虚拟机缩小内存导致得问题。。。。
ORA-00845: MEMORY_TARGET not supported on this system
SQL> show parameter memory_target;
[root@hadoop_oracle ~]# umount /dev/shm
umount: /dev/shm: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
[root@hadoop_oracle ~]# fuser -km /dev/shm
/dev/shm: 2459m
vim /etc/fstab
# /etc/fstab
# Created by anaconda on Sat Oct 15 04:55:24 2016
#
# Accessible filesystems, by reference, are maintained under ‘/dev/disk‘
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/vg_avatar-lv_root / ext4 defaults 1 1
UUID=a985db15-b14a-459b-bdc3-be5baeaf3b17 /boot ext4 defaults 1 2
/dev/mapper/vg_avatar-lv_swap swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults,size=3G 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
~
启动OK
原文：http://www.cnblogs.com/xhwangspark/p/6789944.html