http://blog.csdn.net/taiyang1987912/article/details/41695895
1. Problems
When installing a virtual machine, the system does not set the swap size or set the memory to be too small, and the compiler will have the problem of virtual memory exhausted: Cannot allocate memory. You can use swap to expand the memory.
Second, the solution
When executing free -m, it prompts Cannot allocate memory:
(The swap file can be placed in your favorite location such as /var/swap)
- [root@Byrd byrd]# free -m
- total used free shared buffers cached
- Mem: 512 108 403 0 0 28
- -/+ buffers/cache: 79 432
- Swap: 0 0 0
- [root@Byrd ~]# mkdir /opt/images/
- [root@Byrd ~]# rm -rf /opt/images/swap
- [root@Byrd ~]# dd if=/dev/zero of=/opt/images/swap bs=1024count=2048000
- 2048000+0 records in
- 2048000+0 records out
- 2097152000 bytes (2.1 GB) copied, 82.7509 s, 25.3 MB/s
- [root@Byrd ~]# mkswap /opt/images/swap
- mkswap: /opt/images/swap: warning: don't erase bootbits sectors
- on whole disk. Use -f to force.
- Setting up swapspace version 1, size = 2047996 KiB
- no label, UUID=59daeabb-d0c5-46b6-bf52-465e6b05eb0b
- [root@hz mnt]# swapon /opt/images/swap
- [root@hz mnt]# free -m
- total used free shared buffers cached
- Mem: 488 481 7 0 6 417
- -/+ buffers/cache: 57 431
- Swap: 999 0 999
The memory is too small, increasing the memory can solve it.
You can turn off swap after use:
- [root@hz mnt]# swapoff swap
- [root@hz mnt]# rm -f /opt/images/swap
The swap file can also not be deleted and kept for future use. The key is that your virtual machine hard disk is sufficient.