[root@node1 ~]# cat /etc/fstab

#

# /etc/fstab

# Created by anaconda on Mon Mar  1 18:32:15 2021

#

# Accessible filesystems, by reference, are maintained under '/dev/disk'

# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info

#

/dev/mapper/centos-root /                       xfs     defaults        0 0

UUID=3fa2b010-61bc-480e-bd49-cb7bee120fe3 /boot                   xfs     defaults        0 0

/dev/mapper/centos-swap swap                    swap    defaults        0 0

[root@node1 ~]#

sed -i '/swap/s/^/#/g' fs.txt

[root@node1 ~]# diff fs.txt /etc/fstab

11c11

< #/dev/mapper/centos-swap swap                    swap    defaults        0 0

---

> /dev/mapper/centos-swap swap                    swap    defaults        0 0

[root@node1 ~]# cat /etc/fstab

until grep swap fs.txt  |grep "#" >/dev/null;do echo "disable swap" && sed -i '/swap/s/^/#/g' fs.txt;done

until grep swap /etc/fstab  |grep "#" >/dev/null;do echo "disable swap" && sed -i '/swap/s/^/#/g' /etc/fstab;done