增加虚拟内存的两种方法
#查看当前虚拟内存信息
[/var/ftp/ks]#swapon -s Filename Type Size Used Priority /dev/sda2 partition 2096472 92 -1
#添加虚拟内存
#1.通过分区增加
[/var/ftp/ks]#fdisk -l 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 2349 18868311 83 Linux /dev/sda2 2350 2610 2096482+ 82 Linux swap / Solaris Disk /dev/sdb: 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/sdb1 1 123 987966 8e Linux LVM /dev/sdb2 124 246 987997+ 8e Linux LVM /dev/sdb3 247 369 987997+ 8e Linux LVM /dev/sdb4 370 2610 18000832+ 5 Extended /dev/sdb5 370 492 987966 8e Linux LVM
[/var/ftp/ks]#fdisk /dev/sdb 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/sdb: 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/sdb1 1 123 987966 8e Linux LVM /dev/sdb2 124 246 987997+ 8e Linux LVM /dev/sdb3 247 369 987997+ 8e Linux LVM /dev/sdb4 370 2610 18000832+ 5 Extended /dev/sdb5 370 492 987966 8e Linux LVM Command (m for help): n First cylinder (493-2610, default 493): Using default value 493 Last cylinder or +size or +sizeM or +sizeK (493-2610, default 2610): +500M Command (m for help): p Disk /dev/sdb: 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/sdb1 1 123 987966 8e Linux LVM /dev/sdb2 124 246 987997+ 8e Linux LVM /dev/sdb3 247 369 987997+ 8e Linux LVM /dev/sdb4 370 2610 18000832+ 5 Extended /dev/sdb5 370 492 987966 8e Linux LVM /dev/sdb6 493 554 497983+ 83 Linux #修改标签为82，即交换分区标示 Command (m for help): t Partition number (1-6): 6 Hex code (type L to list codes): 82 Changed system type of partition 6 to 82 (Linux swap / Solaris) Command (m for help): 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.
#刷新分区信息
[/var/ftp/ks]#partprobe /dev/sdb [/var/ftp/ks]#mkswap /dev/sdb6 Setting up swaace version 1, size = 509927 kB
#增加分区为交换
[/var/ftp/ks]#swapon /dev/sdb6 [/var/ftp/ks]#swapon -s Filename Type Size Used Priority /dev/sda2 partition 2096472 76 -1 /dev/sdb6 partition 497972 0 -2
#修改优先级，-p指定优先级范围0-32767，越大越优先。
[/var/ftp/ks]#swapoff /dev/sdb6 [/var/ftp/ks]#swapon -p 5 /dev/sdb6 [/var/ftp/ks]#swapon -s Filename Type Size Used Priority /dev/sda2 partition 2096472 76 -1 /dev/sdb6 partition 497972 0 5 [/var/ftp/ks]#vi /etc/fstab LABEL=/ / ext3 defaults 1 1 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-sda2 swap swap defaults 0 0 "/etc/fstab" 8L, 598C written
#2.通过文件增加
#创建一个文件，格式化为swap格式
[/var/ftp/ks]#dd if=/dev/zero of=/home/swapfile bs=1024 count=1024 1024+0 records in 1024+0 records out 1048576 bytes (1.0 MB) copied, 0.00702343 seconds, 149 MB/s [/var/ftp/ks]#mkswap /home/swapfile Setting up swaace version 1, size = 1044 kB
#启用文件作为swap
[/var/ftp/ks]#swapon /home/swapfile [/var/ftp/ks]#swapon -s Filename Type Size Used Priority /dev/sda2 partition 2096472 76 -1 /dev/sdb6 partition 497972 0 5 /home/swapfile file 1016 0 -3