We have been encountering an issue recently with one of our SharePoint 2010 farms. Each night around the same time one of our Site Collections is being set to Read Only. We can see this by the modified permissions and once in Central Admin you can view the Read/Only lock for the site is in action. Then by the morning time when people are using the site it has been set back to Read/Write without any user interaction.
So far we have setup logging and debugging on the SQL server where the content DB's are saved. We have backups being performed and Trans Logs but these are not scheduled anywhere near the time we see the Site Collection get set to Read Only. I have also seen that the crawl takes quite awhile for this particular Site Collection. Through various monitoring tools we have not seen any problem with the backup process or any of our maintenance tasks happening at the same time as the site is changed to the Read Only status. I have looked through the jobs around this time as well but I cannot find any that seem suspect.
Does anyone have experience with a process other than a backup that would cause this type of behavior? I have been trying to track this down for about a week now but I have not found anything like this that happens on a regular basis.
Thanks in advance
