Restore OSX Timemachine backup files in Linux
copy the script from
https://gist.github.com/magicoli/283785bdf21ebafd2202
chmod +x copy-from-time-machine.sh
~/Documents/copy-from-time-machine.sh /media/popoy/Seagate/Backups.backupdb/Popoy’s\ MacBook\ Pro/Latest/Macintosh\ HD/Users/popoy/Downloads ~/Documents/Downloads
RaspberryPi+raspbian+ratpoison
Setting up a web kiosk system using raspberrypi+raspbian+ratpoison
This instruction assumes that you already installed raspbian on your SD card
Installing required packages
sudo apt-get update
sudo apt-get ratpoison
sudo apt-get chromium
sudo apt-get x11vnc
sudo apt-get install x11-xserver-utils
=====
Start user pi at startup
=====pi@raspberrypi:~$ grep pi /etc/inittab 1:2345:respawn:/bin/login -f pi tty1
/dev/tty1 2>&1
pi@raspberrypi:~$ cat /home/pi/.bash_profile
if [ -z "$DISPLAY" ] && [ $(tty) == /dev/tty1 ]; then
startx
fi
Set ratpoison's config file
pi@raspberrypi:~$ cat /home/pi/.xinitrc exec ratpoison
pi@raspberrypi:~$ cat /home/pi/.ratpoisonrc banish exec xset s off exec xset -dpms exec unclutter -root exec x11vnc -loop exec /usr/bin/chromium --kiosk http://www.penoycentral.net
Remotely connec thru vnc
vncviewer raspberrypi.local
Enable DNS queries in BIND
# rndc querylog
Query logs should be logged on /var/log/messages
To turn off
# rndc querylog
ref: http://www.cyberciti.biz/faq/howto-enable-dns-linux-unix-server-logging/
bash: scp: command not found
scp file.rar root@192.168.11.60:/var/tmp/
root@192.168.11.60's password:
bash: scp: command not found
lost connection
i forgot that i have done a minimal server install on the receiving end. installing openssh-clients solve the problem
Vi/VIM
To insert characters on the beginning of a line. Example, insert // from line 1 to 10
:1,10s!^!//!
Sample in creating folding in vim. Insert #{{{ text here #}}} provided everything was properly setup on vimrc
~/workspace/puppetworks $ cat site.pp
node 'chrisp.lab.local' {#{{{
}#}}}
pressing zc will close the folded texts
+-- 6 lines: node 'chrisp.lab.local' {#----------------------------------------------------------------------------
ref: http://www.linux.com/learn/tutorials/442438-vim-tips-folding-fun
Mercurial hgwebdir on CentOS 6
Note this setup is unsecured and just for the purpose of having my own lab svn repo.
Install mercurial on your server
yum install mercurial
Setup the mercurial site on apache
mkdir /var/www/cgi-hg
cp /usr/share/doc/mercurial-1.4/hgwebdir.cgi /var/www/cgi-hg/
chmod +x /var/www/cgi-hg/hgwebdir.cgi
Create the hgweb.config
/var/www/cgi-hg/hgweb.config
[paths]
#VIRTUAL_PATH = /REAL/PATH
#myproject = myproject
lab = /srv/hg
Reload apache
service httpd reload
Make sure everything has the right permission on selinux or you can temporarily disable selinux
Your site now is accessible thru http://servername/hg
To test push functionality,you might try to disable ssl and allow push to all
/srv/hg/.hg/hgrc
[web]
allow_push = *
push_ssl = false
Ref:
http://mercurial.selenic.com/wiki/RHEL4HgWebDirSetup
http://mercurial.selenic.com/wiki/PublishingRepositories
Quick mail sending test
penoy@fedora:~$ mail -s "test sending mail from nix server" penoy@example.com < /dev/null
Changing Timezone in RHEL/Centos
This is one way of changing your server timezone and resync on the ntp server
service ntpd stop
cp /usr/share/zoneinfo/Asia/Singapore /etc/localtime
ntpdate
service ntpd start
more info: http://www.redhat.com/advice/tips/timezone.html
remove host key under known_hosts
Normally after a server rebuild you will receive a warning that the host identification has changed
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
One solution is to remove the offending host key
ssh-keygen -f "/home/chris/.ssh/known_hosts" -R ip-address-of-the-host
RHCSA/RHCE Red Hat Linux Certification Practice Exams with Virtual Machines (Exams EX200 & EX300)
vmnetcfg in VMware Player running in Fedora 16
where is vmnetcfg in VMware Player running in Fedora 16?
It is found under:
/usr/lib/vmware/bin/vmware-netcfg
Unable to set size of tmpfs in /etc/fstab RHEL6.2
Resized tmpfs space in /etc/fstab to 4g
tmpfs /dev/shm tmpfs size=4096m 0 0
After reboot, size still on 2G
[root@OEL1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_oel1-lv_root
16G 3.8G 11G 27% /
tmpfs 2.0G 0 2.0G 0% /dev/shm
/dev/sda1 485M 51M 409M 12% /boot
Looks like a bug on RHEL6
https://www.redhat.com/archives/rhelv6-list/2011-February/msg00081.html
[root@OEL1 ~]# mount -o remount /dev/shm
[root@OEL1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_oel1-lv_root
16G 3.8G 11G 27% /
tmpfs 4.0G 0 4.0G 0% /dev/shm
/dev/sda1 485M 51M 409M 12% /boot
[root@OEL1 ~]# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.2 (Santiago)
OpenWRT Backfire (10.03.1-RC6, r28680) Linksys WRT54GL
My Linksys WRT54GL wireless router running on OpenWRT
Laptop overheat in Fedora 16
After installing Fedora 16 on my laptop(or any RH flavors) i noticed a huge temperature difference when running Windows 7 vs Fedora/RH. Definitely, my laptop temperature is high even in idle.
Followed a workaround as discussed in Bugzilla 702953 by setting the GPU power to mid instead of using the max power
[root@fedora ~]# acpi -t
Thermal 0: ok, 78.0 degrees C
Now set the GPU power to mid
[root@fedora ~]# echo mid > /sys/class/drm/card0/device/power_profile
Temperature goes down instantly
[root@fedora ~]# echo `date` && acpi -t
Sun Dec 4 06:18:35 SGT 2011
Thermal 0: ok, 71.0 degrees C
[root@fedora ~]# echo `date` && acpi -t
Sun Dec 4 06:30:05 SGT 2011
Thermal 0: ok, 68.0 degrees C
One alternative way of monitoring temperature is by the use of lm_sensors
[root@fedora ~]# sensors
acpitz-virtual-0
Adapter: Virtual device
temp1: +83.0°C (crit = +103.0°C)
radeon-pci-0100
Adapter: PCI adapter
temp1: +84.0°C
Im running ATI Radeon HD5730 video card
Red Hat Certified Engineer
It has been a long day for me.. RHCSA exam in the morning and RHCE exam in the afternoon. Finally after months of self study and 4 days on the rapid track course, i nailed both exam.
Pretty much to say that i'm so proud on the cert. This is not the type of exam that you will just choose among the multiple choice or configure in a simulated environment. It will test your knowledge on how well you understood Redhat.
On future takers, i advised you to know the exam objectives inside and out. SELinux looks like intimidating at first, but as soon as you understand how it works,it will be a piece of cake for you :)
Materials/books used
RHCSA/RHCE Red Hat Linux Certification Study Guide (Exams EX200 & EX300), 6th Edition (Certification Press) -- Michael Jang
Highly recommend!!! Comes with a CD with pdfs and labs exams at the end of every chapter. My fav source of info for the exam.
Hands-on Guide to the Red Hat® Exams: RHCSA™ and RHCE® Cert Guide and Lab Manual (Certification Guide) -- Damian Tommasino
Lots of errors, but hey, as soon as you pointed the errors in the book, it just shows that you know your stuffs. Used to counter check configs and setup.
RH300 RHCE Rapid Track course
Final review for the exam. It cost much but highly recommended also. It guides me and helps to fill in the gaps on what i have learned already on my home lab. Before taking the course, i advised that you first do your home work. Learn the exam objectives, build your own home lab, simulate the configs as advised on Michael and Damian's book. In this way when you attend the course, you can ask all the questions that you have on your instructor. This is fast-paced course so make full use of it.
texastwister/OpenRHCE - GitHub - This is a beast study guide. I used this as a last minute review before taking the exam. Reading the whole week while in the train :) Highly recommended also
As always, we signed the Non-disclosure Agreement so i will not divulge anything specific about the exam. I might update this blog,but will not be on the RHCE exam specific anymore.
Study!!! study!!!! study!!!!! lab!!!! lab!!!! lab!!!! simulate!!!! simulate!!!! and always follow the KISS principle..
reposted from RHCSA/RHCE Exam notes August 26 2011
Playing with Logical Volume Manager
Initialize disk using pvcreate
[root@rhel01 ~]# pvcreate /dev/sda1
Physical volume "/dev/sda1" successfully created
Create volume group lab_group1
[root@rhel01 ~]# vgcreate lab_group1 /dev/sda1
Volume group "lab_group1" successfully created
In this sample i created 10MB of logical volume mount to /mnt
[root@rhel01 ~]# lvcreate -L 10M lab_group1 -n lab01
Rounding up size to full physical extent 12.00 MiB
Logical volume "lab01" created
[root@rhel01 ~]# mkfs.ext4 /dev/lab_group1/lab01
mke2fs 1.41.12 (17-May-2010)
[root@rhel01 ~]# mount /dev/lab_group1/lab01 /mnt[root@rhel01 ~]# df -h /mntFilesystem Size Used Avail Use% Mounted on/dev/mapper/lab_group1-lab0112M 1.2M 10M 11% /mnt
Extending Logical Volume using new disk
Initialize new disk
[root@rhel01 ~]# pvcreate /dev/sdb1
Wiping software RAID md superblock on /dev/sdb1
Physical volume "/dev/sdb1" successfully created
Extend lab_group1 volume group
[root@rhel01 ~]# vgextend lab_group1 /dev/sdb1
Volume group "lab_group1" successfully extended
[root@rhel01 ~]# vgdisplay lab_group1
--- Volume group ---
VG Name lab_group1
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 56.00 MiB
PE Size 4.00 MiB
Total PE 14
Alloc PE / Size 3 / 12.00 MiB
Free PE / Size 11 / 44.00 MiB
VG UUID o8kB09-P20F-QLFx-UmPE-5BB5-mlu9-o867qV
Extend logical volume lab01
[root@rhel01 ~]# lvextend -L +10M /dev/lab_group1/lab01
Rounding up size to full physical extent 12.00 MiB
Extending logical volume lab01 to 24.00 MiB
Logical volume lab01 successfully resized
[root@rhel01 ~]# df -h /mnt
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/lab_group1-lab01
12M 1.2M 10M 11% /mnt
[root@rhel01 ~]# resize2fs /dev/lab_group1/lab01
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/lab_group1/lab01 is mounted on /mnt; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 1
Performing an on-line resize of /dev/lab_group1/lab01 to 24576 (1k) blocks.
The filesystem on /dev/lab_group1/lab01 is now 24576 blocks long.
[root@rhel01 ~]# df -h /mnt
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/lab_group1-lab01
24M 1.2M 22M 5% /mnt
LVM: Can't remove open logical volume
[root@rhel01 /]# lvremove /dev/lab_group/lab01Can't remove open logical volume "lab01"Command failed
[root@rhel01 /]# dmsetup info -c lab_group-lab01Name Maj Min Stat Open Targ Event UUIDlab_group-lab01 253 7 L--w 0 1 0 LVM-XHpst6rC31EOIHxjWAp6CfbCBUIcF p1uqjWa6RINr32OZVWF0pdnfaal8DKoUZGH
[root@rhel01 /]# lvremove /dev/lab_group/lab01Can't remove open logical volume "lab01"
[root@rhel01 /]# dmsetup remove lab_group-lab01
[root@rhel01 /]# lvremove /dev/lab_group/lab01Logical volume "lab01" successfully removed
Oracle Certified Sytem Admin for Solaris 10
Passing score:63
Your Score : 70
Result: PASS
Whoa i barely passed Oracle Certified System Admin for Solaris 10 (310-202) Part 2 exam. Caught off guard on LDAP and I just hate Jumpstart questions. Already convinced myself that i failed the exam because of the low percentile per topic, but what a relief when the examiner handed me the test printout with the word PASS.
Have to relax first this weekend before i go back to my labs.. hopefully RHCE eh :)
/sbin/loader hangs while installing RHEL 6 in Virtualbox
running install...
running /sbin/loader
Hit tab key in Grub and enter this at the end of the line
linux apm=off acpi=off pci=noacpi
Referrence http://www.samlesher.com/category/fedora