ZFS Basics - Pools and VDEVs - Testing, Configuration, and Expansion

[@sm5172]

Finally a clear and straight to the point explanation that is becoming rarer and rarer on YT these days, thank you.

[@MikeFaucher]

Thank you for that feedback. It is appreciated.

[@Filotto]

I am a beginner and I only found 30 minutes videos on zfs. I really liked how you explained the concepts thanks

[@MikeFaucher]

Glad it was helpful and thanks for the feedback and for watching!

[@ruanth]

Thanks for the detailed beginners tutorial. You answered all the questions I had in my mind without actually addressing them directly as a question but explain how ZFS works. Extremely useful for someone who's building their first NAS in order to move almost 200TB out of cloud storage. Please keep the good content coming

[@MikeFaucher]

Thank you for the great feedback. Appreciate it.

[@Olina_Dey]

Comprehensive and perfectly detailed. The stuff you discussed was so well explained it help me to make inferences about other ZFS features - namely RAID configs. Caching, drive performance, and zfs use cases for future topics.

[@MikeFaucher]

Thank you for the feedback, I appreciated it. I will add these suggestions to my growing list.

[@jayzn1931]

I finally understood expansion in TrueNas now! You cannot extend a vdev (yet) but you can extend a pool by adding vdevs, but if a single vdev fails, the whole pool dies.

[@MikeFaucher]

As long as you only lose one drive the raid will protect the entire pool. Thanks for the feedback.

[@faisalnafees8413]

You got me worried now. So if I got 2 vdevs in a pool and 1st one dies as a whole. I'll lose the data in 2nd vdev also?

[@MikeFaucher]

@@faisalnafees8413 Yes, like any raid config, assuming you have one drive of redundancy, you have to make sure you don't lose more than one drive. You need to make sure you have a backup. I just lost a raid array a couple of weeks ago so I share your concern. Fortunately it was a backup unit.

[@decmade]

best explanation I have seen online

[@MikeFaucher]

Wow, thank for the feedback. Appreciate it.

[@jeffreyrh]

You are always learning. I just learned that on UNRAID zfs, the shares are actually datasets. So if you have 2 shares on the same disk, and try to move large folders from one share to the other, expecting them to move instantly since they are on the same disk, you would be wrong. It has to do a full copy and delete because each dataset is it's own file system. I figured this out after numerous tries :)

[@MikeFaucher]

Thanks for the feedback. To add to some of the confusion, everyone is implementing ZFS a bit differently.

[@mahmoudelgendy5348]

Just helpful and straight to the point. Thnx Mike.

[@MikeFaucher]

Thank you! Appreciate the feedback.

[@kanishkaperera8155]

The best explanation ever.

[@MikeFaucher]

Thank you for the feedback!

[@kelvindiaz8409]

You explained this so well! Thanks!

[@MikeFaucher]

Thank you for the feedback. It’s appreciated.

[@aliaghil1]

What a great video! Thank you for sharing it with us.

[@MikeFaucher]

Glad you found it helpful and and thanks for the feedback.

[@EricCheng-v7b]

Thank You , this is a great intro to get started

[@MikeFaucher]

Great to hear. Thank you for the feedback.

[@wyattarich]

Great video, hopefully you can cover mirrored array performance increases and caching next.

[@MikeFaucher]

Thanks for the feedback and I will add it to my list.

[@Jazzynupe1911]

Side note, there is a new feature coming soon that will allow you to add a single drive to a VDev as well. Not sure if it is released yet but it was discussed in another video.

[@MikeFaucher]

Yes, I heard about this. QNAP's ZFS based Hero has been doing this since the last release. I look forward to the TrueNAS Release.

[@Karimpje]

Hey thanks for your explanation. I have a Truenas running with a Zpool with one VDEV of 4 disks of each 4TB. I have 10TB usable storage space, because I use RAIDZ1. The Zpool is 96% full. Now I have two 4TB spare disks and I want to expand my Zpool with these disks. Should I add a new VDEV with only the two disks in a mirrored mode or should I buy myself a new 4TB disk and create a new VDEV with three 4TB disks?

[@MikeFaucher]

Thanks for the feedback. Personally I would buy two more as it will be more efficient.

[@Karimpje]

@@MikeFaucher Thanks, I'm just not sure if my NAS has much more room. I know that the two spare disks will fit, as I bought two hot swappable drive bays, I could add one more I think but another I don't know. It is not that I don't want to, it's more the limitations of the hardware I am using as a NAS (Dell Precision T7500 with 96 GB RAM and 2 Xeon X5670 CPU's)

[@outcast6187]

What I want is to know how to expand my currently used single 8TB drive on TrueNAS to a 3x 8TB drive setup with a RAIDZ1 configuration.

[@MikeFaucher]

You have to move data off the single drive and create a 3x8 VDEV, then copy the data back on to it.

[@zyghom]

actually you did not say much about zfs config - rather about truenas when you said at the beginning: "I wanted to learn ZFS" I thought you would show the commands (zfs, zpool etc) to do it from the terminal ;-)

[@MikeFaucher]

Thanks for the feedback. I was more focused on pools and vdev. Never been a fan of the command line but good point.

[@JourneywithBrandon]

Knowing I have six drives available, would I rather have a single VDEV in Z2, or two VDEV in Z1? I'm using spinning rust from ebay, and the resilver process would freak me out. This is a great video though, I'm just hung up on this decision.

[@MikeFaucher]

So I have always recommended Z1 with a back up for home use for reasons of storage efficiency. I have a video on the resilvering process (kzbin.info/www/bejne/oYLLf6Kuhp5laJo) and it is very easy. I currently have 6 NAS units, one TrueNAS, and one UNRAID and all use a Raid 5 0r Z1 configuration. I keep a spare drive around and immediately replace it. Every unit I have has has a bad drive replaced at one point. Just to be on the safe side, I also have two backups. If you don't mind losing the storage, and want to be double sure, go with Z2 but you still need a backup. For me I am sticking with Z1 (RAID 5). Hope that helps.

[@alonzosmith6189]

Hello, great video. I researching building a TrueNAS server for home with 8 drives. I was thinking creating 1 pool and 1 vdev then creating datasets for my family members and Plex

[@MikeFaucher]

Sounds like a solid plan. Let me know how it works out.

[@OT-tn7ci]

Hey thanks man, so it looks like, unless I can add more drives to vdevs later on, especially parity drives. It will be kinda hard to upgrade storage in this config.. Because of the stripping behavior. I want to first start out all my vdevs without any parity drive as I upgrade slowly. And then add in the parity drives later on, since I don't want to create new vdevs, creating new vdevs sound like a bad idea, because of the stripping behavior.

[@MikeFaucher]

@@OT-tn7ci that feature is coming soon.

[@AndrewAllmer]

Is it possible to go from RAID6 to RAID60 with zfs? I’m planning to start a pool with a 4 drive vdev in RAIDz2, then add another 4 drive vdev in RAIDz2 later to add capacity. Is that possible?

[@MikeFaucher]

Yes if you are adding a whole vdev and not just adding drives. Currently, there is not way to migrate raid levels or expand a pool.

[@AndrewAllmer]

​@@MikeFaucher Awesome thank you!

[@scristaldi]

How about for starters ... 4 1tb drives... create the different combo's with data and parity...and explain the what's and why's .... I am using ubuntu ... then create a zfs system pool for samba so all pc with linux and windows can use samba for backup/storage et al... hows that for a start...

[@MikeFaucher]

Thanks for the input. Interesting use case.

[@sandrovieirafotografo]

Show, muito esclarecedor, Obrigado.

[@MikeFaucher]

Gracias por los comentarios.

[@B_r_u_c_e]

Thank you.

[@MikeFaucher]

You are welcome.

[@AinzOoalG0wn]

oo i see uve hopped on the truenas bandwagon. yes it has zfs so thats a good place to try that out :} when ur going from qnap to truenas, u'll notice the UI setup process has some steps to do. Part of the setup, you will need another account other than the default root. Root only lets u access the UI, but it won't let u access the share (as intended for security). So u have to create an account for that, and bind it to the share u create. u also have to go to services and enable smb. Test on your desktop whether you can access the share on smb to confirm it works. There are probly other steps, but these are the main ones to do. Are u using truenas scale or core? Not sure whats the latest news, but last time scale (linux) was still considered beta. core is stable (bsd).

[@MikeFaucher]

Thanks for your input. I have been using it for a bit and have a couple of SMB set up. Currently due to the speed I am using it for a video server where I edit my videos. Thanks for the input as always.

[@JohnUllrey]

Thanks, this was supper helpful. I'm planning out my first TrueNAS build. (Like'd & Sub'd)

[@MikeFaucher]

Glad it helped and thanks for the feedback. Good luck with your build.

[@djmulder]

Thanks for the explanation... tho I'm still not too happy with how it all works (not you but zfs in general) I come from a drobo, which ofc has it's own issues and isn't perfect. The thing I loved is that you could just plop out a disk, put in a new/bigger one and it will happily rattle along and you have more space. This is completely what I'm missing with ZFS.. I have to have equal drive sizes, need to have a fixed vdev.. or chose to lose usable space.. etc etc.. I could live with multiple vdevs if I could just expand my vdev that has bigger disks and eventually remove my vdev which has smaller (so shrink until 0).. but yeh that's not possible. So I'm thinking: I could make vdevs of 3 disks, then when I upgrade I only need to get 3 disks... which works.. but then I have the issue that I lose 1 parity disk per vdev (so a lot of usable space loss) and yeh still need to upgrade 3 disks at a time. And on top of that I don't really have full redundancy.. as yeh if 2 disks die in 1 vdev I lose my entire pool.. even if I have say 4 vdevs, so 4 parity disks, yet still effectively 1-4 disk loss.

[@MikeFaucher]

I feel you pain. You could run UNRAID in its more Drobo like operation if you want to use random disks and don't mind loosing a bit performance. I use both and only use ZFS TrueNAS which has only purpose and my all flash QNAP NAS which uses ZFS but allows me to add a drive to the pool which is feautre I really like. For media and backup, UNRAID is not a fast but very scalable with different size drives.

[@djmulder]

@@MikeFaucher yeah I have unraid now, but I just don't like the performance. I've been investigating zfs because of that but I just can't make the step because of the issues

[@hadeseye2297]

Thanks.

[@MikeFaucher]

Thanks for the feedback!

[@scristaldi]

There is a lot more to zfs than this one video... why don't you do more....

[@MikeFaucher]

I agree there is much more. Any suggestions on what additional topics you would like to see.

[@coletraintechgames2932]

Metadata and dedupe vdev

[@MikeFaucher]

Thanks.

[@callisoncaffrey]

I see Windows, I leave.

[@MikeFaucher]

Thanks for your input.

[@callisoncaffrey]

@@MikeFaucher That's funny. I do that too! Made me smile, gets a like.

[@camixxx]

Are you doing the reading and writing simultaneously? Wouldn't saturation be closer to 1250 MB/sec for a 10 Gbit connection?

[@MikeFaucher]

I have yet to see anything that high but you are right in theory. In these test, limitations were from the SSD drives and controllers as they are SATA. It would take a pretty large pool or nVME to max out the 10G connection. That said, without playing with jumbo frames and relieving all the other bottlenecks. 900-1000 is a bit more real world on a 10G network, at least from what I have seen. Good observation and thanks for the feedback.

[@lyndajones1133]

6:24 what did you do to get to there? like so a file on my desktop. share it to nas pool....watch its speed. gotit. but howto. there inlines why im here actually. jah know what im sayin.

[@MikeFaucher]

Thanks for the question, but I am not sure I completely understand. The section you are referring to only shows the capacity and then a regular file copy test (read and write) of a single VDEV. Can you clarify? Thanks