Opening iPhoto Library with Photos

Photos can read the iPhoto Library and open it. Your edits, caption, titles, will be migrareated, also some of your projects. See this support document: How Photos handles content and metadata from iPhoto and Aperture - Apple Support

But Photos is very different from iPhoto. It is not an update to iPhoto, it is a completely different application. See this user tip for the differences:

Photos vs iPhoto: Features and Capabilities

If you prefer to stay with iPhoto for the time being, try to install iPhoto 9.6.1.

If you originally bought iPhoto from the Mac App Store or updated it from the App Store, you may be able to install iPhoto 9.6.1 from the Purchases tab of the App Store. How to do this is explained here: Can't Update iPhoto because it is not available in the App Store

Is your iPhoto Library still on the external Seagate drive?

What exactly happens, when you drag the iPhoto Library onto the Photos icon? Do you get an error message about not enough space?

Then check the filesystem on your external drive.. To be able to open the iPhoto Library in Photos it needs to be on a drive that has the MacOS Extended (Journaled) file system. Otherwise Photos will try to create the converted copy in the Pictures folder on your Sysem drive, and there may not be enough space.

You can check the file system in the "File > Get Info" panel, when you select the external drive in the Finder.

This document explaines how to format a drive before you move a photo library there: Format external drives to Mac OS Extended before using with Aperture

If you need to change the file system, copy any files somewhere else, because reformatting a drive will erase it.

The Info panel is showing the format of the drive in the General section:

I updated to Yosemite not knowing that iPhotos would disappear and be replaced by Photo. I have transferred all photos I can find into the Pictures folder and imported to Photo, but some recent ones appear to be missing. I am trying to open my iPhoto library in Pictures (86GB) using Photo but a box comes up to say I do not have permissions and that Mac can repair. Should I try to repair? Total in Pictures folder is 115GB. I occasionally get a message to say my start up disk is full.

MarioFrez wrote:

2. When I open my iPhoto Library using my MacBookAir with iPhoto and with my MacBookPro (when it still had iPhoto before it was updated), the error not enough space would appear.

It might be possible for Photos to migrate the iPhoto Library on the NTFS drive to a Photos Library on that same drive, but only if there is at least as much free space on it as the iPhoto Library currently uses -- IOW, 360 GB or more free on that drive. This would not be the case if the drive was formatted as MacOS Extended (Journaled) because Photos saves disk space by sharing images with both librariesif & only if the drive is using that Mac format.

Note that this is not a recommendation to try that, just something to consider if nothing else works and you have room on that drive for the Photos Library.

3. My external drive (Seagate) is in the NTFS format. I wanted to transfer my iPhoto Library to another Seagate Drive with Journaled

format but not successful. An error would appear saying that there already is an iPhoto file.

How exactly are you trying to do the transfer? Does the Mac-formatted drive in fact already have an iPhoto Library on it?

4. I was able to extract the individual pictures from the iPhoto Library. But I wish I could transfer them all to Photos because it contains 2 years of work and family memories and office pictorials. Sigh.

Where did you extract the photos to? How much file space are they using? One way or another, you need enough files space somewhere for your Photos Library. Refer to my comment above about how Photos can save disk space if you can collocate its library with your iPhoto one, which could be helpful if you can get the transfer in #3 above to work.

You may also be able to use referenced files to save space if you put your Photos Library on your startup disk, but there are drawbacks to this that link mentions.

J9scott wrote:

I occasionally get a message to say my start up disk is full.

Then you need to free up at least 10-15 GB of space on it immediately. The OS requires free space for temporary files. When there is not enough space for that bad things happen, including crashes & possible data loss.

It might be possible for Photos to migrate the iPhoto Library on the NTFS drive to a Photos Library on that same drive, but only if there is at least as much free space on it as the iPhoto Library currently uses

Have you tested this? When I tried it with a test library, Photos created the migrated library on the internal drive.

I updated to Yosemite not knowing that iPhotos would disappear and be replaced by Photo

The Yosemite update does not uninstall iPhoto. It just removes the iPhoto icon from the Dock and adds the Photos icon instead. iPhoto will still be in your Applications folder. If the iPhoto icon is crossed out as incompatible update to iPhoto 9.6.1. That version is working well with MacOS X 10.10.3. See this user tip:

Get iPhoto 9.6.1 if you didn't update before OS... | Apple Support Communities

But first make space on your StartUp drive.

I did not buy iPhoto, as far as I know it came with the Mac and going to the Apps store does not bring it up as Purchased. Shall I try the repair route?

When I go to iPhoto in Applications folder it tells me I need the latest version from Apps store but I get message "The item you've requested is not currently available in the UK Store." Any ideas?

When I go to iPhoto in Applications folder it tells me I need the latest version from Apps store but I get message "The item you've requested is not currently available in the UK Store." Any ideas?

iPhoto cannot be purchased any longer from any store, because Apple stopped selling it. you can only update iPhoto be reinstalling from your Purchases tab at the AppStore. iPhoto needs to be associated with your Apple ID, either because you bought it from the AppStore or you accepted a preinstalled version to your AppleID, or you bought iLife '11, and updated iphoto using g the AppStore to version 9.4.5 or later, versions sold only from the AppStore. Get iPhoto 9.6.1 if you didn't update before OS... | Apple Support Communities

iPhoto may be hidden on your Purchases page. Try to unhide it as described here: Mac App Store: Hiding and unhiding purchases

Tried to unhide, no luck. I believe must have been pre installed. Wee have now found the missing photos which were in Cloud Drive Facebook folder. It could be that this is because these were downloaded with Canon software and confused Photos. I now have a Samsung M3 HDD and trying to format it in order to make space, told by our local Apple store (didn't buy it there) that it was OK for Mac but not able to drag and drop. How can I format?

Formatting a drive will completely erase it, so you will have to move any data somewhere else, before you do that.

Use Disk Utility to format the drive. The procedure is explained here:

Mac OS X: Mac OS Extended format (HFS Plus) volume and file limits