Some blog owners take the "Export Blog" / "Import Blog" wizards too casually. Most computer owners enjoy multitasking - and multitasking, between various online activities which involve your personal involvement, can increase productivity.
The process of importing comments and posts, into a Blogger blog, does not involve your personal involvement - and does not work well during multitasking. Multitasking will actually slow the import process down - and what might take mere minutes can take hours, or days.
Too many computer owners, accustomed to doing several things at once on a given computer, may casually add the process of importing a set of comments and posts into a blog, as just one more task.
Most Internet tasks - such as chatting with family and friends, reading and sending email, and web surfing in general - run at your speed. If you're busy chatting, the email task sits idle in the background. Likewise if you are reading email, you may not be doing a lot of web surfing.
The task of importing comments and posts into a blog, on the other hand, runs without your involvement. On a well maintained computer, with nothing else to do, a moderate sized ".xml" file can take just minutes to upload to your blog. The key here is "nothing else to do".
There are various computer activities.
- Reading and writing content, locally ("disk" activity).
- Reading and writing content, using the Internet ("network" activity).
- Processing content read, into content written ("CPU" activity).
Since you do not have anything to do while a blog is being exported to a local file - or a local file is being imported to a blog - you may be tempted to spend your time chatting, reading / writing email, or surfing the web.
If you have only one computer, this may be a bad decision. Anything that you may do, which involves your action on the computer - chatting with family and friends, reading and sending email, and web surfing in general - is going to require CPU, disk, memory, and / or network resources.
Anything that competes with an export or import task, for resources, is going to make the export / import task run slower. In extreme cases, a task that should take minutes can end up taking hours - or even days - to complete.
One other way to make the import process run slower is to publish posts, as you import. This will, at best, cut import speed in half - and probably have a worse effect. Resist the temptation to select "Automatically publish all imported posts", when importing.
The next time that you export your blog to a local file - or import from a local file to a blog - try using a second computer - or take the afternoon off from any Internet activity. And close all browser tabs and windows, excepting the one where you are actually running the export or import.
If you lighten the load, of all non essential tasks, you may find that the export / import task runs faster than you expected - and you may be able to get back to your chatting with family and friends, reading and sending email, and web surfing in general, a lot sooner than you would have expected.