This option on boot trick works for quite literally any boot volume, whether it’s an external USB drive of any sort, a Thunderbolt hard drive, boot DVD, CD, the Recovery partition, even in dual-boot environments with other versions of OS X, or a Linux or a Windows partition with Boot Camp, if it’s bootable and connected to the Mac it will. External universal serial bus (USB) bootable hard drives are the ultimate computer user's self-sufficiency tool. Players for mac. Wise computer users ensure they have a USB bootable hard drive on hand in case they encounter such technical issues as a computer refusing to boot.

Overview— Part of a prudent backup plan is having a Boot Clone. This along with an independent (TM) back-up will help save your bacon in most any type of data lose, system corruption, catastrophic failure or reinstalling an Operating System. The key concept in any back-up plan is redundancy, (i.e.

More than one single back-up device and more than one methodology) the boot clone can serve as a vital part of this one two punch of data protection. All Hard Drives ( read HD, SSD, SSHD [ solid-state hybrid drives] or Fusion drives ) will fail, and can do so at the most inopportune time. One of the main benefits of the Boot Clone is you can boot your machine directly from this external HD, and pick up where you left off without experiencing any down time in your productivity should your internal HD fail. This will allow you to come to terms with your current situation and make a contingency plan for repair, all the while having a fully functional OS X to continue operating.

Time Machine does not have this capacity to boot as a usable OS X. However, according to Apples support article ( you can select your TM backup drive ( ”EFI Boot”) from the Startup Manager and it will boot into Recovery Mode—from which you can use the Disk Utility to format a replacement drive—and subsequently use TM to restore its content.

The main advantage of TM is that it creates recursive backups—enabling you to restore a specific file or the entire drive— from a certain point in time. 'Your Mac notebook computer might not always be near your Time Machine backup drive, so Time Machine also saves some of its backups to your startup drive. These local snapshots are automatically enabled when you turn on Time Machine' If your Time Machine (Time Capsule) fails, becomes corrupt or does not inherit—you will be thankful you had an alternative backup strategy. Also when upgrading a new internal HD you can format this new drive externally, and create a boot clone to this new drive before removing and replacing your internal HD. This is a fast and easy process, and a simple enough procedure if you have the correct software, two of the most popular: Carbon Copy Cloner Super Duper You will need an external enclosure to hold the new drive. There are many options, a popular choice is OWC ( now MacSales.com) Here you can buy HD/SSD replacements, enclosures or kits (with tools included ) First all new drives must be formatted using Disk Utility.app—this is found in your Applications/Utilities folder, or via Recovery The important part of formatting your drive for OS X is a GUID Partition Table and the file system Extended Journaled. You can read more: Hopefully this short overview demystifies the concept of BootClones, the advantage of a redundant backup plan, and the resources to help you move forward.

Whatever you do, back up early and often. Apple Footer This site contains user submitted content, comments and opinions and is for informational purposes only. Apple may provide or recommend responses as a possible solution based on the information provided; every potential issue may involve several factors not detailed in the conversations captured in an electronic forum and Apple can therefore provide no guarantee as to the efficacy of any proposed solutions on the community forums. Apple disclaims any and all liability for the acts, omissions and conduct of any third parties in connection with or related to your use of the site. All postings and use of the content on this site are subject to the.

This question already has an answer here: • 5 answers I have an iMac 27 inch, and one summer the room temperature was up to 40C, and I came home that day, and the hard drive was really slow. I then rebooted the machine and it took something like 8 minutes to boot up since then. So I suspect the hard drive is not working so well any more. Can I now use one of those Samsung T1 SSD USB drive, or a Seagate 2TB external USB drive, or a WD Thunderbolt My Book, and boot up the iMac using this drive from now on? The thing is, how do I make such a bootable drive, when the original iMac isn't working so well?