K3S NFS Root howto
Using K3S and Raspberry Pi Network booting (no SD Cards). Due to NFS not supporting overlayfs in all kernels (yet), if you want to run K3S for NFS booting Pis, there is an install option you need to add INSTALL_K3S_EXEC="–snapshotter=native" to the install process. Here is a quick description of the problem and my setup in case this is of any use.
Description of the problem. Installing K3S on Network boot Raspberry Pi 3/4 Booting the Raspberry Pi cmdline.
Raspberrypi_nfsboot
Booting a Raspberry Pi from SD card, root filesystem is NFS Other documentation has recommended the following line dwc_otg.lpm_enable=0 console=tty1 root=/dev/nfs nfsroot=192.168.1.23:/data/raspbian_nfs/2020_06,tcp,rw,vers=3 ip=dhcp rootfstype=nfs elevator=deadline rootwait This kernel panicked for me each time due to the rootfstype=nfs, so after some digging, I used: console=tty1 root=/dev/nfs nfsroot=192.168.1.23:/data/raspbian_nfs/2020_06,vers=3 rw ip=dhcp rootwait elevator=deadline On the NFS server, /etc/exports contains: /data/raspbian_nfs/2020_06 192.168.1.0/24(no_root_squash,rw,async,no_subtree_check,insecure) /data/raspbian_nfs/2020_06 is populated using:
mount 192.168.1.23:/data/raspbian_nfs/2020_06 /mnt # rsync -Phax –numeric-ids / /mnt/data/raspbian_nfs/2020_06 The /etc/dhcp/dhcpd.
Mysql_max_connections
Calculating the Max connections in MySQL programmatically in one pass Sometimes you need to calculate the percentage of the maximum number of MySQL connections that are being used at any one time. Here is a piece of SQL that I’m using:
MariaDB [(none)]> SELECT VARIABLE_VALUE INTO @maxconn FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES WHERE VARIABLE_NAME="MAX_CONNECTIONS"; SELECT COUNT(1) INTO @currentconn FROM INFORMATION_SCHEMA.PROCESSLIST; SELECT (@currentconn/@maxconn)*100 AS "% Connections used"; +——————–+ | % Connections used | +——————–+ | 3.