Currently Being ModeratedNov 15, 2013 6:02 AM (in response to Francisco fp)
Not having an up-to-date back up is like driving without a seatbelt. You may well be fine but if something goes wrong you'll be worse off than if you were wearing one.
Upgrading anything without a back up is the same, except now you're driving blindfolded and drunk, so something is much more likely to go wrong. And if it does you'll be much much worse off than if you had one.
Next: Is that a network connection to that Disk? If so, then it's not a appropriate location for an iPhoto Library.
iPhoto needs to have the Library sitting on disk formatted Mac OS Extended (Journaled). Users with the Library sitting on disks otherwise formatted regularly report issues including, but not limited to, importing, exporting, saving edits and sharing the photos.
See this article
for more. Note also the comment:
“Additionally, storing the iPhoto library on a network rather than locally on your computer can also lead to poor performance or data loss.”
So, before we can start to figure out a solution you'll need to confirm that the library is on a correctly formatted disk and with a wired connection to the Mac.
Then tell us the size of the Library in the Finder.