Setting up single VDEV Zpool ?

[VladTepes]

Just a question in regard to when it comes time to set up my system.

I've read various documents and noted that there appears to be only one way to add an additional DISK to a Zpool and that is in a new VDEV.

My board has 6 SATA ports. One will be used for a SSD for the boot drive, leaving me with 5 available SATA ports.

I now have 4 x 3 Tb WD Red HDDs which I will use, and will be using Raidz2 (see I DID read it!) giving me a capacity of 6Tb of storage. This should be more than adequate for now BUT when the time comes to upgrade as far as I can tell the only really option (while retaining redundancy) is to change all of the 3Tb drives to drives of a larger capacity.

From my reading I can't add a disk to an existing VDEV.
Now, I've spent WAY too much money on computers recently BUT would it be a good long term tactic for me to buy a 5th 3Tb drive now so as to have a 5 drive VDEV from the start?

And please confirm my maths - 5 x 3Tb Drives in RaidZ2 ought to give me 9 Tb with 2 drive redundancy.


Suggestions welcome ! Cheers and Thank you.

 

[nojohnny101]

I've read various documents and noted that there appears to be only one way to add an additional DISK to a Zpool and that is in a new VDEV.

Correct.

My board has 6 SATA ports. One will be used for a SSD for the boot drive, leaving me with 5 available SATA ports.

Have you considered using a USB drive instead? Well it is generally a better idea to use a SSD for a boot drive, it is also perfectly acceptable, and probably would make more sense in your case, to use a USB drive because you have limited SATA ports. This would free up an extra SATA port for you.

Your logic is sound with thinking ahead to expanding your storage capacity. For example 's sake, let us say you start off with four disks in a Riadz2 configuration like you stated. Your options for expansion should you need more storage are:
1) move all of your data to an external location (ex. A large external hard drive, another FreeNAS box [replication], etc). Destroy your current 4 disk vdev, add however many disk you want, then create a new vdev with more disks and then load your data back onto the new vdev.
2) leave your existing 4 disk vdev in place and add another vdev. if you go this route, it would be wise to wait until you can purchase maybe three or four discs at once so you can create a new vdev with raidz2. Remember, if any vdev fails in a zpool, you lose the entire zpool and all vdevs it contains.
3) do as you said, and replace all the drives one by one with larger capacity drives. Once you replace all of the drives in the vdev with larger ones, the total capacity will automatically expand.

Now, I've spent WAY too much money on computers recently BUT would it be a good long term tactic for me to buy a 5th 3Tb drive now so as to have a 5 drive VDEV from the start?

I don't really know what type of answer you're looking for from this question. It seems as though you indicated that the current 4 disk raidz2 setup you are planning would provide you with plenty of storage for your needs. So really in my mind, based on the information you provided, there wouldn't be much advantage to buying another disc now and starting off with a 5 disk vdev.

If you think you will outgrow the storage that you have planned now in a short time then it might make sense to buy that fifth disc now. Otherwise save your money or buy more RAM.

 

[VladTepes]

Thanks mate for all your input.

I hadn't considered a USB drive as I had read various threads saying that USB isn't such a great solution and that an SSD is superior. In any event up to 5 3tb drives allowing 9Tb max (as mentioned above) would be more than adequate for ANY foreseeable future in my case. So I'll stick with the SSD.

I previously had a stand-alone NAS with 3 x3tb in Raidz1 equivalent so still allowing 6Tb of data and it was nowhere near full.

I reckon the 32Gb of RAM I have purchased will be enough.... :)

 

[SweetAndLow]

also take into account that once your pool reaches 80% full you should look at adding more disks or removing data. And once you get to 90% full your pool performance will drop and you should never fill your pool to 100%.

 

[BigDave]

And please confirm my maths - 5 x 3Tb Drives in RaidZ2 ought to give me 9 Tb with 2 drive redundancy.

From @Bidule0hm calculator, please click here


If you intend to stay below the 80% capacity recommendation,
your "usable" space would be a fraction over 7 Terabytes or 6.444 Tebibytes

 

[Z300M]

Just a question in regard to when it comes time to set up my system.

I've read various documents and noted that there appears to be only one way to add an additional DISK to a Zpool and that is in a new VDEV.

My board has 6 SATA ports. One will be used for a SSD for the boot drive, leaving me with 5 available SATA ports.

I now have 4 x 3 Tb WD Red HDDs which I will use, and will be using Raidz2 (see I DID read it!) giving me a capacity of 6Tb of storage. This should be more than adequate for now BUT when the time comes to upgrade as far as I can tell the only really option (while retaining redundancy) is to change all of the 3Tb drives to drives of a larger capacity.

From my reading I can't add a disk to an existing VDEV.
Now, I've spent WAY too much money on computers recently BUT would it be a good long term tactic for me to buy a 5th 3Tb drive now so as to have a 5 drive VDEV from the start?

And please confirm my maths - 5 x 3Tb Drives in RaidZ2 ought to give me 9 Tb with 2 drive redundancy.


Suggestions welcome ! Cheers and Thank you.

What about using an add-in SATA card for the SSD boot drive and using the motherboard ports for 6 drives in RaidZ2?

 

[VladTepes]

BigDave - Well, that's a bugger and much lower than I'd anticipated. Worse, is that the 4 drives I currently have will, by that standard, only give me 4.7Tb of storage. (edited due to swear filter interference, which I'd prefer to avoid). "Oh tarnation, how frustrating".
No doubt the % use of the pool is written somewhere but I've obviously missed it.

Looks like I'll have to buy another Red - so have the 5 in total, and hope that lasts me for the foreseeable future. (It should). That's really pushing the budget so a 6th HDD is out of the question at the moment. But thanks Z300M I'll consider that if/when the time comes :)

 

[Z300M]

BigDave - Well, that's a bugger and much lower than I'd anticipated. Worse, is that the 4 drives I currently have will, by that standard, only give me 4.7Tb of storage. (edited due to swear filter interference, which I'd prefer to avoid). "Oh tarnation, how frustrating".
No doubt the % use of the pool is written somewhere but I've obviously missed it.

Looks like I'll have to buy another Red - so have the 5 in total, and hope that lasts me for the foreseeable future. (It should). That's really pushing the budget so a 6th HDD is out of the question at the moment. But thanks Z300M I'll consider that if/when the time comes :)

But you can't add a 6th drive later. If you want six drives in RaidZ2, you have to set it up that way from the start.

 

[VladTepes]

Yes I understand that - just can't happen financially so that's that ! 5 ought to be OK I think.