers     cached

Mem:           495         93        402          0         10         42

-/+ buffers/cache:         40        455

Swap:         1905          0       1905

root@raid:/#

####################



From :
http://www.liberiangeek.net/2012/07/how-to-find-where-grub-is-installed-in-ubuntu/
http://www.howtoforge.com/replacing_hard_disks_in_a_raid1_array