The OP didn't ask how he could just backup his db. That's only a small part of backing up a vbulletin installation. Unless maybe you've got all your attachments in the db, but that's really only possible on the smallest of forums.

i dont have a ftp access and cpanel or directadmin and its a big board.
So i cant backup it form the admincp

You dont have FTP access to your own hosting account, how did you set it up in the first place then?

I would suggest you find a new host as soon as you get a backup of your DB made.

Seeing as you can't upload anything, that creates quite the issue in terms of getting a valid backup from the host server.

Did you try dumping the larger tables separately to avoid the php timeout?

This is my friend host,
and he gave me an administrator acc.
And this is why i dont have ftp and cpanel access

Sorry, you cannot function as a full admin without full access. There are many tasks, backups included, that you will not be able to do.

For security reasons, as few people as possible should have this full access. As long as the super admin at your forum is taking care of the backups and updating, I wouldn't worry about it.

That script will time out during the backup of large databases.

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PaulM made a nice backup script, but you have to have ftp access to download the backup files.

After the one released by Paul, I use mysqldumper to backup my smaller databases. But mysqldumper seems to have problems with databases over about 700 or 800 megs.

You're out of luck, then. If he doesn't give you full access you can't do certain things (like backing up the database).

ohh
Tnx anyway i will talk to him to give me access