Tagged: my_thoughts

Installing Arch Linux: LVM on top of an encrypted partition [[UPDATED]]

Years back, I was using Arch Linux on my notebook but gave up at some point after upgrading Arch Linux made my notebook unbootable. After some distro hoppings, I settled down with Debian Linux and it has been my friend since then. But now, out of a whim, I decided to give another try on Arch.

I'll be installing Arch Linux on the same notebook and I wanted the encryption on a disk/partition like before. I looked around some options from the Arch Linux Wiki. I read up on LVM on LUKS, LUKS on LVM, and Plain dm-crypt and decided to go with LVM on LUKS again. One of benefits for LUKS on LVM is that it can have encrypted volumes span multiple disks. It's nice but I don't need it since there is only one disk for the notebook. Plain dm-crypt can encrypt an entire disk and this is nice and ideal but having a USB flash memory around is a bit overkill for me. So, I'll stick with LVM on LUKS again.

I then followed my old post, Installing Arch Linux: LVM on top of an encrypted partition. What do you know? The information on that page was not wrong but was a bit confusing or hard to follow (not to mention about the number of typos. Sheesh!). So, I decided to re-do the whole steps, including the base installation of Arch Linux on LVM. Most of the information here will be duplicates from old one but please bare with me.

Information below is gathered mostly from the Arch Linux Wiki page and changed here and there for my liking. This information below is solely used for my purpose and may not be suitable for others.

Erasure of the Hard Disk:

Information (data) on a Hard Drive is written in chunk here and there. Re-partitioning or reformatting a disk does not really removes (erase) the data. It merely remove the system structure that used to identify where the original data was located. This leaves the actual data on a disk.

To securely erase a disk, you could either:

  • Fill with zeros
  • Fill with random bits

Both methods overwrite data on a disk but the first one fill with zero's leaving easily (to some extent) identify where the encrypted data ends. So, I follow the second method. # dd if=/dev/urandom of=/dev/<drive> bs=1M Just to be warned, this takes a long, long time.

Partitioning a Disk:

There is a way to encrypt the /boot partition with GRUB (for details, see Pavel Kogan's blog), but for simplicity, I'll stick with having the /boot partition separated from the encryption and LVM. # fdisk /dev/sda

Partition Layout:
/dev/sda1 -> /boot (bootable) - 300MB should be enough.
/dev/sda2 -> LVM (8e) - the rest of the disk

Configuring LUKS:

cryptsetup is used to interface with LUKS for formatting, mounting and unmounting encrypted partition.

First make sure the device mapper kernel module is installed: # modprobe dm-mod

Then format it as an encrypted LUKS partition: # cryptsetup --cipher aes-xts-plain64 --key-size 512 --hash sha512 luksFormat /dev/sda2

  • --cipher: defines the cipher type
  • --key-size: defines the key size
  • --hash sha512: hash algorithm used for key derivation.

It looks like AES cipher in XTS mode (XTS-AES) is most popular these days.

Unlocking/Mapping LUKS partition with the Device Mapper:

To access the encrypted volume, It needs to be unlocked. # cryptsetup open --type luks /dev/sda2 lvm


Create a physical volume (encrypted volume) and a group volume. # lvm pvcreate /dev/mapper/lvm # lvm vgcreate lvmvg /dev/mapper/lvm

Create logical volumes on this new volume group. # lvm lvcreate -L 10G -n root lvmvg # lvm lvcreate -L 500M -n swap lvmvg # lvm lvcreate -l 100%FREE -n home lvmvg

Format the filesystems on each logical volume. # mkfs.ext4 /dev/mapper/lvmvg-root # mkfs.ext4 /dev/mapper/lvmvg-home # mkswap /dev/mapper/lvmvg-swap

Mount the filesystems. # mount /dev/mapper/lvmvg-root /mnt # mkdir /mnt/home # mount /dev/mapper/lvmvg-home /mnt/home # swapon /dev/mapper/lvmvg-swap

Prepare the boot partition. # mkfs.ext2 /dev/sda1 # mkdir /mnt/boot # mount /dev/sda1 /mnt/boot

Configure Wireless Network:

Network connection needs to be configured before the installation can take a place. Since my notebook uses WiFi, I need to configure wireless network.

Check for the network interface and whether udev has loaded the driver. # iwconfig -------------------- eth0 no wireless extensions. lo no wireless extensions. wlan0 IEE 802.11bgn ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=14 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:on

It looks like wlan0 is available.

Interface activation:

Not required for mine but here is how to activate # ip link set wlan0 up

Access point discovery:

I know my network information like ESSID, Encryption key, etc..., but here is how to list available access points # iwlist wlan0 scan | less

Or, for the new netlink interface # iw dev wlan0 scan | less

Association to the access point

Now a configuration file, /etc/wpa_supplicant.conf, needs to be created for my access point. # vi /etc/wpa_supplicant.conf -------------------- ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=wheel eapol_version=1 ap_scan=1 fast_reauth=1

These options are explained in /etc/wpa_supplicant/wpa_supplicant.conf

Append the passphrase and PSK to the file # wpa_passphrase SSID_NAME "PASSPHRASE" >> /etc/wpa_supplicant.conf

Manual connection:

The WiFi interface should be up by the earlier command ip link set wlan0 up, so now tell wpa_supplicant the driver (wext - Linux Wireless EXTensions), the SSID specified in /etc/wpa_supplicant.conf and the wireless interface. # wpa_supplicant -B -Dwext -i wlan0 -c /etc/wpa_supplicant.conf

  • -B : Run in the background
  • -D : Driver information. Default is WEXT
  • -i : Wireless interface
  • -c : Configuration file

Request an IP address to DHCP server. # dhcpcd wlan0

Check assigned IP address. # ip addr show wlan0 wlan0: mtu 1500 qdisc mq state UP qlen 1000 link/ether 00:00:00:00:00:00: brb ff:ff:ff:ff:ff:ff inet brb scope global wlan0 inet6 fe80::ffff:ffff:ffff:ffff/64 scope link valid_lft forever preferred_lft forever

Select installation mirror:

Before installing, you may want to edit /etc/pacman.d/mirrorlist such that your preferred mirror is first. This copy of the mirrorlist will be installed on your new system by pacstrap as well, so it's worth getting it right.

Install the base system and other package groups:

The base system is installed using the pacstrap script. pacstrap is a script that installs packages to the specified new root directory. If no packages are given, pacstrap defaults to the "base" group.

Required X Window Systems packages for openbox will be installed in post-installation configuration.

The system uses wireless network, so install the required wireless network packages. # pacstrap /mnt base base-devel wireless_tools wpa_supplicant wpa_actiond


Let's configure the primary configuration files.

Generate an fstab file:

The fstab file contains static filesystem information. It defines how storage devices and partitions are to be mounted and integrated into the overall system. It is read by the mount command to determine which options to use when mounting a specific device or partition.

Check the resulting file afterwards, especially watch for the swap entry. # genfstab -p /mnt >> /mnt/etc/fstab # vi /mnt/etc/fstab -------------------- ... /dev/mapper/lvm-swap none swap defaults 0 0

Chroot into the system (Change root into the new system):

# arch-chroot /mnt

Editing /etc/rc.conf:

/etc/rc.conf is the configuration file for Arch's initscripts. Some of options in this file has been obsolete and they now have own configuration files (ex: hostname, etc...). /etc/rc.conf still configures daemons to start during boot-up and some networking and storage information.

Since LVM is used on this system, I need to enable it so that the kernel knows about it.

# vi /etc/rc.conf -------------------- USELVM="yes"


Configuring hostname requires updating two files, /etc/hostname and /etc/hosts

Add hostname in /etc/hostname # cat > /etc/hostname archy64 ^D

Add hostname in /etc/hosts # vi /etc/hosts -------------------- localhost.localdomain localhost archy64 ::1 localhost.localdomain localhost archy64

Console fonts and keymap:

The console, meaning a terminal running with no X Window System, uses the ASCII character set as the default.

A console font is limited to either 256 or 512 characters. The fonts are found in /usr/share/kbd/consolefonts/.

Keymaps, the connection between the key pressed and the character used by the computer, are found in the subdirectories of /usr/share/kbd/keymaps/ # cat > /etc/vconsole.conf KEYMAP=us FONT= FONT_MAP= ^D

  • KEYMAP - the default (us) is ok
  • FONT - the default (blank) is ok
  • FONT_MAP - the default (blank) is ok


Available time zones and subzones can be found in the /usr/share/zoneinfo/<Zone>/<SubZone> directories.

Create a symlink /etc/localtime to zone file. # ln -s /usr/share/zoneinfo/US/Eastern /etc/localtime


Choose the locale(s) from /etc/locale.gen and uncomment them. # vi /etc/locale.gen -------------------- en_US.UTF-8 UTF-8 -------------------- # locale-gen

Setting up system-wide locale:

# cat > /etc/locale.conf LANG=en_US.UTF-8 LC_TIME=en_US.UTF-8 ^D

Set the LANG variable for the ramdisk creation # export LANG=en_US.UTF-8

Hardware clock time:

It's recommended to use UTC. # hwclock --systohc --utc

Create an initial ramdisk environment:

Configure /etc/mkinitcpio.conf for encryption and LVM by adding encrypt lvm2 (in this order) in the HOOKS section before filesystems so that the kernel will find LVM volumes at boot time. # vi /etc/mkinitcpio.conf -------------------- HOOKS="...encrypt lvm2 filesystems..."

Now generate the kernel image. # cd /boot # mkinitcpio -p linux

Install and configure a bootloader:

# pacman -S grub-bios os-prober # grub-install --recheck /dev/sda

Create a grub configuration file. # grub-mkconfig --output /boot/grub/grub.cfg


Add cryptdevice=/dev/sda2:lvmvg between root=... and ro in the line starts with linux. This needs to be done for "Arch Linux" and "Arch Linux Fallback". # vi /boot/grub/grub.cfg -------------------- linux /boot/vmlinuz-linux root=/dev/mapper/lvmvg-root cryptdevice=/dev/sda2:lvmvg ro quiet

Root password:

Set the root password now. # passwd


Exit from chroot, unmount the partitions, close the device and reboot. # exit # umount -R /mnt/boot # umount -R /mnt # cryptsetup close lvm # reboot

After rebooting, it should ask you for a passphrase like below:


Updating the system:

Sync, refresh, and upgrade the entire new system. # pacman -Syu (or pacman --sync --refresh --sysupgrade)

Pacman will now download a fresh copy of the master package list from the server(s) defined in /etc/pacman.conf and perform all available upgrades.

Note: If you get following errors after executing above statement, it most likely you don't have dhcpcd is not running or your network setting is not correct.

error: failed retrieving file '...' from ... : Could not resolve host: ...

Pacman output is saved in /var/log/pacman.log

Adding a user:

Now add a normal user account for daily tasks # useradd -m -g users -G audio,games,log,lp,optical,power,scanner,storage,video,wheel -s /bin/bash ubyt3m3

Set a password for ubyt3m3 # passwd ubyt3m3

X Window System:

The X Window System (commonly X11, or X) is a networking and display protocol which provides windowing on bitmap displays. It provides the standard toolkit and protocol to build graphical user interfaces (GUIs).

Before installing the X11, try to see what kind of video card you have # lspci | grep -e VGA -e 3D

Then install the base Xorg packages using pacman. # pacman -S xorg-server xorg-xinit xorg-server-utils

During the installation, it'll ask you for the type of libgl. Use below information based on the type of video card you have (returned value from the lspci command above), choose a proper driver.

xf86-video-amdgpu ... mesa-libgl
xf86-video-ati ... mesa-libgl
catalyst ... catalyst-libgl

xf86-video-intel ... mesa-libgl

xf86-video-nouveau ... mesa-libgl
nvidia ... nvidia-libgl
nvidia-340xx ... nvidia-340xx-libgl
nvidia-304xx ... nvidia-304xx-libgl

Install video driver:

My system came with ATI Graphics Card, so install the open source raden driver. # pacman -S xf86-video-ati

Install input driver:

Since this install is for notebook, following package is needed for touchpad. # pacman -S xf86-input-synaptics

Are you installing Arch Linux as VirtualBox Guest?

If you are like me, you'd test the installation of OS or software on a virtual system before actually installing on main systems. I use VirtualBox for that. In order for Arch Linux to run X11 within the VirtualBox guest environment, VirtualBox Guest Additions need to be installed. # pacman -S virtualbox-guest-utils

After executing above command, it'll ask you for guest modules. Choose virtualbox-guest-modules-arch if you used linux kernel when you ran mkinitcpio -p linux during the configuration period. For other modules, use virtualbox-guest-dkms

Loading the VirtualBox kernel modules:

Before getting X11 work on the guest environment, VirtualBox kernel modules must be loaded. To do this automatically, enable the vboxservice service. # systemctl enable vboxservice

Load the modules # modprobe -a vboxguest vboxsf vboxvideo

Testing X:

Install the default environment. # pacman -S xorg-twm xorg-xclock xterm


Install a set of TrueType fonts, as only unscalable bitmap fonts are included by default. DejaVu is a set of high quality. # pacman -S ttf-dejavu

Now, that's a very base system. If you are interested in installing Openbox, you can follow steps in my post, Openbox (w/ Arch Linux).

That's all!

/usr/lib/libjpeg.so: could not read symbols: File in wrong format collect2: error: ld returned 1 exist status

I was in need of installing software on my Slackware64 14.1 on the other day and got a following error message: ... /bin/sh ../libtool --tag=CC --mode=link gcc -Wall -Wstrict-prototypes -Wmissing-prototypes -O2 -fPIC -module -avoid-version -o export_jpg.la -rpath /usr/lib64/transcode export_jpg_la-export_jpg.lo -L/usr/lib -ljpeg -lm -lm -lz -ldl libtool: link: gcc -shared -fPIC -DPIC .libs/export_jpg_la-export_jpg.o -L/usr/lib /usr/lib/libjpeg.so -lm -lz -ldl -O2 -Wl,-soname -Wl,export_jpg.so -o .libs/export_jpg.so /usr/lib/libjpeg.so: could not read symbols: File in wrong format collect2: error: ld returned 1 exit status make[2]: *** [export_jpg.la] Error 1 make[2]: Leaving directory `/tmp/SBo/transcode-1.1.7/export' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/tmp/SBo/transcode-1.1.7' make: *** [all] Error 2

From the error message, I can tell that it has something to do with linker and libraries, perhaps using 32-bit library on my 64-bit Slackware. I checked the LDFLAGS variable in its MakeFile and it was empty.

Ok, is there a way to force the compiler to use 64-bit libraries with SlackBuild scripts?

YES! A variable can be passed to SlackBuild script. To force the SlackBuild script to use 64-bit library, simply add variable with its value before executing a SlackBuild script.

$ LDFLAGS="-L/usr/lib64" ./[SlackBuildScript_name]

VoilĂ . The compilation went through without any more errors!

Disclaimer: The information in this site is the result of my researches in the Internet and of my experiences. It is solely used for my purpose and may not be suitable for others. I will NOT take any responsibility of end result after following these steps (although I will try to help if you send me your questions/problems).

That's all!

A Happy New Year, 2016!

This is the first blog entry in 2016.

Year 2015 was eventful year for me in many ways. They kept me busy (too busy time to time) but they also kept me going forward and got me through another year. Can't complain.

One regret that I have would be there were only a few posts I made last year despite the fact that I said I would keep up with posting entries at the beginning of the year. Hmm... I hope I'll do better job this year.

Well, thank you for those who visited my blog and those who took your precious time to leave me comments! You are the best!

I wish everyone a happy, peaceful, prosperous and productive new year!

That's all!

Happy New Year to You!

Happy New Year, 2015!

I can't believe yet another year passed by and my blog is still up and running ;P Put some jokes aside, I didn't expect myself posting new articles consistently (well almost consistently). This is all because encouraging comments some visitors leave for me. Honestly, if no one reads my blog, even though I said at the beginning this blog was only meant as some notes for myself, I wouldn't have been able to continue this long. So let me say this again... Thank you!

For my New Year's resolutions, I'd like to keep my blog up and running for another year with more notes to myself that would be informative/helpful to others.

That's all!

Copying Files From Android Kitkat (4.4.4) to Slackware

I didn't know until I tried myself but when I connected my Samsung Galaxy Note 4 to my slacky64 (Slackware Linux) via USB, I no longer had an option to connect it as USB Mass Storage (UMS) like it did with other flash drives. In stead, it gave me two options: MTP and PTP. Hmm... what the heck are these?


Apparently, the old way of accessing the storage device had several drawbacks. One being how it was making its storage partition available to foreign systems. Whenever another system accessed the phone's storage area, it needed exclusive access to there, which means the entire storage partition was dedicated to that system and as long as that system was accessing there, the phone itself couldn't access any files or apps stored in that area. Also, this could easily mess up (or corrupt) the storage partition.

Another reason was the type of its file system. Because its storage partition needed to be available to various systems, mostly for Windows devices, it was formatted as the FAT file system (Duh...). FAT is an older and slower file system without the concept of file ownership. Not to mention Microsoft holds patents for which they demand royalties from OEM's for long file name support on the FAT file system, etc...

So what are MTP and PTP?

MTP (Media Transfer Protocol) is a subset of PTP (Picture Transfer Protocol) communication protocols that allow transferring media files from and to portable devices. These protocols have been around for a while but they are new to Android. They are considered better solutions to the problems UMS had. When a foreign system accesses the phone via MTP, it sends queries to Android and Android returns with the list of files requested. Then it downloads files. This allows access to file levels rather than exclusively opens up the entire storage portion and also allows Android choose which files to present.

This also enables Android format its storage device with ext3/ext4 or any other file systems - no longer limited to FAT!

PTP works the similar way and is mostly used by digital cameras.

For more information, please refer to Android USB Connections explained MTP, PTP, and USB Mass Storage

Now, some terminologies are out of the way, I tried transferring some photos from my Note 4 to slacky64 using MTP. Hm? It's very slow loading photos and it's even slower transferring them. Also, after photos were copied over, not only were their timestamp changed to current date and time instead of date and time taken but my photo viewer program also couldn't display them. That's not good...

I was hoping PTP would work better but no luck. It was even worse; I couldn't even get photos listed in my file manager.

Now, I went on a hunt for better ways to transfer photos.

I tried sftp and scp (with an option to retain the original timestamp) but its process kept dying on me while in the middle of transferring files.

I was kind of frustrated with this. Then, I found dukto in Google Play. It had good reviews and high rating points. I was a bit concerned about this program needing be installed on all devices, but, what the heck, as long as it'll transfer photos, I would be happy at this point.

Installation on the Android device was breeze. There were some extra steps needed to install it on my Slackware system because dukto was available in binary packages for CentOS, Fedora, OpenSUSE, RHEL, and Ubuntu and no source. This means the rpm package needs to be converted to the tgz format with the rpm2tgz command.

Converting rpm with rpm2tgz

Slackware comes with a handy utility to convert rpm files to tgz files. All you need is to run rpm2tgz with rpm file: # cd /tmp # rpm2tgz dukto-6.0-13.1.x86_64.rpm ... Slackware package /tmp/dukto-6.0-13.1.x86_64.tgz created # installpkg /tmp/dukto-6.0-13.1.x86_64.tgz Verifying package dukto-6.0-13.1.x86_64.tgz. Installing package dukto-6.0-13.1.x86_64.tgz: PACKAGE DESCRIPTION: Package dukto-6.0-13.1.x86_64.tgz installed. #

VoilĂ ! The conversion and installation went successful. To run the program, execute dukto: $ dukto


Transferring Files

To transfer file from the Android device to PC:

  1. Open dukto on both devices
  2. On the Android device, click on the icon you want to send your files
  3. Choose Send some files and folders if you are sending files
  4. Locate files you wish to send
  5. Check files
  6. Click on the Send icon

Once selected files have been transferred, the confirmation message is displayed.


Transferring files was snap. In my opinion, the best way to transfer files for Android devices. Although this was the best method by far, I should note that the timestamp of transferred files was still changed. At this point, it's no longer a big issue because file name contains the date taken and this info as well as the time were embedded to file itself.

There are some drawbacks of this program:

  • There is no "select all" button. If you want to copy 100 files, you need to select all those files manually (or you could select a folder)
  • dukto needs to be running on both devices simultaneously
  • dukto must be active while transferring files; otherwise, it halts the process. This means no screensaver as well

The information in this site is the result of my researches in the Internet and of my experiences. It is solely used for my purpose and may not be suitable for others. I will NOT take any responsibility of end result after following these steps (although I will try to help if you send me your questions/problems).

That's all!