This is command in megacli linux to blink the disk in order to locate the phisical placement of the storage. Start blinking MegaCli -pdlocate physdrv \[E:s\] a0 Stop blinking MegaCli -pdlocate stop physdrv \[252:0\] a0 If there is no disk…
D.
DDOS and Flooding Detection Apache Webserver (Updated)
List the the connection status and sort to identify attack source #netstat -anp |grep ‘tcp\|udp’ | awk ‘{print $5}’ | cut -d: -f1 | sort | uniq -c | sort –n #netstat -n | grep :80 |wc –l or check…
F.
Find the user having high Inode usage
We can find the inode usage (Number of files) owned by each user/directory, especially useful in VPS. Each VPS will have inode limits (the maximum number of files that can be created in that VPS) For example If the inode…
Z.
Zimbra Restrict user to send to local domain
This time, it’s about limiting email certain user on Zimbra to only send email to local domain on certain domain. Edit /opt/zimbra/conf/zmconfigd/smtpd_recipient_restrictions.cf and add below line after permit_sasl_authneticated check_sender_access lmdb:/opt/zimbra/postfix/conf/restricted_senders Edit /opt/zimbra/conf/zmconfigd.cf file and add line below at postfix groups…
R.
Redis Slave Replication Issue; State wait_bgsave
On our redis replication with sentinel using 3 nodes, we have issue with error below in slave each time the redis sync RDB files;==5550:S 16 Apr 2021 19:58:53.654 # I/O error trying to sync with MASTER: connection lost==Replication info shows==127.0.0.1:6379>…