After we close lightroom it automatically backs up but now looks like the online version is out of space or whatever but how can i ensure that whatever work i did stays .
Since i see certain rollbacks. Is there anyway to connect to a higher cloud backup automatically or if adobe provides the same.
LR's backup function does not copy to the cloud. The backup is locally. So, if you run out of space, it is the drive you told LR to backup to that is running out of space. You may want to delete some of the older backups since LR is not doing this on its own.
In the dialog that opens before a backup is created you can see the backup folder listed before you click on Backup.