https://documentation.cpanel.net/display/CKB/The+checkallsslcerts+Script
Category: Sysadmin
How Vlan works in plain language
To understand how VLANs work, let’s consider VLAN applications in a traditional IT environment, where physical hosts are attached to a physical switch, and no virtualization is involved. Imagine a scenario where you want three isolated networks but you only have a single physical switch. The network administrator would choose three VLAN IDs, for example,… Continue reading How Vlan works in plain language
Docker under the hood
Many people think that docker is a kind of monolithic system and they hardly understand how internally it works. see the figure below
checking who is connecting with nfs server
cat /var/lib/nfs/rmtab
Fixed sysctl: cannot stat /proc/sys/net/bridge/bridge-nf-call-iptables:
sysctl: cannot stat /proc/sys/net/bridge/bridge-nf-call-iptables: No such file or directory sysctl: cannot stat /proc/sys/net/bridge/bridge-nf-call-ip6tables: No such file or directory solution: modprobe br_netfilter
slashargument no image css appear issue in moodle 2.9+ nginx FIXED
location ~ [^/]\.php(/|$) { fastcgi_split_path_info ^(.+\.php)(/.+)$; fastcgi_index index.php; fastcgi_pass 127.0.0.1:9000 (or your php-fpm socket); include fastcgi_params; fastcgi_param PATH_INFO $fastcgi_path_info; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; }
ipmitool dev not found
modprobe ipmi_devintf modprobe ipmi_si You can add these to /etc/modules to have them loaded automatically (just list the module names): ipmi_devintf ipmi_si
linux gateway
iptables -A FORWARD -i eth1 -j ACCEPT iptables -A FORWARD -o eth1 -j ACCEPT iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE #ETHO where internet is connected
Get MD5 checksum hash of big files in Python
def checkHash(filename, blocksize=2**20): try: print(“need to creating hash of file ” +filename) m = hashlib.md5() with open(filename , “rb” ) as f: while True: buf = f.read(blocksize)… Continue reading Get MD5 checksum hash of big files in Python
cinder volume service down fixed
it is mostly date issue check date on both controller and cinder-volume server and do ntpdate 1.ubuntu.pool.ntp.org