当swap内存不足时，可以用硬盘空间创建新的swap

[root@thankinglove sbin]# free -m          
             total       used       free     shared    buffers     cached
Mem:           992        923         69         12          1        306
-/+ buffers/cache:        615        377
Swap:            0          0          0
[root@thankinglove sbin]# mkdir -p /opt/p_w_picpaths
[root@thankinglove sbin]# rm -rf /opt/p_w_picpaths/swap
[root@thankinglove sbin]# dd if=/dev/zero of=/opt/p_w_picpaths/swap bs=1024 count=2048000
2048000+0 records in
2048000+0 records out
2097152000 bytes (2.1 GB) copied, 41.3215 s, 50.8 MB/s
[root@thankinglove sbin]# mkswap /opt/p_w_picpaths/swap
Setting up swapspace version 1, size = 2047996 KiB
no label, UUID=cb3463eb-fed5-448d-9727-506e874a5741
[root@thankinglove sbin]# swapon /opt/p_w_picpaths/swap
swapon: /opt/p_w_picpaths/swap: insecure permissions 0644, 0600 suggested.
[root@thankinglove sbin]# free -m
             total       used       free     shared    buffers     cached
Mem:           992        924         68         12          0        310
-/+ buffers/cache:        613        379
Swap:         1999          0       1999

当使用完毕后，可以关闭增加的swap

[root@thankinglove sbin]# swapoff /opt/p_w_picpaths/swap
[root@thankinglove sbin]# rm -rf /opt/p_w_picpaths/swap


http://blog.csdn.net/taiyang1987912/article/details/41695895