Linux Redhat 7.9关闭内存管理特性

1 关闭大页内存

$root@db1 \~$ # cat /sys/kernel/mm/transparent_hugepage/defrag

$always$ madvise never

$root@db1 \~$ # cat /sys/kernel/mm/transparent_hugepage/enabled

$always$ madvise never

echo never > /sys/kernel/mm/transparent_hugepage/enabled

echo never > /sys/kernel/mm/transparent_hugepage/defrag

cat /sys/kernel/mm/transparent_hugepage/defrag

cat /sys/kernel/mm/transparent_hugepage/enabled

chmod u+x /etc/rc.d/rc.local (忘记加权限了导致多次重启主机shit)

echo 'echo never > /sys/kernel/mm/transparent_hugepage/defrag' >> /etc/rc.d/rc.local

echo 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' >> /etc/rc.d/rc.local

3. 验证是否关闭了透明大页

$root@eomsdb1 \~$ # grep Huge /proc/meminfo

AnonHugePages: 83968 kB

HugePages_Total: 0 #success

HugePages_Free: 0

HugePages_Rsvd: 0

HugePages_Surp: 0

Hugepagesize: 2048 kB

$root@eomsdb1 \~$ # cat /proc/sys/vm/nr_hugepages

0

#success

2 开启大页内存

echo always > /sys/kernel/mm/transparent_hugepage/enabled

echo always > /sys/kernel/mm/transparent_hugepage/defrag

cat /sys/kernel/mm/transparent_hugepage/defrag

cat /sys/kernel/mm/transparent_hugepage/enabled

3 禁用numa特性

一、检查OS是否开启NUMA

复制代码

# cat /proc/cmdline
root=LABEL=DBSYS ro bootarea=dbsys rhgb quiet console=ttyS0,115200n8 console=tty1 crashkernel=128M@16M numa=off
# numactl --hardware

dmesg|grep -i numa

备份numa文件

cp /etc/default/grub /etc/default/grub2023bak

vi /etc/default/grub

在 GRUB_CMDLINE_LINUX 参数的末尾增加： numa=off

例如：

GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=vg_root/root rd.lvm.lv=vg_root/swap rhgb quiet numa=off"

重建grub 配置文件

MBR 分区表

grub2-mkconfig -o /etc/grub2.cfg

efi 引导模式， efi + GPT分区表

grub2-mkconfig -o /etc/grub2-efi.cfg

重启机器，再来检查numa 是否被关闭即可

dmesg|grep -i numa