[Oracle problem set 1] ORA-00845: MEMORY_TARGET not supported on this s

[Oracle problem set 1] ORA-00845: MEMORY_TARGET not supported on this system execution statement: Start Oracle Database (startup) error: ORA-00845: MEMORY_TARGET not supported on this system error cause: because the size of SGA exceeds the size of the Operating System/dev/shm, solution: first, modify the initialization parameter so that the size of SGA in the initialization parameter is smaller than/dev/shm. the second method is to adjust/dev/shm as follows: [root @ localhost ~] # Vim/etc/fstab tmpfs/dev/shm tmpfs ults, size = 10240 M 0 0 [modify tmpfs size] [root @ localhost ~] # Umount/dev/shm [root @ localhost ~] # Mount/dev/ssh [root @ localhost ~] # Df-h/dev/shm file system capacity in use available % mount point tmpfs 10G 0 10G 0%/dev/shm knowledge A, tmpfs has the following features: tmpfs is a file system, not a block device. You just install it and it can be used. The size of the dynamic file system. Another major benefit of tmpfs is its lightning speed. Because the typical tmpfs file system will completely reside in RAM, reading and writing can be almost instantaneous. Tmpfs data will not be retained after restart, because the virtual memory is essentially easy to lose. Therefore, it is necessary to perform some script operations such as loading and binding. B. linux/dev/shm default capacity in linux/dev/shm the default capacity is up to half the memory size. You can see it by running the df-h command. But it does not really occupy this memory. If there is no file in/dev/shm/, it actually occupies 0 bytes of memory. If it is 1 GB at the maximum, if there is a M file in it, the remaining m can still be used by other applications, but the M memory it occupies will never be recycled and re-divided by the system, otherwise, who dared to store files in it? Run df-h to view the linux/dev/shm Size [root @ db1 shm] # df-h/dev/shm Filesystem Size Used Avail Use % Mounted on tmpfs 1.5G 0 1.5G 0%/dev/shm C. linux/dev/shm capacity (size) Adjustment linux/dev/shm capacity (size) can be adjusted, in some cases (such as oracle Database) the default maximum half of the memory is not enough, in addition, the default inode quantity is very low. Generally, you need to increase the inode quantity. You can use the mount command to manage it. Mount-o size = 1500 M-o nr_inodes = 1000000-o noatime, nodiratime-o remount/dev/shm on 2 GB machines, and the maximum capacity is adjusted to 1.5 GB, in addition, the inode quantity is adjusted to 1000000, which means that up to 1 million small files can be saved to change the/dev/shm capacity through the/etc/fstab file (you can add the size option ), after modification, Remount the disk: [root @ db1 shm] # grep tmpfs/etc/fstab tmpfs/dev/shm tmpfs defaults, size = 2G 0 0 [root @ db1/] # umount/dev/shm [root @ db1/] # mount/dev/shm [root @ db1/] # df-h /dev/shm Filesystem Size Used Avail Use % Mounted on tmpfs 2.0G 0 2.0G 0%/dev/shm [root @ db1/] # mount-o remount/dev/shm [root @ db1/] # df-h Filesystem Size Used Avail Use % Mounted on/dev/mapper/rootvg-lv01 97G 9.2G 83G 10% // dev/sda1 99 M 15 M 80 M 16%/boot tmpfs 2.0G 0 2.0G 0%/dev/shm