Ever wondered what kind of checksum ZFS uses to check for bit rot ? Probably not, but it turns out you can change the used algorithm. However like most settings, the defaults are chosen by smart people. So changing it might not be doing you any favors. As it turns out, the default checksum used […]
Category / SysAdmin
I installed PHP 7.1 through webtatic, except with Apache instead of Nginx, so not the -fpm. Installing PHP stats package is easy, if you know how, so follow along. First we need to provide our system with a compiler, and the pear package which contains pecl (yum whatprovides pecl) yum install gcc php71w-pear After that you […]
I installed a new kernel (kernel-ml, from mainline 4.18) to make sure on next boot it got selected this is what I had to do : (Since its headless and I won’t see grub when it boots) Install kernel mainline : yum install kernel-ml Find the current installed kernels : cat /boot/grub2/grub.cfg | grep ^menuentry | […]
Auch, I got the same error as ma.ttias.be pretty much two years ago. I have no idea why it failed, however the solution seemed to work similar to what he suggested. [Mon Dec 03 15:07:55.871866 2018] [auth_digest:notice] [pid 3352] AH01757: generating secret for digest authentication … [Mon Dec 03 15:07:55.871892 2018] [auth_digest:error] [pid 3352] (2)No such […]
Ordinarily I use “static” references in /etc/fstab to mount NFS shares to a server. Doing this on a Rocks Cluster however is a bit “hacky” and adapting every node can be automated by using rocks run host however there is a alternative way. (not sure if its better 😉 ) but Rocks uses Autofs to load NFS […]
On Centos 7.5 base install, there are no utility’s installed by default. So when I tried to mount an NFS share I got this error : mount: wrong fs type, bad option, bad superblock on svennd.be:/data, missing codepage or helper program, or other error (for several filesystems (e.g. nfs, cifs) you might need a /sbin/mount.<type> […]
In a recovery of a system I found myself in annoying pickle of having two disks with a similar LVM layout and more precise with a equally named volume group. This can cause issues, however in my case it just stopped me from mounting the original device. To make matters worse the sizes of the […]
We bought our first 10GBase-T switch. Pretty nice, but setting it up proved a bit more complex then our SuperMicro switches. Here I documented my search to get servers to talk to each other over a VLAN using the switch to assign IP addresses, using DHCP. Login & Connect Logging in proved rather easy and […]
While updating our network on the Rocks Cluster, the nodes had to reinstall (this is default protocol). Now however the nodes got stuck during PXE (over the net automatic installation) on the setting of the language. This is annoying as it would mean connect a screen and a keyboard to every node to install. This however […]
Rocks distro is a cluster system. It comes with SNMP configured out of the box. It is polled using Ganglia. Which is working nicely, but I like to have all SNMP data in my favorite SNMP system, LibreNMS. Changing the SNMP configuration to be able to poll from LibreNMS should be a rather straight forward process, however those nodes have […]