BUILD Build Help - What can I do with my existing drives?

[Soultazer]

Hi everyone!
I'm very new to FreeNas and I've been reading through the forums to try to gain a good understanding of how to configure my new system.

I currently have an existing server with the following hard drive configuration:

• 1 TB Western Digital Green (WDC WD10EARS)
• + (another) 1 TB Western Digital Green (WDC WD10EARS)
• + 2 TB Western Digital Green (WDC WD20EARX)
• = 4 TB of space. 3.5TB is currently in use.

When I first built my server many years ago, I didn't really know how to configure the system properly and so I just tacked on the hard drives using JBOD and Windows 7.

I am in the process of researching to build a brand new server (I have read through the Hardware Recommendations thread that was posted by CyberJock) and will be attempting to use as much of the recommended hardware as possible.

I was also looking through the PDF/PPT on the basics of VDEV configurations and I was wondering if you guys have a good idea on how I can configure my hard disks listed above.

I understand that I will need to buy new disks as I am adding redundancy. I will also like to eventually expand the capacity so I will need to configure my VDEV so it is setup properly.

Any ideas?

Thanks everyone! :)

 

[Soultazer]

Anyone out there?

 

[HoneyBadger]

Yes.

You mentioned you're going through the recommendations thread; can you post some of what you've come up with? The problem with any kind of static reference point like a thread/wiki/PDF is that it risks becoming a little outdated over time as we learn new things, so let's see what you've sorted out.

Also let us know what you want to use this system for; we'll suggest something completely different depending on if you want to build a slow but stable place to warehouse family photos vs a place to host storage for a home-lab ESXi cluster.

Regarding your vdevs/drives, you'll definitely want to be using wdidle or similar to stop those Green drives from constantly parking themselves. Generally speaking your choices are "mirror" or "RAIDZ2" for vdevs; for the former obviously you start with a pair of drives and add additional mirror vdevs as you grow, but a RAIDZ2 you usually get the best value from a 6-drive (4 data, 2 parity) start, and then expand 6 drives at a time.

 

[Soultazer]

Hooray! Thanks HoneyBadger
Ok so the specific thread that I was reading through was this one for hardware: https://forums.freenas.org/index.php?threads/hardware-recommendations-read-this-first.23069/
And this one for ZFS storage explanations: https://forums.freenas.org/index.ph...ning-vdev-zpool-zil-and-l2arc-for-noobs.7775/

My plan is to essentially have a location to download (Sickbeard/SabNZB), stream (Plex/XBMC), and store vidoes/movies (Zpools) within my own LAN network.
I currently have no redundancy with how it is configured now and I'm worried that if one of the hard drives go, I will lose everything. Since it is JBOD, that is what would happen.

Thanks for the info about wdidle :). I'll make sure to incorporate that into my configuration.

I have read and understood that RAIDZ2 is the way to go as RAIDZ1 is slowly becoming outdated. As per your recommendation, I will build to 6 drives for 2 drive tolerance

Here is what I understand so far (please correct me if I'm wrong ;)):

• RAIDZ2 is similar to RAID6 in which I will need 4 data drives and 2 parity drives (as you mentioned).
• Once a VDEV is created, you cannot add to it. Once a VDEV is added to a ZPOOL, you can't remove it. <- This scares me as I'm not 100% sure how to configure it right the first time.
• A VDEV can be a single disk or multiple disks
• A VDEV can be mirrored or striped together using ZPOOLs
• In order for me to expand my maximum capacity, one way is to completely swap out all 6 drives at one time and FreeNAS will take care of autoexpansion (provided that it is turned on). Alternatively, add VDEVs

So, with these rules in mind. One possible configuration with my current drives are:
VDEV1: 1 TB WD Green + 1 TB WD Green (striped together)
VDEV2: 2TB WD Green
ZPOOL: Mirror VDEV1 with VDEV2 -> 2TB usable and 2TB backup
I guess in this case, if one of the 1TB drives die, I still have VDEV 2 to save me? Or reverse it so the striped set (1+1) is backing up the 2TB?
This is only considering my current drives...so now if I wanted to expand this (ie. add a drive/replace a drive) it will get a lot more complicated.

Should I just dump these drives and consider a whole new set of disks from the beginning? (ex. 6 x 6TB WD RED :p)

Thanks for your help!

 

[HoneyBadger]

Looks like you've done your homework. A little bit of minor corrections though.

• RAIDZ2 is similar to RAID6 in which I will need 4 data drives and 2 parity drives (as you mentioned).
  Bingo. There's some other advantages to Z2 over 6, but largely similar.
• Once a VDEV is created, you cannot add to it. Once a VDEV is added to a ZPOOL, you can't remove it. <- This scares me as I'm not 100% sure how to configure it right the first time.
  Well, that's why you're here, right?
• A VDEV can be a single disk or multiple disks
  Correct.
• A VDEV can be mirrored or striped together using ZPOOLs
  Not quite. A zpool is a collection of vdevs, and they ONLY add by striping together. Hence why you can't ever remove a vdev from a zpool without destroying it completely, and why it's so important to nail the layout when building them.
• In order for me to expand my maximum capacity, one way is to completely swap out all 6 drives at one time and FreeNAS will take care of autoexpansion (provided that it is turned on). Alternatively, add VDEVs
  You'd have to swap each of those six drives one at a time, letting the zpool rebuild completely each time, and then expanding once all six are done. Adding a second vdev (of six drives in RAIDZ2) is the far, FAR better solution.

So, with these rules in mind. One possible configuration with my current drives are:
VDEV1: 1 TB WD Green + 1 TB WD Green (striped together)
VDEV2: 2TB WD Green
ZPOOL: Mirror VDEV1 with VDEV2 -> 2TB usable and 2TB backup
I guess in this case, if one of the 1TB drives die, I still have VDEV 2 to save me? Or reverse it so the striped set (1+1) is backing up the 2TB?
This is only considering my current drives...so now if I wanted to expand this (ie. add a drive/replace a drive) it will get a lot more complicated.

Should I just dump these drives and consider a whole new set of disks from the beginning? (ex. 6 x 6TB WD RED :p)

Thanks for your help!

Afraid not. As mentioned above, vdevs only stripe in a zpool, so that pool would have zero redundancy. Not the way you want to roll.

I'd go with a new set of drives - maybe not 6TB each, because that could get spendy, but 2TB/3TB REDs are certainly getting to a sweet spot pricewise, and six of them in a RAIDZ2 would give you either 8TB or 12TB of usable space. You could get four additional 1TB drives (Greens, even, but mind that wdidle/head-parking issue) and make a 6x1TB RAIDZ2 (4TB usable) as well for a budget-minded option.

And once you do create the pool, you can easily dump a screenshot/output of "zpool status" and we can tell you if you did it correctly before you start filling it with data.

 

[Soultazer]

Wow this is super fantastic. Thank you for your help and feedback! I am learning a lot :D

Ok! That makes sense. So to confirm my understanding...essentially, the ENTIRE RAIDZ2 is a VDEV? So say I somehow run out of space with 8TB/12TB, then I add in another set of 6 disks configured in RAIDZ2 with a VDEV and then stripe them together with a ZPOOL to get 16TB/24TB. Does that sound about right?

I still do not have any of the hardware (yet) so it will take me a bit of time before I will be able to do 'zpool status' but I'm very glad to know that this is plausible and an ideal setup.

Thanks again for your help HoneyBadger!

 

[HoneyBadger]

Ok! That makes sense. So to confirm my understanding...essentially, the ENTIRE RAIDZ2 is a VDEV? So say I somehow run out of space with 8TB/12TB, then I add in another set of 6 disks configured in RAIDZ2 with a VDEV and then stripe them together with a ZPOOL to get 16TB/24TB. Does that sound about right?

Terminology's a little off but you've got the idea.

A zpool is a collection of one or more vdevs. A vdev is a group of drives.

zpools are always striped across all vdevs they contain, regardless of how the vdevs themselves are set up. Losing a vdev is always fatal to the zpool.

vdevs can be set up as mirrors, RAIDZ, or even single devices. They have different levels of tolerance for drive failure.

The danger comes when you expand - when you expand from 6 drives to 12, you have to remember to create that second vdev as RAIDZ2 as well. Can't remember what slide that's on in cyberjock's presentation but he goes over that.

 

[cyberjock]

Wow this is super fantastic. Thank you for your help and feedback! I am learning a lot :D

Ok! That makes sense. So to confirm my understanding...essentially, the ENTIRE RAIDZ2 is a VDEV? So say I somehow run out of space with 8TB/12TB, then I add in another set of 6 disks configured in RAIDZ2 with a VDEV and then stripe them together with a ZPOOL to get 16TB/24TB. Does that sound about right?

I still do not have any of the hardware (yet) so it will take me a bit of time before I will be able to do 'zpool status' but I'm very glad to know that this is plausible and an ideal setup.

Thanks again for your help HoneyBadger!

Yep.. just like the picture I have in my noobie guide...

 

[Soultazer]

Fantastic guys!
Thanks so much for your help. I'm excited to start building this machine soon.

Also thanks cyberjock for your wonderful guide. Really helped clarify everything :)