[EFI/UEFI/Linux] Replace a EFI boot partition

Create an EFI partition on the boot disk using gdisk. Where it exists on the disk doesn’t matter. The partition should be at least 100MB but >200MB is recommended. It is critical that the partition type is Boot Partition (type ef00). Create a filesystem on that partition. It MUST be vfat type 32. A regular vfat format […]

[Dovecot] master: Error: service(config): Initial status notification not received in 30 seconds, killing the process

If you’re running a very large dovecot config that takes a long time to load and dovecot won’t start you’re going to see this error: master: Error: service(config): Initial status notification not received in 30 seconds, killing the process In our case we have many certificates to load from the SNI configs. You’ll also see […]

[Active Directory/SSSD] [sssd[ldap_child[xxxxx]]]: Failed to initialize credentials using keytab [MEMORY:/etc/krb5.keytab]: Client ‘host/thisisaverylongdomainname.org@EXAMPLE’ not found in Kerberos database. Unable to create GSSAPI-encrypted LDAP connection.

This error can be caused by a few different reasons. In this particular case it’s a Centos 6 server connection to a Microsoft Active Directory 2016 DC. The short version of the story is that even though the FQDN has a valid key in the krb5 keytab it will only properly authenticate using the short […]

[Areca RAID] RAID configuration disappears

If you’ve had a previously configured Raid Set on an Areca RAID controller and it all of a sudden disappears it can sometimes be salvaged. In the RAID BIOS: Raid Set Function -> Rescue Raid You’re then prompted to “Enter the Operation Key.” This is ambiguous in the documentation and there’s also a mispelling for […]

[MySQL/MariaDB/CentOS 7] mysqldump: Couldn’t execute XXXXX (Errcode: 24 “Too many open files”) (23)

MySQL/MariaDB will sometimes hit its open file limit when doing large mysqldump operations. On a lot of distributions you can raise the limit by adding the following line to the /etc/my.cnf file and restarting the service: open_files_limit=XXXX This doesn’t work on systemd controlled database services so you need to add the following lines to /etc/systemd/system/mariadb.service.d/limits.conf […]

[Linux/quotacheck] quotacheck: Cannot stat directory //var/spool/exim_incoming/scan/1erAzg-0007eX-E1: No such file or directory

When running quotacheck on a filesystem that isn’t read only it will error out and not finish if it’s unable to stat a certain file or directory. It does this because it assumes that there’s a problem with the filesystem. If your mail software is actively processing mail when running quotacheck it will get an […]