XF 2.1 Test import of an active/running VB 3.8 forum

joshg

New member
I have a fresh install of XF2.1 that's working but with no content.
I'm ready to do a test to see what how my vbulletin forum will work in XF2.

If I want to do a test import of a RUNNING vbulletin forum, can I do it without turning off the vb forum? Or is there risk of corruption of the source DB so I really must bring down the old forum temporarily? And do I need to make a copy of the vb database before i do the test import and point the import somehow to that backup database?

Thanks
 

Kirby

Well-known member
You can perform a test import from a live database, however this import will not be consistent as the source db is being modified while the import is running.
 
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JohnLogar

Member
Simply, make a database copy and test it with it. Don't play with your existing database without backup. Further, check the manual mentioned above.
 

gerryvz

Well-known member
@JohnLogar is 100% correct.

Do a few test imports of a database backup so that you get the process and settings down.

When it comes time to do the final “real” import, take your forum down to do it so that the database is up to date.

Put the database copy you are using (NEVER import from a live/production database) on the same server as your new XF install.

The actual import process doesn’t really take all that long. It’s the process of tweaking settings and permissions that takes the time, after the actual import.
 
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Kirby

Well-known member
The actual import process doesn’t really take all that long.
That purely depends on the size of the source data, hardware and configuration.
For example importing a 10M+ vBulletin with a few hundred thousand attachments does take some time, eg. more than a few minutes.

NEVER import from a live/production database
While not recommended it's definitly doable; in fact I've done this dozens of times to do test imports - cloning a large live system just to perform a test import wasn't worth the time & resources required to do so.
 

gerryvz

Well-known member
Two thoughts:

1) No question that a larger set of source data (ie a 10GB database, 100GB of images and 100,000 users) is going to take much longer than a smaller forum (mine was 1GB database, 50GB of images and 8,100 users). And yes there are dependencies based on the hardware involved and how it's set up. My point really was that the fine-tuning and adjusting and tweaking tends to take MUCH longer than the actual import itself. I've seen this time and time again. After seven-plus months, I'm STILL finding small tweaks on permissions and such that I'm making as I go through things methodically.

2) Certainly it's POSSIBLE to import from a "live" production database -- I've done it myself. It's also POSSIBLE that something COULD POTENTIALLY go wrong with the import process, and the database is somehow corrupted or compromised. Not likely, but POSSIBLE enough to warrant a modicum of caution.

The more prudent, and safe, thing to do is to use a backup/copy of a production database, particularly for new XenForo users who may not be familiar with Linux, databases, or the XenForo importation process themselves.

One other benefit of importing from a snapshot and while a forum is shut down, is that any incremental changes that would be happening (new posts, edits, new user registrations, and so forth) while the import is going on, may not be captured by the import process itself. Whereas a "frozen" copy of the database, done after the forum is temporarily shuttered, is going to be 100% up to date and inclusive of any changes.

It's a free country - anyone can do whatever they want and can accept any level of risk they want. I'm certainly not (and certainly not technically qualified) going to tell people what to do. I'm just giving the benefit of my experience as an "advanced beginner" who has been bootstrapping himself with learning everything after 10 years doing the hosted thing.
 

Kirby

Well-known member
It's also POSSIBLE that something COULD POTENTIALLY go wrong with the import process, and the database is somehow corrupted or compromised. Not likely, but POSSIBLE enough to warrant a modicum of caution.
Yes, it's certainly possible that smth. goes wrong, but a corruption/damage of the source DB is IMHO very unlikely - the import process does not write anything, could even use a user that has only SELECT permission to be extra safe.

Having said that, I personally wouldn't recommend doing this to anyone who is asking if this is possible - those that have the expertise to deal with issues wouldn't ask ;)
 

Brogan

XenForo moderator
Staff member
If the XF installation has been configured, etc. take a backup before importing.

 

gerryvz

Well-known member
You can import from any viable and supported database -- whether a "live" production database or a snapshot/backup database.

What I found when I did my vBulletin import is that it is best if the database being imported FROM is located on the same server as the new XenForo install/import is. Same with the /images file from the vBulletin being migrated from.

I think the whole thing about using a backup is mainly for extra safety margin. Heck, I made a backup of my forum's database yesterday just before I upgraded to XF 2.1.5a ... just for extra safety margin. I guess I could've "chanced" it and not backed it up. But a backup only takes a minute or two, and the peace of mind is worth it.

Like I said, I'm only a n00b, so I just do what works for me. Others' MMV.
 

Kirby

Well-known member
There isn't any mention of being able to import from a backup.

View attachment 213272
There isn't any mention of not being able to import from a backup/copy/clone/snapshot, the manual just mentions that you need a source database.

Wether that source DB is the "live" DB on the "live master server", a MySQL replication slave, a galera node, a copy of the DB on one of those, a copy on a completely different server (maybe even on the other side of the earth connected through a VPN) doesn't really matter in terms of being able to import.

However, as already stated before, if you import from a live DB the import most likely won't be consistent.

Therefore for a real import it is recommend to close the source forum.
 
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