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 / ZFS
This is the tale of caution, when sleep deprived, sysadmin with caution! Let’s be honest who never said : lets finish this game, let’s have another drink, I will sleep when dead, … (enter sleepless night excuse here) ? Last night for me I was on a coding spree, when a thunderstorm broke, I was […]
After a reboot, I got greeted with this error : [email protected]:~# zpool status pool: rpool state: DEGRADED status: One or more devices could not be used because the label is missing or invalid. Sufficient replicas exist for the pool to continue functioning in a degraded state. action: Replace the device using ‘zpool replace’. see: http://zfsonlinux.org/msg/ZFS-8000-4J […]
I recently revived a “old” compute cluster. While its hardware was formidable back in the day, now it has been replaced with a younger version, which has more compute nodes. I wanted to create a data partition of two disks, normally I have a raid controller but on this server, there is none. An open invitation for […]
Installing ZFS on Centos has been ironed out pretty much, so just follow along. There are three ways I know of to install ZFS on Centos. The two methods are recommended, as they use a repository, the last is just compiling from source, which I like, since I decide when its updated. (as kernel updates […]
After the fairy dust has settled on Let’s Encrypt, allot of good solutions are out there to get a valid certificate using the ACME protocol (see client list). Most of the technique’s use webroot as verification technique, while this is fine for most websites, it has some downsides. For one, you need to adapt (let […]
Tuning of ZFS module The more difficult part of ZOL is the fact that there are plenty of tune able kernel module parameters, and hence ZFS can be used in many kinds of systems for many different reasons. (laptops, file-servers, database-servers, file-clusters) However some of the parameters come bad out of the box for file […]
Lets start out with saying that ZFS on Linux (ZoL) is pretty awesome, snapshots, compression-on-the-fly, quota’s, … I love it. However ZoL also has issue’s, I even blogged about some in the past. (a full ZFS pool, failing to load ZFS module) Most cases where my own fault, but still, its very uncommon for a file system […]
One of the impressive tools in ZOL (ZFS On Linux) is snapshots. Snapshots are a way to make a ‘instant backup’ of the files on the system. The name backup, is not completely correct. If the system dies, the snapshots won’t save you, since snapshots are on the same storage as the data, they don’t eat […]