Showing posts with label unix. Show all posts
Showing posts with label unix. Show all posts

Friday, March 13, 2015

iPhone: Repair black/white and corrupt photo thumbnails in camera roll


The iPhone camera roll photo thumbnail database can become broken and corrupt. This results in either black/white thumbnails and fully functional photos or functional thumbnails but black/white photos. Typically this happens when the users backup their iPhone camera roll photos to a computer without using iTunes, which is not even available for the popular Ubuntu/Debian/Fedora Linux distributions. The fix, which is described here, is to regenerate or repair the photo thumbnail database.

ios, fix, tutorial, guide, black, white, missing photo, missing thumbnail, photo error
Everyone should ensure that they back up the photos on their phones from time to time. Whether this is done to the cloud or to their home computer, a working routine is extremely important to prevent irreparable damage if one loses the phone. For iPhone users, backup to iCloud of the camera roll photos can be easily set up, although in the long run this is not a sustainable solution due to the space limitations on the iPhone itself as well as on iCloud. Simply put, keeping all photos ever taken on your iPhone is not a sustainable solution. Therefore, users should occasionally backup their photos to a computer to free up the storage space of their iPhone as well as iCloud account.

The process of backing up the iPhone photos from the camera roll can be performed through iTunes, although many users find it slow, bloated and sluggish. For Linux users, such as the popular Ubuntu and Debian users, iTunes is not even available. Thus, the use of a file manager to transfer the data in the DCIM folders is preferred by many for its transparency, and effectiveness. Unfortunately, it has been shown that backing up photos in this way may corrupt the photo thumbnail database, causing it to lose its sync with the camera roll. This results in either non-existent (black/white) photos, or black/white thumbnails when the users attempts to access their iPhone photos. This tutorial shows how to fix and repair the camera roll photo thumbnail database.




Friday, March 6, 2015

How to ping BackupPC hosts behind a NAT router or firewall

BackupPC is a very capable open-source enterprise-grade backup system that is readily available for most Linux distributions, e.g., Ubuntu, Debian and Fedora. However, since most computers today are behind a NAT router or firewall, this completely breaks the ping command that a remote BackupPC server uses to check if a host client is alive or reachable. The most common solutions which allow BackupPC to ping host clients that are behind a NAT router or firewall are discussed here.

ubuntu, debian, linux, pincmd, pingpath, tutorial, hping3, aliveBackupPC, being open source and free, is great in many aspects and thus has also become the backup system of choice in many enterprise environments as well as home networks. Although it usually works out-of-the box in most popular Linux distributions, such as Ubuntu, Debian and Fedora, some quirks do exist. For example, the broken GUI interface caused by Apache. Another example, which is discussed here, is the ping system that BackupPC uses to check if a host computer client is alive. In addition, it will be argued why some common solutions provided on the internet are better than others based on experience and logic.

The scenario that is particularly considered is the case of a remote BackupPC server attempting to backup multiple computers that sit behind a NAT router with firewall, as illustrated in the picture above.

Tuesday, February 17, 2015

Fix for iPhone not charging through USB on Ubuntu Linux

Connecting an iPhone/iPad/iPod to Ubuntu or a modern Linux system is usually a plug-and-play experience. However, with new iOS versions, sometimes the device simply fails to charge through USB even if it is recognized by the system. While rebooting Ubuntu solves the problem, it is actually possible to resolve the problem without a reboot.

battery, linux, debian, fix, tutorial, charge, USB, iPhone, iPad, iPod
The Ubuntu Linux distribution is certainly great in many aspects, although when it comes to supporting the newest iOS versions on Apple devices, the support is usually lagging behind and also buggy and lacking. Many users of the newer iOS versions have run into cases where they have plugged in their iPhone to their Ubuntu system with everything working smoothly, and all of a sudden (while the iPhone is plugged in), the iPhone simply cease to charge or become unreachable on Ubuntu. Rebooting the computer does bring the iPhone back to life, however, the problem is more easily solved if we understand it better. 

Thursday, February 12, 2015

How to put Matlab icon/shortcut on Ubuntu Unity launcher bar

The Ubuntu Linux is one of the most popular distributions to run Matlab on *nix systems. However, the Unity launcher used by Ubuntu does not support Matlab by default and putting a shortcut to Matlab is a confusing and non-trivial task. This tutorial demonstrates an easy and straight-forward way to integrate Matlab with Unity in Ubuntu.

unity launcher, linux, ubuntu, matlab, shortcut
The powerful scientific computing tool, Matlab (Matrix Laboratory) from Mathworks is certainly a widely used tool in the scientific world. While Mathworks does provide good Windows, Linux, *nix, Mac OS X support for Matlab out-of-the-box, one overlooked aspect is the integration of Matlab to the Unity launcher used in Ubuntu.