执行

		
		
			
			
				alter system set db_2k_cache_size = 100M; 
			

			
				alter system set db_16k_cache_size = 100M; 
			

			
				alter system set db_32k_cache_size = 100M;

出现

			
			
				
				
					ORA-00384: 没有足够的内存来增加高速缓存的大小

的错误;

修改MEMORY_TARGET或者SGA_TARGET的过程出现过错误：

		
		
			
			
				ORA-00845: MEMORY_TARGET not supported on this system

导致系统无法启动。

这是因为修改后导致了/dev/shm>sga_max_size>memory_target平衡的缺失，或者memory_max_target等的设置错误，

重新指定spfile到pfile

CREATE SPFILE

FROM PFILE = 'r/u01/app/oracle/admin/orcl/pfile/init.ora.22020150406';

使之正常开机。

首先查询并修改/dev/shm即ShareMemory

	
	
		
		
			[root@lhd dev]# cd /etc 
		

		
			[root@lhd etc]# cat fstab  
		

		
			 
		

		
			# 
		

		
			# /etc/fstab 
		

		
			# Created by anaconda on Fri Mar 20 05:32:38 2015 
		

		
			# 
		

		
			# 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_lhd-lv_root / ext4    defaults 1 1 
		

		
			UUID=8cd309cb-24db-40c9-aedd-f28516f9f652 /boot                   ext4    defaults 1 2 
		

		
			/dev/mapper/vg_lhd-lv_swap swap                    swap    defaults 0 0 
		

		
			tmpfs /dev/shm                tmpfs   size=2G 0 0 
		

		
			devpts /dev/pts                devpts  gid=5,mode=620 0 0 
		

		
			sysfs /sys                    sysfs   defaults 0 0 
		

		
			proc /proc                   proc    defaults 0 0

		
		
			
			
				[root@lhd shm]# cat /etc/fstab | grep shm 
			

			
				tmpfs                   /dev/shm                tmpfs   size=2G        0 0 
			

			
				[root@lhd shm]# df -h /dev/shm 
			

			
				Filesystem            Size  Used Avail Use% Mounted on 
			

			
				tmpfs                 2.0G  959M  1.1G  47% /dev/shm

		
		
			
			
				SQL> show parameter memory 
			

			
				 
			

			
				NAME				     TYPE	 VALUE 
			

			
				------------------------------------ ----------- ------------------------------ 
			

			
				hi_shared_memory_address	     integer 0 
			

			
				memory_max_target		     big integer 1600M 
			

			
				memory_target			     big integer 1600M 
			

			
				shared_memory_address		     integer 0 
			

		

		
			  
		

		
			  
		

		
			
			
				SQL> show parameter cache 
			

			
				 
			

			
				NAME				     TYPE	 VALUE 
			

			
				------------------------------------ ----------- ------------------------------ 
			

			
				client_result_cache_lag 	     big integer 3000 
			

			
				client_result_cache_size	     big integer 0 
			

			
				db_16k_cache_size		     big integer 112M 
			

			
				db_2k_cache_size		     big integer 112M 
			

			
				db_32k_cache_size		     big integer 112M 
			

			
				db_4k_cache_size		     big integer 112M 
			

			
				db_8k_cache_size		     big integer 0 
			

			
				db_cache_advice string ON 
			

			
				db_cache_size			     big integer 0 
			

			
				db_flash_cache_file string 
			

			
				db_flash_cache_size		     big integer 0 
			

			
				 
			

			
				NAME				     TYPE	 VALUE 
			

			
				------------------------------------ ----------- ------------------------------ 
			

			
				db_keep_cache_size		     big integer 0 
			

			
				db_recycle_cache_size		     big integer 0 
			

			
				object_cache_max_size_percent	     integer 10 
			

			
				object_cache_optimal_size	     integer 102400 
			

			
				result_cache_max_result 	     integer 5 
			

			
				result_cache_max_size		     big integer 4M 
			

			
				result_cache_mode string MANUAL 
			

			
				result_cache_remote_expiration	     integer 0 
			

			
				session_cached_cursors		     integer 50 
			

			
				SQL> show parameter memory

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
hi_shared_memory_address	     integer	 0
memory_max_target		     big integer 1600M
memory_target			     big integer 1600M
shared_memory_address		     integer	 0

通过修改linux的/dev/shm和Oracle的Memory_target后解决

ITPub博客

alter system set db_nk_cache_size = XX导致的ORA-00845