Showing posts with label Mac. Show all posts
Showing posts with label Mac. Show all posts

Wednesday, 28 January 2015

How to Free Up Space on an iPhone or iPad


ipad-air
iPads and iPhones don’t have file systems you can see, but there are still apps and files eating up space. You can see exactly what’s consuming that limited space and free it up.
Each bit of data on your device is associated with an app. For example, downloaded Kindle eBooks are tied to the Kindle app. Music files are part of the Music app, videos are part of the Videos app, and photos are part of the Photos app.

View Per-App Storage Usage


The number displayed to the right of each app includes the app’s application files, cached documents and data, and media files. Tap the app to view exactly what part of the app is using up the space.
Your device’s Usage screen shows an overview of the storage space used on your device and exactly how much each app is using. Open the Settings app, select the General category, and tap Usage to view it.
ios-7-view-storage-usage-in-settings

Delete Apps

Free up space by removing apps. Games are particularly large, so your installed games will probably appear near the top of your Usage list. Tap an app in the list and tap Delete App to remove it from your device.
You can always reinstall the app later. Just visit the app store, search for the app, and download it again. If the app uses iCloud syncing or its own user account system, your saved settings and data may be accessible even when you reinstall the app later.
delete-large-apps-and-games-to-free-up-space-on-ipad-or-iphone

Clear an App’s Documents & Data

Some apps have quite a bit of space used by their “Documents & Data.” In the screenshot below, the Pocket app itself is using up 37.4 MB, while its documents and data are using up a comparatively whopping 191 MB.
what-is-documents-and-data-in-storage-usage
An app’s Documents & Data include any documents and other files the app has downloaded or created. For example, the Pocket app’s Documents & Data include offline copies of articles in our Pocket queue. The Amazon Kindle app’s Documents & Data include any eBooks you’ve downloaded for use offline. Google Chrome’s Documents & Data include your settings and Chrome’s browser cache.
You can’t actually clear an app’s Documents & Data from this screen. Instead, you’ll need to either delete the app and reinstall it or clear the an app’s temporary data from within the app. For example, you can open the Settings screen in Pocket and tap Clear Downloaded Files to remove offline copies of downloaded articles. This will reduce the Pocket app’s Documents & Data usage. Not every app has this sort of option, so you may have to delete and reinstall an app if it’s using too much space for its temporary data.
clear-pocket-app's-documents-&-data-on-iphone-or-ipad

Delete Music, Videos, Photos, and Other Media Files

Videos, music, photos, podcasts, and other media files are stored as part of the associated app. The Music and Videos apps in the storage list show how much space music and video files are taking up on your device.
Tap the Videos app to see a list of videos taking up space. Swipe a video to the left and tap Delete to remove it from your device, freeing up space. The Podcasts app allows you to delete downloaded episodes in a similar way.
delete-videos-to-free-up-space-on-ios-7
The Music app just shows a total amount of space used by all music on your device. Swipe All Music to the left and tap Delete to remove all music from your device.
If you’d rather remove individual songs, open the Music app itself, swipe a song to the left, and tap Delete.
delete song in music app to free up space on ipad or phone
Photos work similarly. The Photos & Camera app in the Usage list displays how much storage is used by photos on your device. To actually remove these photos, you’ll need to open the Photos app, select the photos you want to delete, and tap the Delete button.
delete-photos-from-ipad-or-iphone

Erase Browsing Data

The Usage screen displays different types of browsing data when you tap the Safari app. Tap Website Data to and tap Remove All Website Data to remove cache and cookies. Swipe to the left on Offline Reading List or History and tap Delete to delete these other types of data.
clear-safari-browsing-data-on-ios-7
If you use Google Chrome, you can clear Chrome’s cache by opening the Chrome app, accessing the Settings screen, tapping Privacy, and clearing your browsing data. Chrome’s browsing data appears as Chrome’s “Documents & Data” on the Settings screen. Other third-party browsers work similarly.
clear-browser-data-in-chrome-on-ipad

If you can’t figure out how to clear an app’s documents and data, just uninstall the app and reinstall it. You may need to set up the app again afterward if it doesn’t sync its settings online.
For Apple’s own preinstalled apps, you can open the the app itself and remove content to free up space. For example, iMessage may be eating up quite a bit of space. You can open the iMessage app, locate message threads containing file or photo attachments, swipe to the left on them, and tap Delete to delete them from your device.

Saturday, 24 January 2015

How to Quickly Batch Rename Files on Windows, Mac OS X, or Linux


Windows, Mac OS X, and most Linux desktops have built-in tools for quickly renaming multiple files. Use a batch-rename tool rather than fixing them one by one.
More powerful batch-renaming features may require a third-party tool or the command line. Batch-renaming features are often integrated into third-party file managers, too.

Windows


We’ve already covered the many ways to batch-rename files on Windows. For basic batch-renaming, begin by selecting several files in Windows Explorer or File Explorer. Press Ctrl+A to select a folder full of files, use the mouse cursor to select a group, or hold Ctrl as you click to select and de-select files.

More advanced operations will need Command Prompt commands, PowerShell cmdlets, or third-party bulk-renaming tools. (Be extremely careful when downloading and running such third-party software, as there’s a good chance you could end up with adware or malware.)When you’re ready, right-click a file in the list and select Rename — or just press F2. Type a new “base name” for the files, such as My Vacation, and press Enter. The files will be renamed as My Vacation (1), My Vacation (2), and so on. This will give all those files a much more logical name, grouping them together.

Mac OS X

Mac OS X’s Finder gained its own batch-rename function in version 10.10 Yosemite. These built-in batch renaming features are much more powerful than the built-in Windows ones.
To get started, select the files you want to rename in the Finder, Ctrl-click or right-click them, and select Rename items. You’ll see a Rename dialog where you can choose between three options. Here’s what they do:
  • Replace Text: This option lets you perform a search and replace in the selected files’ names. Enter text you want to find and the text you want to replace it with. For example, you could replace the words “My Vacation” with “Paris Trip.” Or you could search for a bit of text and replace it with nothing at all, snipping that bit of text out of every file name.
  • Add Text: This option allows you to add some text to each file name. You can add the text either before or after the name.
  • Format: This is the most complicated option. You can “format” file names, using a base name and a number. This works similar to the equivalent renaming feature on Windows. You could also use the file’s associated date instead of a number. The number or date can appear before or after the base name.
This may sound a bit complicated, but it’s not too bad. You’ll see a preview of the resulting file name appear below the Rename dialog, so you can see exactly how the files will be named. Feel free to experiment!

Linux


If you’re using a KDE desktop, the standard Dolphin file manager does have this integrated. It works like the batch rename feature on WIndows. Select multiple files, right-click them, and select Rename or press F2. Enter a base name for the files, including the # symbol somewhere in it. The # symbol will be replaced by a sequential number for each file name. For example, if you enter Photo # From My Vacation.jpg, you’ll get files named “Photo 1 From My Vacation.jpg,” “Photo 2 From My Vacation.jpg,” and so on.Some Linux desktop environments come with an integrated batch-renaming tool, and some don’t. The Nautilus file manager used by Ubuntu’s Unity desktop and GNOME doesn’t have this feature built-in.
The Xfce desktop and its Thunar file manager has an easy-to-use, powerful bulk rename tool built into it. To access it, select some files in Thunar, right-click them, and click Rename. This tool can do everything from renaming files based on their audio tags, inserting a date and time, numbering files, performing a search and replace, making text uppercase or lowercase, inserting or deleting characters at a specific position in the file name, and so on.
Thunar’s interface is powerful, but it’s also fairly simple to understand. The preview of how each file’s name will look afterwards helps you experiment safely, so you can see exactly what its functions will do.
On other desktop environments, you can head to your Linux distribution’s software management program and install a bulk-rename tool. We do like Thunar’s Bulk Rename tool, even on GNOME and Unity desktops. Install Thunar on another desktop environment to get a “Bulk Rename” tool you can launch directly from your Linux desktop’s applications menu. Drag-and-drop files from your desktop’s file manager into the Bulk Rename window to start renaming them.
You can even integrate Thunar’s Bulk Rename tool into the Nautilus file manager using the Nautilus Actions tool.
As on other operaitng systems, you can also batch-rename files from the terminal. The Linux terminal is so powerful that you can batch-rename files in all sorts of ways.

Batch-renaming isn’t something every computer user needs to do regularly, but it is often useful. That batch of oddly named image files from your digital camera’s DCIM folder are prime targets for a good batch-renaming when you import them to your computer.

Thursday, 22 January 2015

How To Clear (Flush) DNS Cache In OS X Yosemite


So, you want to clear your OS X’s DNS cache but don’t know how and even dscacheutilisn’t getting the job done. That is possibly caused by you being on a different version of Mac’s operating system, most probably OS X Yosemite 10.10.
To clear DNS caches completely on OS X Yosemite (version 10.10.x), you will need to clear both MDNS (Multicast DNS) and UDNS (Unicast DNS) caches via Terminal. Here’s how you can get this done.

Method 1: Clear MDNS & UDNS Caches Separately

Enter the following commands separately in your terminal.
The first will clear the MDNS cache and the second will clear the UDNS cache. You will require the admin password to perfom this task.
  1. sudo discoveryutil mdnsflushcache  
  1. sudo discoveryutil udnsflushcaches  
That’s all! Click here to read more about flushing DNS cache in OS X Yosemite.

Method 2: Clear MDNS & UDNS Caches Together

Alternatively, you can use the following command. Basically it’s the same, it combines both of the above into one.
  1. sudo discoveryutil mdnsflushcache;sudo discoveryutil udnsflushcaches;say flushed  

Clearing DNS Cache In Other Mac Versions

If you are not on OS X Yosemite yet, here is a recap of how to clear or flush dns cache in older versions of Mac.
OS X Mavericks (10.9)
  1. dscacheutil -flushcache; sudo killall -HUP mDNSResponder  
OS X Mountain Lion (10.8)
  1. sudo killall -HUP mDNSResponder  
OS X Lion (10.7)
  1. sudo killall -HUP mDNSResponder  
OS X Snow Leopard (10.6)
  1. sudo dscacheutil -flushcache  
OS X Leopard (10.5)
  1. sudo dscacheutil -flushcache  
OS X Tiger (10.4)
  1. lookupd -flushcache  

Monday, 29 December 2014

How to Use a Scanner on Your Mac OS X Computer


Scanning a document in Mac OS X is extremely simple, but for those who might not be familiar, or are coming from Windows, it’s useful to take a quick tour through how it works.

Scanning in OS X is Easy
It’s worth noting that a good percentage of the time you can just use your smartphone’s camera and scan it to PDF easily. For most common scanning tasks, that option will work really well, and it’s an especially great option for scanning a picture of a receipt to save into your digital archive.
You can open the Printers & Scanners app through System Preferences, but it’s easier to use CMD + SPACE to pull up Spotlight and type in “Scanner” to bring it up.
You could alternatively search for the name of your printer.
Once you’ve opened the preferences panel, you’ll see your printer, and you’ll want to click on Scan, and then Open Scanner.
If you have more than one printer or scanner you can select between them.
At this point you’ll see the Scanner window, and you can click the Scan button, but we’d recommend using the Show Details option to get into the settings for the scanner. If you have a sheet feeder, you could select that checkbox, and change the drop-down from Pictures to something else before scanning, but it’s easier to just get into the details first.
Once you’ve arrived at the Details screen, your scanner will usually warm up and take a preview scan before you select the options for the actual scan, although this will load from the flatbed.
You can order Alaskan king crab legs online, and they are delicious.
Most of the options make sense and are straight-forward, but we’ll list out the important ones just in case.
  • Scan Mode – If your scanner has a sheet feeder, you can use this to select that instead of the flatbed.
  • Kind – If you only want black and white you can change to that mode for documents, although the default Color option is probably just fine.
  • Resolution – You can almost always leave this at default for documents, unless you are trying to scan photographs, in which case you would want to use a higher resolution. 300 dpi will be just fine for a document.
  • Scan To – You can choose a different folder than the default, which is your Pictures folder for some reason, even though the default format is PDF. It would make more sense to have Documents as your default folder, but whatever.
  • Name – This is what the file is actually going to be saved as. Change this to something descriptive.
  • Format – The default is PDF, but you can change it to an image format instead if you are scanning pictures. You can also use the “Combine into single document” checkbox to take everything off the sheet feeder and put it into a single document.
Once you’ve selected your options, which mostly consists of selecting between sheet feeder or flatbed, picking the folder, and changing the name of the document, you can simply click Scan to start the scanning process.

Saturday, 27 December 2014

How to Record Your Windows, Mac, Linux, Android, or iOS Screen


young man with digital video camera
Screenshots are great, but sometimes you need to create a video recording to really get your point across. You can record your computer’s desktop, your smartphone’s screen, or your tablet’s display.
This process gives you a video file, which you can do whatever you like with. Upload it to YouTube or email it to a friend. Put together a video tutorial or just capture a problem you’re having so you an demonstrate it later.

Windows


Windows doesn’t include a built-in tool for creating desktop recordings. There are many tools for doing this, but make sure you avoid the junkware bundled into their installers if you go hunting for them. You can actually use VLC to record your desktop, and that’s a convenient option. There’s a good chance you already have VLC installed, and it’s a Swiss army knife that will allow you to quickly record your desktop without installing anything else.

For more advanced screencasts, we recommend OBS (Open Broadcaster Software). It’s very powerful, free, open-source tool that allows you to do more. Insert watermarks, embed a video of your webcam while capturing your desktop, choose specific desktop windows, and so on. OBS is widely used for video-game-streaming on Twitch.tv because it’s so powerful, but it works just as well for creating a professional-looking video of your desktop.

Mac OS X


To record your Mac’s screen, open the QuickTime application — press Command + Space to open Spotlight search, type QuickTime, and press Enter to do so. Click the File menu on the menu bar, select New Screen Recording. You can then click the little menu to the right of the Record button and choose whether you want to capture audio from your microphone in the video, too. This will allow you to narrate along with your actions. Click the Record button to start when you’re ready.Mac OS X offers a convenient, built-in screen-recording tool. It’s one of the many useful functions hidden in QuickTime, which is more than just the simple media player it looks like on the surface.
QuickTime will minimize itself to a small icon on the right side of your menu bar and start recording. Click Stop when you’re done, and you’ll be able to preview and save your video. QuickTime can also edit the video, trimming out any unnecessary bits.
For something more powerful, you may want to try Open Broadcaster Siftware (OBS). It’s not just for Windows — it works on Mac, too.

Linux

There are quite a few open-source screen-recording applications for Linux, and you’ll probably find many of them if you pull up your Linux distribution’s package manager and do a quick search. There’s even a way to do this with ffmpeg and other commands from the terminal, if you’re into that sort of thing.
One of the most popular and longest-standing open-source tools for this is recordMyDesktop, which you can install from the Ubuntu Software Center or your Linux distribution’s package management interface of choice.
Launch recordMyDesktop and use its options to choose video and audio quality levels. This tool can record your entire desktop or just a small portion of it. recordMyDesktop works well, provides a simple interface, and offers the most important desktop-recording options.
If you want something more powerful, try Open Broadcaster Software (OBS). It’s available for Linux as well as Windows and Mac OS X.

Android


Connect your Android device to a Windows, Mac OS X, or Linux PC with a USB cable and use the “adb shell screenrecord” command to start recording its display. If you have a rooted device, you can also initiate a screen recording with an app on your device — but that app needs root permissions.Android allows you to capture a video of your device’s display and save it as an mp4 file. This feature was added in Android 4.4, and it still works on Android 5. To do this, you’ll need to connect your Android device to a PC and use the adb command. Apps on your phone can’t start recording your display on their own — this prevents apps from initiating a recording to capture you entering sensitive data.

iOS


If you have a Mac and an iPhone or iPad, you can connect your iPhone or iPad to it and use the QuickTime application to capture its screen. Just select “New Movie Recording” instead of New Screen Recording, click the menu button, and select the connected iOS device instead of your Mac’s built-in webcam.Apple now offers a convenient, official way to record an iOS device’s screen. This requires a Mac running OS X Yosemite and an iPhone, iPad, or iPod Touch running iOS 8 or newer. Unfortunately, this feature is only available for Mac users. It’s intended for developers to capture their apps in action, and iOS developers will need to have Macs anyway.

You can live-stream your desktop instead of recording it, too. On a desktop PC or laptop, OBS works very well for live-streaming. You can even live-stream your desktop straight from VLC!

The Best Alternative File Managers for Windows, Mac, and Linux


One-Click Management
Most people use their operating system’s included file manager, but many geeks prefer third-party file managers. After all, Windows Explorer doesn’t offer tabs, a dual-pane interface, batch file-renaming tools, and more advanced features.
If you’re happy with your default file manager, that’s fine. These alternatives are really only useful if you’re craving a particular feature not found in your current file manager.

Windows


For as long as Windows Explorer has existed, Windows geeks have yearned for more features. There are many, many Windows Explorer alternatives out there. When installing them, be sure ot watch out for the junkware packed into their installers. The Windows software ecosystem is sick, and  — in general — we hate recommending Windows software downloads for just this reason.

FreeCommander is a good option if you’re looking for tabs, a dual-pane interface, and all the other powerful features a Windows Explorer replacement can offer. Unlike many of the other available applications, it’s available entirely for free — although it isn’t open-source. You’re free to use it all you like, even for commercial purposes. No features are restricted to some sort of professional edition you have to pay for. Multi Commander is similar and also free.
Explorer++ is free and open-source, so it also won’t try to nag you for money or install junk onto your system. It includes tabs, a customizable user interface, file-filtering features, and can even run as a portable app without any installation. It offers a cleaner interview than Free Commander, but without the dual-pane view and some other powerful features. If all you want is a tabbed interface and a few other things, this is a great option
Other file manager replacements include Xplorer2, XYplorer, Directory Opus, and Total Commander. All of these programs offer paid editions they want you to purchase. There are free versions available for most of them — Xplorer2 Lite, XYplorer Free, and Directory Opus Light. They often lack many of the more powerful features found in the paid versions, but they’ll provide you with many of the features found in the paid versions.

Mac OS X


The Finder app included with Mac OS X does the basics, but it can certainly leave you wanting. As usual on Mac OS X, many of the alternative file-manager options available to you are generally paid software. You’ll have to shell out a few bucks to use them. On the bright side, this means that they see more development than many alternative Windows file managers, and their business model is selling software instead of trying to load your computer with crapware in their installers.

Cocoatech’s Path Finder is probably the most popular Finder replacement for Mac OS X, and we covered it as one of the best options if you want to merge folders on your Mac. It also includes a dual-pane interface and other powerful features. Developers in particular can get a lot of use out of its intergrated Git and Subeersion support, as well as easy access to a terminal.
Path Finder costs $40, but you can use the free 30-day trial to determine if you actually need all those fancy features.
If you want some of these advanced features — like a dual-pane interface — but don’t want to spend money on this type of program, try XtraFinder. It’a free application that adds features to the Finder, including a dual-pane interface, a copy queue, global hotkeys, and many new menu options. It doesn’t include nearly as many advanced features as Path Finder does, but most people don’t need all those bonus features. This could hit a good sweet spot for many people.

Linux


For example, GNOME and Ubuntu’s Unity desktop include the Nautilus file manager. KDE includes the Dolphin file manager, Xfce includes the Thunar file manager, and LXDE includes PCManFM. Each file manager has its own unique features — for example, Xfce’s Thunar file manager includes an integrated Bulk Rename tool for quickly batch-renaming files.It’s hard to talk about alternative file managers for Linux, as every desktop environment tends to include its own unique file manager. These file managers also tend to see more development and often include advanced features you’d only find in alternative file managers on other operating systems. But, thanks to the modularity of the Linux desktop, you could actually run a different desktop environment’s file manager on your current desktop.
Every file manager tends to match its desktop environment in philosophy. For example, GNOME’s Nautilus file manager is shedding features with every release, chasing GNOME’s goal of simplicity and minimalism. Dolphin is more feature-heavy and uses the Qt toolkit instead of GNOME and Xfce’s GTK toolkit. Thunar, like Xfce itself, is a more minimal, barebones file manager that still has everything you need and gets the job done. Like LXDE itself, the PCManFM file manager offers a fairly minimal, lightweight interface.
Perform a search for “file manager” or something similar in your Linux distribution’s package management interface and you’ll find a lot of options.

So, do we think everyone needs to hunt down an alternative file manager? Not at all. We’ve usually been happy with the integrated file managers, which are there and get the job done if you don’t need anything special.
But lots of geeks do love their alternative file managers, and for good reason. They offer powerful features that can save you a lot of time if you need them.

Friday, 26 December 2014

Drive Icons Missing From Your Mac’s Desktop?

Desktop with Drive Icons - Screen shot courtesy of Coyote Moon, Inc.
Screen shot courtesy of Coyote Moon, Inc.
Question: Drive Icons Missing From Your Mac’s Desktop?
My Mac doesn’t display any drive icons on the desktop. I know it’s supposed to, because I’ve seen hard drive icons displayed on my friend’s Mac or at the Apple Store, where I bought my Mac.
How do I get my Mac to display the hard drive icons?
Answer:
It's the Finder's job to display the desktop and all of its icons, including those for hard drives. The problem is that a default install of OS X renders the desktop without the drive icons.
Luckily, this is easy to correct. In fact, you can specify which desktop icons you would like to have visible simply by setting the preferences in the Finder.

Setting Which Desktop Icons Display

  1. Click on the desktop or open a Finder window, to ensure the Finder is currently the front most application.

  2. From the menu bar, select Finder, Preferences.

  3. In the Finder Preferences window that opens, click the General tab.

  4. Place a check mark next to the items you wish to display on the desktop. The options include Hard disks, External disks, CDs, DVDs, iPods, and Connected Servers.

  5. Close the Finder Preferences window.
The selected items will now display on the Desktop.

Saturday, 6 December 2014

Amazing Tips to Speed up your Slow Mac



Amazing Tips to Speed up your Slow Mac
Over the years, the Macs have built the formidable reputation that they never slow down and run forever, never crash. However, the fact is that Macs also slow down and they also crash. However, they crash differently. Virus attacks also happen to Mac.

Free solutions are not better solution for this problem. Upgrading system hardware and adding RAM are always better options. There can be some tips in in order to speed up Mac. These are discussed below:

Deletion of all Unused Programs

Uninstallation of the app on the Mac and the dragging off the files from the application folder are not similar to the same extent. The support files of the application remain on the system and we need the services of the Utility called AppCleaner, which helps to locate these files and then eventually remove them.

Removal of the Startup Items

The programmers are always prioritizing the programs over any of the apps. Therefore, a brilliant idea will be to add the piece of code to the startup items. If there are enough of these programs, the system will be slowed down as a result. We need to remove these with the following steps:

System preferences -> Accounts- > Login items

The app is highlighted and the minus button is clicked, at the bottom of the list. The programs can still be used, but when it is needed.

Getting rid of the unwanted


There are lots of extra built-ins in Mac to speed up Mac. These are in unspoken languages and compatibility files for the old Mac architecture. Monolingual will ensure that all these additional languages are removed and the support for the older hardware. If the user is running the Intel Mac and are not using any older programs, then the support for PowerPC and the ARM can be withdrawn. The OS X install disk is required to get back, any of the required language or architecture, at a later time.

Shutting down of unwanted Apps

Shutting down the unwanted apps will ensure that they consume less memory and less CPU space. Right-click can be used on the programs in the Dock and then Quit chosen. Another option is pressing the Command-Tab for the App Switcher and then Command-Q is used for quitting the unused programs.

The Activity Monitor in the Utilities folder can show all the running processes on the Mac System.

On pressing the CPU button, the “%CPU” column can give a list of all programs by their CPU usage. We can also see the network, memory and the disk, as used by the different processes.

Deep Cleaning

Disk Utility always makes the life of the Mac user easier. Onyx is more robust and detailed. The miscellaneous junk that is accumulated on the Mac can be removed with the help of this Utility. The routine maintenance activity can be done with the help of this Utility. Other activities like verification of the startup disks for correcting the file system errors and finding hidden tweaks are also done by this Utility.

The Widgets

The cool widgets are because of the dashboard in Apple. These small and little apps for the weather forecasting and the stock prices are not only easy but also convenient. More are the number of widgets, running in the background; more resources are given by the OS X. We must take care, that unnecessary widgets are not kept open, particularly when they require upgrade on a constant basis.

Preference Panes

The custom items are being displayed in the preference panes and this consumes CPU resources. The item should be removed, if not needed

Tuesday, 25 November 2014

Moving Time Machine to a New Hard Drive

iMac with Time Machine logo - Apple Inc.
Apple Inc.
It's a law of the universe. Sooner or later, Time Machine backups expand to fill all available space on a hard drive. It's actually a capability that we're glad Time Machine possesses. By using all available space, Time Machine can keep backups of our work going back as far as…well, as far as there's available space.
Eventually, though, you may decide you need more room for your Time Machine backups, and want to move them to a larger hard drive. You may need more room for two primary reasons. First, the amount of data you store on your Mac has grown over time, as you've added more applications and created and saved more documents. At some point, you may outgrow the amount of space available on your original Time Machine hard drive.
The other common reason for needing more room is a desire to store more data history. The more data history you can store, the farther back in time you can retrieve a file. Time Machine will obligingly save multiple generations of documents or other data, as long as you have enough room to accommodate them. But once the hard drive fills up, Time Machine will purge older backups to ensure you have room for the most current data.

Moving Time Machine to a New Hard Drive

Starting with Snow Leopard (OS X 10.6.x), Apple simplified what's required to successfully transfer a Time Machine backup. If you follow the steps below, you can move your current Time Machine backup to a new disk. Time Machine will then have enough room to save a larger number of backups, until it eventually fills up the available space on the new drive.

Preparing the New Hard Drive to Be Used for Time Machine

  1. Make sure your new hard drive is connected to your Mac, either internally or externally.

  2. Start up your Mac.

  3. Launch Disk Utility, located at /applications/utilities/.

  4. Select the new hard drive from the list of disks and volumes in the left side of the Disk Utility window. Be sure to select the disk, not the volume. The disk will usually include its size and possibly its manufacturer as part of its name. The volume will usually have a simpler name; the volume is also what shows up on your Mac's desktop.

  5. Time Machine drives need to be formatted with the GUID Partition Table. You can verify a drive's format type by checking the Partition Map Scheme entry at the bottom of the Disk Utility window. It should say GUID Partition Table. If it doesn't, you will need to the format the new drive.
    WARNING: Formatting the hard drive will erase any data on the drive.
    To format the new hard drive, follow the instructions in the guide below, and then return to this guide:
    Format Your Hard Drive Using Disk Utility
    If you want the new hard drive to have multiple partitions, follow the instructions in the guide below, and then return to this guide:
    Partition Your Hard Drive With Disk Utility

  6. Once you finish formatting or partitioning the new hard drive, it will mount on your Mac's desktop.

  7. Right-click the new hard drive icon on the desktop, and select Get Info from the pop-up menu.

  8. Make sure that 'Ignore ownership on this volume' isn't checked. You'll find this check box at the bottom of the Get Info window.

  9. To change the 'Ignore ownership on this volume' you will first have to click the padlock icon located in the bottom right corner of the Get Info window.

  10. When prompted, supply an administrators username and password. You can now make the changes.

Transferring Your Time Machine Backup to a New Hard Drive

  1. Launch System Preferences by clicking the System Preferences icon in the Dock, or selecting System Preferences from the Apple menu.

  2. Select the Time Machine preference pane.

  3. Slide the Time Machine switch to Off.

  4. Return to the Finder and browse to the location of your current Time Machine backup.

  5. Click and drag the Backups.backupdb folder to the new hard drive.

  6. If asked, supply an administrator name and password.

  7. The copying process will start. This can take a while, depending on the size of your current Time Machine backup.

Selecting the New Hard Drive for Time Machine's Use

  1. Once the copying is complete, return to the Time Machine preference pane and click the Select Disk button.

  2. Select the new hard disk from the list and click the Use for Backup button.

  3. Time Machine will turn back on.
That's all there is to it. You're ready to continue using Time Machine on your new, spacious hard drive, and you didn't lose any of the Time Machine data from the old drive.