Lion Recovery Partition Question

[pathumx]

I was having a discussion with a friend who's drive recently got messed up and he ended up doing a full wipe to fix it.

I know that if you run disk utility when you are booted off your internal harddrive's main partition, it can't do as much when compared to running disk utility when you are booted from an install DVD. How does booting from the lion recovery partition compare?

 

[Macman45]

Tech support will often ask you to repair permissions via the recovery partition...Allegedly it's more through although I've not noticed any difference.

 

[pathumx]

I'm not 100% certain, but I think verify/repair permissions can usually be run fine from the active volume. But repair disk can't be run fully from the active volume, but you need to use the install dvd to fully run it sometimes. I just don't know if the recovery partition can run it fully on the main partition, which is what I'm asking.

 

[Weaselboy]

I just don't know if the recovery partition can run it fully on the main partition, which is what I'm asking.

Yes, the recovery partition can run the full disk repair just like if you booted from a DVD.

 

[robgendreau]

It's a partition on the same drive. So if your hard drive is completely hosed, then you won't even be able to boot the computer from it.

People often conflate "hard drive" with volume, since they often use one partition. And it's true that just one partition or volume can become corrupted and useless, and you can use the other to fix it. In that sense using the Recovery partition/volume to run repairs is the same as using a removable volume, like a DVD, to do the same (putting aside the issue that the most recent Lion install of Recovery might have tools that your DVD doesn't have).

But again if you entire hard drive fails, as when the platter doesn't even spin, then that Recovery partition isn't available either. And if you boot from the Recovery partition you can't, of course, format the entire drive, while you can from an external. But Recovery can completely erase the other PARTITION/volume, the one that had your system on it, and reinstall Lion.

HTH,
Rob