About the problem that the database cannot be started after modifying the value of memory_target

Operating system: RHEL6.5

Database version: 11.2.0.4 When



I installed the could control software, I modified some parameters of the database, including the value of memory_target.



Then the database can't get up

SQL> startup;

ORA-00838: Specified value of MEMORY_TARGET is too small, needs to be at least 3072M

ORA-01078: failure in processing system parameters



The reason for the error is that the value of MEMORY_TARGET is too small, at least 3072M

Modifying the value of MEMORY_TARGET is inoperable in the database,

so I modify it in the parameter file



First generate pfile

SQL>create pfile from pfile;





[oracle@hzmcorcl dbs]$ vi /oracle/app/product/11.2.0/db_1/dbs/ initorcl.ora

modify the value of memory_target:

*.memory_target=3221225472





and then use pfile to start try:

SQL> startup pfile='/oracle/app/product/11.2.0/db_1/dbs/initorcl.ora';

ORA-00845: MEMORY_TARGET not supported on this system



has become a new error. The value of this MEMORY_TARGET exceeds the maximum memory of the system.

After checking the system memory, I found that the system memory is 2GB



because I am on a virtual machine, so after shutting down the operating system, I modified the memory to 4.5GB in the virtual machine,

then started the operating system, and tried again:

SQL> startup pfile='/oracle /app/product/11.2.0/db_1/dbs/initorcl.ora';

ORA-00845: MEMORY_TARGET not supported on this system



still reports this error, query on the search engine and know that

the value of MEMORY_TARGET is less than the value in /dev/shm value.

So I want to change the value of /dev/shm to make it possible to start

[root@hzmcorcl ~]# cd /etc/

[root@hzmcorcl etc]# vi fstab

# /etc/fstab

# Created by anaconda on Mon Nov 21 10 :19:33 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_hzmcorcl-lv_root /                       ext4    defaults        1 1

UUID=5845465a-e313-4337-865c-c87853677c49 /boot                   ext4    defaults        1 2

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

tmpfs                   /dev/shm                tmpfs   defaults,size=3072M        0 0

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

sysfs                   /sys                    sysfs   defaults        0 0

proc                    /proc                   proc    defaults        0 0

/dev/sdb1               /sdb                    ext4    defaults        1 2

/dev/vg1/data           /agent                  ext4    defaults        1 2



增加参数size=3072M

重新挂载：

[root@hzmcorcl etc] mount -o remount /dev/shm

[root@hzmcorcl ~]# mount -l

/dev/mapper/vg_hzmcorcl-lv_root on / type ext4 (rw)

proc on /proc type proc (rw)

sysfs on /sys type sysfs (rw)

devpts on /dev/pts type devpts (rw,gid=5,mode=620)

tmpfs on /dev/shm type tmpfs (rw,size=3072M)

/dev/sda1 on /boot type ext4 (rw)

/dev/sdb1 on /sdb type ext4 (rw)

/dev/mapper/vg1-data on /agent type ext4 (rw)

none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)



You can see that the value of /dev/shm has become 3072M (of course restarting can also take effect the modified memory value of /dev/shm)



Try to start the database again:

SQL> startup pfile='/oracle/app/product/11.2.0 /db_1/dbs/initorcl.ora';

ORACLE instance started.



Total System Global Area 3206836224 bytes

Fixed Size 2257520 bytes

Variable Size 1996492176 bytes

Database Buffers 1191182336 bytes

Redo Buffers 16904192 bytes

Database mounted.

Database opened.





At this point, database repair is complete.



Generate a new parameter file.