I’m a fan of ZFS filesystem. It’s so good that I also use ZFS on most my Linux machines, though it’s painful at time when the ZFS kernel modules fail to compile. Why I like it so much comparing to other file system such as XFS, EXT4, BTRFS? ZFS allows me to quickly do snapshots and efficiently send snapshots over the network, and my nas runs FreeBSD which support ZFS natively. ...
ZFS is one of my favorite file systems. I use it at home on my nas server (running FreeBSD) as well as my Fedora 32 desktop. Today, I’m going to show you (and my future self) how to replace a (faulty) disk in a Zpool. The server I’ll be working on is nas2 and the pool is tank. List the status of the current pool. Password: root@nas2:~ # zpool status tank pool: tank state: DEGRADED status: One or more devices could not be opened. Sufficient replicas exist for the pool to continue functioning in a degraded state. action: Attach the missing device and online it using 'zpool online'. see: http://illumos.org/msg/ZFS-8000-2Q scan: resilvered 472K in 0 days 00:00:02 with 0 errors on Sun Aug 23 16:17:21 2020 config: NAME STATE READ WRITE CKSUM tank DEGRADED 0 0 0 mirror-0 DEGRADED 0 0 0 diskid/DISK-Z4Z46MXG ONLINE 0 0 0 620907994788427922 UNAVAIL 0 0 0 was /dev/diskid/DISK-Z1E4ZCM2 mirror-1 ONLINE 0 0 0 diskid/DISK-Z1E5PFCH ONLINE 0 0 0 diskid/DISK-Z4Z46XQP ONLINE 0 0 0 errors: No known data errors From the above output, we can see that one of the disk in mirro-0 vdev was missing. (In fact, it has been removed prior to the system rebooted. I also inserted a new disk to the system.) ...
I’m still running Fedora 31 on my main desktop though Fedora 32 beta has been out for a while. The only reason that stops me from jumping to F32 now is because ZFS 0.8.3 is not compatible with the kernel 5.6.* on F32. Rumor has it, ZFS 0.8.4 will support kernel 5.6. Tonight, while doing the system update with sudo dnf update -y on F31 desktop, I noticed that the kernel for F31 is now kernel-5.6.6-200.fc31.x86_64. Wait, what? I didn’t interrupt the update process, and let it run till finish. ...
Up until today, I have been running Fedora 29 with the kernel 4.9. The current version of the kernel on Fedora 29 is 5.0. However, I had to stick with the 4.20 version for a very long while due to a thing I did a short while back. So what is that thing? Well, at one point ZFS (stable) no stopped working with the new kernel on Fedora 29. At then, I had a choice to either keep running older version of the kernel or trying out the new version of ZFS (testing). I opped for the second option. When Fedora 29 bumped its kernel to 5.0, unfortunately, the testing ZFS didn’t support this version of the kernel. ...
When Fedora release kernel 4.20.*, the ZFS 0.7.12 could no longer compiled. Accoriding to the ZFS release page at Github zfs-0.7.12 is only compartible iwth kernels 2.6.32 - 4.19. At first I was going to just wait for the 0.8.0 release, and continue to use kernel 4.19. However, Fedora keeps releasing the updates of kernel 4.20. As of this writing, the current version of the kernel on Fedora 29 is 4.20.6-200. At the same time, zfs-0.8.0 is still not yet released. ...