Added new brick and did a rebalance. in mount-pt do ls 
#ls -l /mnt
ls: cannot access /mnt/816: No such file or directory
ls: cannot access /mnt/4421: No such file or directory
ls: cannot access /mnt/7232: No such file or directory
ls: cannot access /mnt/6604: No such file or directory
ls: cannot access /mnt/5705: No such file or directory
ls: cannot access /mnt/2685: No such file or directory
ls: cannot access /mnt/231: No such file or directory
ls: cannot access /mnt/9398: No such file or directory
ls: cannot access /mnt/3103: No such file or directory
ls: cannot access /mnt/7780: No such file or directory
ls: cannot access /mnt/1347: No such file or directory
ls: cannot access /mnt/2158: No such file or directory

and cat says 

#cat /mnt/1
cat: /mnt/1: No such file or directory 
# cat /mnt/816
cat: /mnt/816: No such file or directory 
# cat /mnt/704
cat: /mnt/704: No such file or directory