OS/centos

swap memory 해소

물방울시드 2023. 2. 10. 17:05

[기본]

 

#메모리확인
free -h

#스왑메모리off
swapoff -a

#스왑메모리on
swapon -a

 

위 명령어로 해소되면 좋으나 swapoff failed: Cannot allocate memory 에러를 발생하면 아래 내용 실행

 

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#/home/swapfile4G 라는 임시 스왑메모리 파일 생성(4GB)
dd if=/dev/zero of=/home/swapfile4G bs=1MiB count=4096
(아래내용출력)
4096+0 records in
4096+0 records out
4294967296 bytes (4.3 GB) copied, 3.34427 s, 1.3 GB/s

#권한변경
chmod 600 /home/swapfile4G

#스왑포맷변경
mkswap /home/swapfile4G
(아래내용출력)
Setting up swapspace version 1, size = 4194300 KiB
no label, UUID=74ea8b2e-28e5-41e7-9b97-e08c1218d3b8

#스왑메모리등록
swapon /home/swapfile4G

#스왑메모리확인
swapon -s
(아래내용출력)
Filename                                Type            Size    Used    Priority
/dev/dm-1                               partition       2097148 2097124 -2
/home/swapfile4G                        file    4194300 0       -3

#메모리확인 - 이전보다 4기가 늘어나있음
free -h

#기존에 등록되어있던 스왑메모리 해제 - 스왑메모리가 많이 사용중이라면 오래걸림
swapoff /dev/dm-1

#메모리확인 - 기존 스왑메모리 줄어듬(해당서버는 2기가 줄어듬)
free -h

#기존 스왑메모리 재등록
swapon /dev/dm-1

#메모리 확인 - 다시 6기가됨
free -h

#임시 스왑메모리 해제
swapoff /home/swapfile4G

#임시 스왑메모리 삭제
rm -rf /home/swapfile4G

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새로등록한 스왑메모리 계속 이용하는방법(재부팅후에도)

vi /etc/fstab

/home/swapfile4G    none    swap    defaults    0 0