LINUX下安装ORACLE时SWAP不足的两种解决方法
当前磁盘分区及SWAP分区情况如下：
[root@bys3 ~]# fdisk -l
Disk /dev/sda: 21.4 GB, 21474836480 bytes255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2078 16587112+ 83 Linux
/dev/sda3 2079 2600 4192965 82 Linux swap / Solaris
[root@bys3 ~]# free -m
total used free shared buffers cached
Mem: 2013 1850 163 0 131 1274
-/+ buffers/cache: 444 1568
Swap: 4094 0 4094
增加SWAP交换分区有两种方法：关于tmpfs的使用详见：http://blog.csdn.net/haibusuanyun/article/details/17199617 点击打开链接
1. 使用dd命令新建一个文件并挂载为SWAP
2. 增加一个新交换分区
增加的步骤都是：
1.free ---查看内存状态命令，可以显示memory，swap，buffer cache等的大小及使用状况；
2.dd ---读取，转换并输出数据命令；fdisk切分新分区
3.mkswap ---设置交换区
4.swapon ---启用交换区，相当于mount；swapoff ---关闭交换区，相当于umount
5.设置开机自动挂载/etc/fstab
1.使用DD命令创建一个文件
[root@bys3 ~]# dd if=/dev/zero of=/root/swap bs=1024 count=1024000 ---这里 bs=是bytes, count是 blocks 个块，这里的就是 1024bytes=1K，1024000K=1000M1024000+0 records in
1024000+0 records out
1048576000 bytes (1.0 GB) copied, 43.5605 seconds, 24.1 MB/s
[root@bys3 ~]# mkswap /root/swap
Setting up swapspace version 1, size = 1048571 kB
[root@bys3 ~]# swapon /root/swap
[root@bys3 ~]# free -m
total used free shared buffers cached
Mem: 2013 1864 149 0 37 1389
-/+ buffers/cache: 436 1577
Swap: 5094 0 5094 - -与最开始的相比，增加了近1000M。
设置开机自动挂载-
[root@bys3 ~]# vi /etc/fstab
LABEL=/ / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
LABEL=SWAP-sda3 swap swap defaults 0 0
/root/swap swap swap defaults 0 0
[root@bys3 ~]# mount -a --无报错，修改/etc/fstab成功
重启后查看：--SWAP空间包含了新增加的空间。
[oracle@bys3 ~]$ free -m
total used free shared buffers cached
Mem: 2013 214 1799 0 15 150
-/+ buffers/cache: 48 1964
Swap: 5094 0 5094
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2.用FDISK将未使用的分区格式化并挂载为SWAP分区
[root@bys3 ~]# fdisk -lDisk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2078 16587112+ 83 Linux
/dev/sda3 2079 2600 4192965 82 Linux swap / Solaris
[root@bys3 ~]# fdisk /dev/sda
The number of cylinders for this disk is set to 2610.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Command (m for help ): p
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2078 16587112+ 83 Linux
/dev/sda3 2079 2600 4192965 82 Linux swap / Solaris
Command (m for help) : n
Command action
e extended
p primary partition (1-4)
e
Selected partition 4
First cylinder (2601-2610, default 2601):
Using default value 2601
Last cylinder or +size or +sizeM or +sizeK (2601-2610, default 2610): +50m ---新增加个50M的扩展分区。
Command (m for help) : p
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2078 16587112+ 83 Linux
/dev/sda3 2079 2600 4192965 82 Linux swap / Solaris
/dev/sda4 2601 2607 56227+ 5 Extended
Command (m for help ): n
First cylinder (2601-2607, default 2601):
Using default value 2601
Last cylinder or +size or +sizeM or +sizeK (2601-2607, default 2607):
Using default value 2607
Command (m for help ): p
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 2078 16587112+ 83 Linux
/dev/sda3 2079 2600 4192965 82 Linux swap / Solaris
/dev/sda4 2601 2607 56227+ 5 Extended
/dev/sda5 2601 2607 56196 83 Linux
Command (m for he lp): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.
[root@bys3 ~]# free -m
total used free shared buffers cached
Mem: 2013 218 1795 0 15 153
-/+ buffers/cache: 49 1964
Swap: 5094 0 5094
[root@bys3 ~]# swapoff /root/swap 关闭一个SWAP空间
[root@bys3 ~]# free -m
total used free shared buffers cached
Mem: 2013 218 1795 0 15 153
-/+ buffers/cache: 49 1964
Swap: 4094 0 4094
[root@bys3 ~]# mkswap /dev/sda5
/dev/sda5: No such file or directory
[root@bys3 ~]# partprobe --- 同步下分区表的意思
Warning: Unable to open /dev/sr0 read-write (Read-only file system). /dev/sr0 has been opened read-only.
Segmentation fault
[root@bys3 ~]# mkswap /dev/sda5
Setting up swapspace version 1, size = 57540 kB
[root@bys3 ~]# swapon /dev/sda5
[root@bys3 ~]# free -m
total used free shared buffers cached
Mem: 2013 218 1795 0 15 153
-/+ buffers/cache: 49 1964
Swap: 4149 0 4149
###############
开机时自动挂载的配置
LABEL=/ / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
LABEL=SWAP-sda3 swap swap defaults 0 0
/dev/sda5 swap swap defaults 0 0
"/etc/fstab" 8L, 568C written
[root@bys3 ~]# mount -a
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