(Mac models released in mid-2011 or later, along with some older Macs that In other words, recovery mode won’t save you from every problem, and it’s no substitute for having a Of course, because the Recovery HD partition is actually part of your Mac’s internal hard drive or SSD, if that drive is having hardware problems, or partition-map problems, the recovery partition itself may be inaccessible. However, because Recovery HD is a separate partition-and one that’s invisible even to Disk Utility-even if you were to erase your Mac’s hard drive, recovery mode would still be available at startup. Unfortunately, because the Recovery HD volume is read-only, you can’t, say, copy your favorite third-party disk utility onto it to make that utility available in recovery mode.

The idea behind recovery mode is that if you ever have problems with your Mac’s startup volume, you can boot from Recovery HD and perform some basic troubleshooting procedures without the need for an OS X installation DVD (or, in the case of early MacBook Air models, the installation thumb drive) or a separate bootable hard drive. So not everyone will get this useful feature. In addition, that internal drive must initially have only a single partition or be a multi-partition drive that was partitioned by Boot Camp Assistant and not further modified afterwards.

In our testing, it appears this special partition is created only when you install Lion onto an internal drive formatted with a

Reset admin password mac os x lion