Removing old kernels

RHEL/CentOS/Oracle 8 To remove all but the last 2 kernels you can run:# dnf remove –oldinstallonly –setopt installonly_limit=2 kernel This is a handy reference page has much more detail on managing older kernels that may be causing positives on your vulnerability scans:

Adding Your OVH Backup Space via NFS (Bare Metal Servers)

1) Allow the relevant IP or IP Blocks to have NFS access. Do this through your control panel. 2) Find the actual name of the NFS export on the backup server: showmount -e [] 3) Create the mountpoint: mkdir /backup 4) Mount to it: mount -t nfs -o _netdev,mountproto=tcp [server]:[expert path from 2] /backup 5) … [Read more…]

ESXi 6 Create Datastore on boot

I used this article, except that I used the vmkfstools -C vmfs6 -S BootDS command with the existing partition :3 (type vmfs) Also, how to license: Permanently Setting The Hostname hostnamectl set-hostname

Centos/RH 7 Reset Root Password

Further to the previous article regarding “Single User Mode” it’s worth noting that depending on your system you may require the root password to do even this. So if you’ve really, REALLY lost the root password then these handy dandy instructions just for you! 🙂

Centos 7 “Single-User” Mode

Yup, for when you’ve forgotten the root password! Rather than copy/paste the details I’ll just link to a couple of reference sources. (Cheers Darren!) Boot in single user mode on CentOS 7 / RHEL 7 Single User Mode in CentOS 7 / RHEL 7

Postfix Rate Limiting

Following on from the excellent advice here: and here: You may want to add the following: smtpd_client_event_limit_exceptions = Without it postfix defaults to smtpd_client_event_limit_exceptions = $mynetworks and won’t apply rate rules to hosts within those networks. So if your problem is internal servers hammering your relay then the limits won’t get applied. Oh, … [Read more…]

OVH vRack With Public IPs and Citrix XenServer

If you install XenServer on a dedicated server from it comes with two NICs defined. NIC1 is the “normal” bridge network that has the server public/management IP address. IF you want to add “normal” IPs that you’ve purchased then the normal OVH guides are very good. However, it’s not particularly clear how to add … [Read more…]

MySQL Backup 1.2 (MySQL 5.5+)

In the previous versions of this script you’ve had to leave the backup user password in the script, however MySQL 5.5 and above come with mysql_config_editor which allows you to store connection details in an ancryptedl file (~/.mylogin.cnf) which mysql/mysqldump/mysqladmin can use with the “–login-path=” option. For basic usage run the following, the –password prompts … [Read more…]