Error. This disk needs to be repaired. Start up with another disk. What is this?

[Kristina85]

Hello, I've included a print screen of a message I got once running "repair disk" in Disk Utility.
The message says I need to start up the computer from another disk.
Have never done that. What could this problem mean? My computer - thus far - seems to be doing/running fine. Is the hard drive slowly failing me?
Before proceeding, should I make a TM back-up?
I tried to verify the disk as part of the maintanence of my system. I am about to change to a SSD drive soon.
Your help will be much appreciated.
Kristina

 

[KimUsername]

Kristina85:

You have not said what computer you are using or what version of OS X you are using.
If your computer is still working you should try to make a backup of your hard drive just in case your hard drive is starting to fail.
You can also start your computer in the "OSX Recovery" mode by pressing "Command" + "R" at startup. See some information here https://support.apple.com/en-us/HT201314

One of the things you can do from Recovery mode is "Verify and repair connected drives using Disk Utility".
Once you hard drive is repaired (hopefully), you can then go about replacing the HD with an SSD.
Before doing that I would clone your existing hard drive using either "Carbon Copy Cloner" from Bombich
https://bombich.com approx. $40.00 or "Super Duper". This will make a bootable clone of your hard drive. You would install your new SSD in an external case and then clone hard drive.

Kim

 

[Fishrrman]

Disk Utility can't "repair" the same volume that it's booted from.

Try this:
1. Shut down, all the way off. Wait a few seconds.
2. Press the power on button
3. As soon as you hear the startup sound, hold down the option key and keep holding it down. The startup manager should appear after a few seconds.
4. You should see an icon for the Recovery Partition. Select it with the pointer and hit return.
5. The Mac should boot from the recovery partition
6. In the recovery partition (I don't really go there much), there should be an option to launch Disk Utility. Do so.
7. NOW try selecting your "main drive" volume, and hit the "repair disk" button.
8. Is the repair successful?
9. You can then restart from the recovery partition back to your "main volume".

Any better?

 

[Kristina85]

Fishrrman, and Kim,
Thank you for your answers. Well it turns out that I might have fixed it...I am not sure how or why. But first I simply made a TM back-up of all my data before doing anything else. Then I migrated my data to a new SSD and loaded El Capitan from it. In El Capitan I used the "disk utility" to once again try te repair my HDD. And now I booted from my HDD (which is now an external harddrive) and the message I got: The Volume Macintosh HD appears to be OK.
go figure.
so Fisherrrman, you seem to have been completely on the money here:
"Disk Utility can't "repair" the same volume that it's booted from."

thanks again!
Btw. I am surprised by it but I do like El Capitan (upragded to it yesterday after having used Snow Leopard for over 5 years)

 

[spaceballl]

Fishrrman, and Kim,
Thank you for your answers. Well it turns out that I might have fixed it...I am not sure how or why. But first I simply made a TM back-up of all my data before doing anything else. Then I migrated my data to a new SSD and loaded El Capitan from it. In El Capitan I used the "disk utility" to once again try te repair my HDD. And now I booted from my HDD (which is now an external harddrive) and the message I got: The Volume Macintosh HD appears to be OK.
go figure.
so Fisherrrman, you seem to have been completely on the money here:
"Disk Utility can't "repair" the same volume that it's booted from."

thanks again!
Btw. I am surprised by it but I do like El Capitan (upragded to it yesterday after having used Snow Leopard for over 5 years)

Just make sure you keep an active backup ready to go. It's fortunate that you were able to recover from this. It doesn't always turn out that way.