Thank you for buying via links and ads on this site,
which earn me advertising fees or commissions.
As an Amazon Associate I earn from qualifying purchases.

Other World Computing...
B&H Photo...
Amazon
As an Amazon Associate I earn from qualifying purchases.
877-865-7002
Today’s Deal Zone Items... Handpicked deals...
$1199 $779
SAVE $420

$249 $219
SAVE $30

$1699 $1299
SAVE $400

$1499 $1149
SAVE $350

$200 $140
SAVE $60

$89 $69
SAVE $20

$120 $35
SAVE $85

$209 $179
SAVE $30

$3498 $3498
SAVE $click

$3699 $1299
SAVE $2400

$1000 $700
SAVE $300

$3899 $1499
SAVE $2400

$748 $648
SAVE $100

$2999 $1999
SAVE $1000

$1699 $999
SAVE $700

$1698 $1398
SAVE $300

$4499 $3499
SAVE $1000

$1399 $1049
SAVE $350

$1149 $799
SAVE $350

$1399 $1049
SAVE $350

$1498 $1198
SAVE $300

$2797 $2597
SAVE $200

$280 $250
SAVE $30

$1699 $1299
SAVE $400

$8399 $7599
SAVE $800

$899 $799
SAVE $100

$1499 $999
SAVE $500

$1699 $1299
SAVE $400

Capacities up to 56TB and speeds up to 1527MB/s
OWC Envoy Pro EX SSD
Blazingly fast Thunderbolt 3 SSD!

Up to 4TB capacity, USB-C compatible.

USB-C model also available


Great for travel or for desktop!

How to boot off an external drive

Last updated 2009-08-07 - Send Feedback
Related: backup, eSATA, how-to, Mac Pro, SSD

You can start your Mac (“boot” it) using an internal or external drive. Doing so allows you to repair or erase, repair or recondition your regular boot drive.

You can clone your regular boot drive, then boot off the clone for such operations, then switch back to your regular boot drive.

Choosing your startup disk

Choose which system to boot from using
System Preferences => Startup Disk

After installing system software, the system will have set the startup volume to the new system.

At other times, you can boot using any available system on any drive by going to System Preferences => Startup Disk. After rebooting, you’ll be running whichever system you’ve chosen; you can freely reboot with either.

You can also hold down the “option” key on your keyboard right after turning on your Mac— this will provide a list of bootable systems on all attached (and powered-on) drives.

Fast and cost effective way to backup!

Other stuff

Mac Pro boot options

For Mac Pro users, an external boot drive allows use of all the internal storage bays for your data (eg for a striped RAID in a Mac Pro).

Other options also exist, such as using an internal solid state drive for a boot drive. See How to Make Your Mac Feel Lightning Fast and Installing a Solid State Drive.

Why won’t my Mac start off an external SATA (eSATA) drive?

In general, you cannot start your Mac using an eSATA (external SATA) drive. There are certain exceptions with specialized eSATA cards, and/or routing an internal SATA port outside the Mac, such as the Newer Techology Extender Cable.

Why won’t my PowerPC Mac start off an external Firewire 800 or other drive?

I regularly get emails from puzzled uses whose Power-PC Mac won’t boot off an external drive. See below for why this is so— the drive must be partitioned with Apple Partition Map.

Most vendors now ship external drives using GUID; you’ll have to re-partition the drive for PowerPC booting.

Which Camera System 📷 is Best?
Which Lenses to Choose?🌈


Avoid costly mistakes and get the ideal system for your needs: diglloyd photographic consulting.

Cloning a drive

In most circumstances, don’t waste your time re-installing a system and all your applications.

See How to Upgrade Your System/Boot Drive and How to Clone a Drive/Volume.

Partition table type

See Partitioning for more on the process of turning a drive into useful volumes for your Mac.

Select the hard drive at left, and click the Options… button.

All Intel Macs should use GUID Partition Table.

Choose Apple Partition Map to start up a PowerPC Mac. If you don’t do so, you won’t be able to boot your PowerPC Mac and you’ll have to repartition the drive.

Use GUID for Intel-based Macs, and Apple Partition Map

 

OWC Envoy Express

World’s first Thunderbolt 3 M.2 NVME SSD enclosure.

Super fast, bus-powered, 3.3 oz, DIY easy, rugged and compact!


See also OWC Express 4M2
√ No more slow and noisy hard drives!
OWC Accelsior 4M2 PCIe SSD
6000 MB/sec!
Mac or PC.


Ideal for Lightroom, Photoshop, video.
Capacity up to 16TB!
OWC Thunderblade Thunderbolt 3 SSD

Blazing fast, up to 16TB.

YEE HAH!



√ No more slow and noisy hard drives!

MacPerformanceGuide.com
View all handpicked deals...

LG UM7370PUA 70" Class HDR 4K UHD Smart LED TV
$1199 $779
SAVE $420

diglloyd.com | Terms of Use | PRIVACY POLICY
Contact | About Lloyd Chambers | Consulting | Photo Tours
Mailing Lists | RSS Feeds | Twitter
Copyright © 2020 diglloyd Inc, all rights reserved.
Display info: __RETINA_INFO_STATUS__