Magento background cannot log in

Often someone encounters Magento backstage, entered the correct account password. Do not log on properly, and do not prompt for errors. is to continue to jump to the login interface.

There are many solutions on the web, most of which are to comment out a piece of code.

I am a stand-alone server, according to the online method, annotate the code, also can not log in.

Then I emptied the cache and after the session. Can log in. But only for a while. After a few 10 minutes. Re-landing, there are problems again.

So the problem arises when allocating memory space to the Var.

At the time of Magento optimization. I used the command mount-t tmpfs-o size=100m,mode=0777 tmpfs var

is to mount the Var in memory and assign it 100M of memory space. The memory for VAR is only configured with 100M. How can this be done? var minutes to two hundred or three hundred m.

Decisively execute command mount-t tmpfs-o size=1000m,mode=0777 tmpfs var. Add the memory of Var to 1G. The problem has been solved.

Log on to FTP to view var. Takes up more than 300 m. No wonder you can't land. But assigned to 1G. It's enough. It's good to have the cache emptied periodically.