Uly.me

cloud engineer

redhat

Create Swap Disk

To see which disk is available for swap disk use.

lsblk
blkid
df -Th

Format the disk.

fdisk /dev/xvda

Create a swap disk.

sudo mkswap -f /dev/xvda
sudo swapon -s /dev/xvda
# or
sudo swapon /dev/xvda

Check if swap disk is available.

lsblk
free -h 
cat /proc/swaps
cat /proc/meminfo
swapon -s
top
vmstat
vmstat 1 5

Apache & Webroot

Where’s Apache and webroot for the different distros?

Webroot:

# Redhat, Fedora, Centos, Amazon Linux
/var/www/html
# Debian, Ubuntu, Mint
/var/www/html

Apache Configuration:

# Redhat, Fedora, Centos, Amazon Linux
/etc/httpd/conf/httpd.conf
# Debian, Ubuntu, Mint
/etc/apache2/sites-available/default

Yum Remove Repo

How to remove repos in Yum. Just delete the repo file in /etc/yum.repos.d.

rm /etc/yum.repos.d/repo-name.repo

ReiserFS

Install ReiserFS

rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh https://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
yum update
yum install kmod-reiserfs kmod-reiserfs

Make a ReiserFS

fdisk /dev/xvdf
n, p, 1
[return]
[return]
mkreiserfs /dev/xvdf1
mount -t reiserfs /dev/xvdf1 /data

Other Reiserfs commands

reiserfsck /dev/xvdf1
resize_reiserfs /dev/xvdf1