cmc/cleberg.net
My personal web garden & blog.
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300cdf07720daebd5764f3b0a2dd311e771eb006
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author: Christian Cleberg <hello@cleberg.net> · 2024-02-10T04:14:20Z
content/blog/2024-02-06-zfs.md | 219 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 219 insertions(+) new file mode 100644 @@ -0,0 +1,219 @@ +date = 2024-02-06 +title = "How to Create a ZFS Pool on Ubuntu Linux" +description = "Learn how to create a simple ZFS pool on Ubuntu Linux." + +This post details the process I used to create ZFS pools, datasets, and +snapshots on Ubuntu Server. + +I found the following pages very helpful while going through this process: + +- [Setup a ZFS storage pool](https://ubuntu.com/tutorials/setup-zfs-storage-pool) +- [Kernel/Reference/ZFS](https://wiki.ubuntu.com/Kernel/Reference/ZFS) +- [ZFS for Dummies](https://blog.victormendonca.com/2020/11/03/zfs-for-dummies/) + +## Installation + +To start, I installed the ZFS package with the following command: + +```sh +sudo apt install zfsutils-linux +``` + +Once installed, you can check the version to see if it installed correctly. + +```sh +> zsf --version + +zfs-2.1.5-1ubuntu6~22.04.2 +zfs-kmod-2.1.5-1ubuntu6~22.04.1 +``` + +## ZFS Configuration + +Now that ZFS is installed, we can create and configure the pool. + +You have various options for configuring ZFS pools that all come different pros +and cons. + +- Striped VDEVs (Raid0) +- Mirrored VDEVs (Raid1) +- Striped Mirrored VDEVs (Raid10) +- RAIDz (Raid5) +- RAIDz2 (Raidd6) +- RAIDz3 +- Nested RAIDz (Raid50, Raid60) + +I will be using Raid10 in this guide. However, the majority of the steps are the +same regardless of your chosen pool configuration. + +### Creating the Pool + +To start, let's list the disks available to use. You can use `fdisk` command to +see all available disks. + +```sh +sudo fdisk -l +``` + +Or, if you currently have them mounted, you can use the `df` command to view +your disks. + +```sh +> sudo df -h + +Filesystem Size Used Avail Use% Mounted on +... +/dev/sda1 7.3T 28K 6.9T 1% /mnt/red-01 +/dev/sdb1 7.3T 144G 6.8T 3% /mnt/red-02 +/dev/sdc1 7.3T 5.5T 1.9T 75% /mnt/white-02 +/dev/sdd1 9.1T 8.7T 435G 96% /mnt/white-01 +``` + +If you're going to use mounted disks, make sure to umount them before creating +the pool. + +```sh +sudo umount /dev/sda1 +sudo umount /dev/sdb1 +``` + +Now that I've identified the disks I want to use and have them unmounted, let's +create the pool. For this example, I will call it `tank`. + +```sh +sudo zpool create -f -m /mnt/pool tank mirror /dev/sda /dev/sdb +``` + +See below for the results of the new ZFS pool named `tank`, with a vdev +automatically named `mirror-0`. + +```sh +> zfs list + +NAME USED AVAIL REFER MOUNTPOINT +tank 396K 7.14T 96K /tank +``` + +```sh +> zpool status + + pool: tank + state: ONLINE +config: + + NAME STATE READ WRITE CKSUM + tank ONLINE 0 0 0 + mirror-0 ONLINE 0 0 0 + sda ONLINE 0 0 0 + sdb ONLINE 0 0 0 + +errors: No known data errors +``` + +We can also look at the mounted filesystem to see where the pool is mounted and +some quick stats. + +```sh +> df -h + +Filesystem Size Used Avail Use% Mounted on +... +tank 7.2T 128K 7.2T 1% /tank +``` + +### Expanding the Pool + +If you want to expand this pool, you will need to add a new VDEV to the pool. +Since I am using 2 disks per VDEV, I will need to add a new 2-disk VDEV to the +existing `tank` pool. + +```sh +sudo zpool add tank mirror /dev/sdX /dev/sdY +``` + +I added two 8TB hard drives and this process took around 10 seconds to complete. + +When viewing the pool again, you can see that the pool has now doubled in size. +We have 14.3 TB useable space and the same space used for mirroring. + +```sh +> zfs list + +NAME USED AVAIL REFER MOUNTPOINT +tank 145G 14.3T 104K /tank +tank/cloud 145G 14.3T 145G /tank/cloud +tank/media 96K 14.3T 96K /tank/media +``` + +### Creating Datasets + +According to [ZFS +Terminology](https://docs.oracle.com/cd/E18752_01/html/819-5461/ftyue.html), a +`dataset` can refer to "clones, file systems, snapshots, and volumes. + +For this guide, I will use the `dataset` term to refer to file systems created +under a pool. + +Within my `tank` pool, I am going to create some datasets to help organize my +files. This will give me location to store data rather than simply dumping +everything at the `/tank/` location. + +```sh +sudo zfs create tank/cloud +sudo zfs create tank/media +``` + +Once created, you can see these datasets in the output of your pool list: + +```sh +> zfs list +NAME USED AVAIL REFER MOUNTPOINT +tank 752K 7.14T 104K /tank +tank/cloud 96K 7.14T 96K /tank/cloud +tank/media 96K 7.14T 96K /tank/media +``` + +### Creating Snapshots + +Next, let's create our first snapshot. We can do this by calling the `snapshot` +command and give it an output name. I will be throwing the current date and time +into my example. + +```sh +sudo zfs snapshot tank@$(date '+%Y-%m-%d_%H-%M') +``` + +We can list the snapshots in our pool with the following command: + +```sh +> zfs list -t snapshot +NAME USED AVAIL REFER MOUNTPOINT +tank@2024-02-06_19-41 0B - 104K - +``` + +### Destroy Snapshots + +You can always destroy snapshots that are no longer needed: + +```sh +sudo zfs destroy tank@2024-02-06_19-41 +``` + +Once deleted, they will no longer appear in the list: + +```sh +> zfs list -t snapshot +no datasets available +``` + +## My Thoughts on ZFS So Far + +- I sacrificed 25TB to be able to mirror my data, but I feel more comfortable + with the potential to save my data by quickly replacing a disk if I need to. +- The set-up was surprisingly easy and fast. +- Disk I/O is fast as well. I was worried that the data transfer speeds would be + slower due to the RAID configuration. +- Media streaming and transcoding has seen no noticeable drop in performance. +- My only limitation really is the number of HDD bays in my server HDD cage.