Question about buying HDDs

[Carlos D]

I'm building my first nas and I bought everything except the hdds. Will be going for wd reds (regular, not pro) but I was wondering if there are any specific rules to follow when buying hdds.

I was originally planing on mixing the size of hdds i.e 4tb + 3tb + 6tb.

Is there something wrong with that?
Is it better to have all same sizes?
Anything else to know before buying hdds?

I heard that wd red 3tb had some issues.

Thanks!

 

[Stux]

Well, mixing hd sizes will result in unused hd capacity. Assuming you want redundancy.

Suggest looking into the basics of ZFS and hd configurations *before* purchasing HDs, otherwise you may make an expensive mistake.

 

[pschatz100]

I'm building my first nas and I bought everything except the hdds. Will be going for wd reds (regular, not pro) but I was wondering if there are any specific rules to follow when buying hdds.

I was originally planing on mixing the size of hdds i.e 4tb + 3tb + 6tb.

Is there something wrong with that?
Is it better to have all same sizes?
Anything else to know before buying hdds?

I heard that wd red 3tb had some issues.

Thanks!

Why are you planning to mix drive sizes? What, exactly, do you wish to accomplish?

Backblaze and Google have published reports on the life of their drives, and it appears that 3Tb drives seem to have more issues that 2Tb or 4Tb drives. There is not enough experience with larger drives to know how they will perform.

Personally, I would purchase 4Tb drives.

 

[Chris Moore]

I'm building my first nas and I bought everything except the hdds.

What did you already buy and how much storage did you have in mind being able to use?
There are many factors that go into selecting storage.
If you will share with us how you plan to use it, we may be able to provide better suggestions.

 

[Carlos D]

Why are you planning to mix drive sizes? What, exactly, do you wish to accomplish?

Backblaze and Google have published reports on the life of their drives, and it appears that 3Tb drives seem to have more issues that 2Tb or 4Tb drives. There is not enough experience with larger drives to know how they will perform.

Personally, I would purchase 4Tb drives.

Found a good wd red 6tb for sale and was thinking of getting it but I guess I'll just go for with 4tb instead, thanks!

 

[Carlos D]

What did you already buy and how much storage did you have in mind being able to use?
There are many factors that go into selecting storage.
If you will share with us how you plan to use it, we may be able to provide better suggestions.

ASRock C2550D4I
Seasonic SS-350GT 350W
16gb (2 x 8) ecc ram
I'm planning to have somewhere around 10tb of usable storage.

 

[Chris Moore]

If you only want 10TB usable you could get there with only 5 x 4TB drives in a RAID-Z2 configuration, but I would suggest getting six drives to give you a little growing room as you will likely have the system for 3 to 5 years. I also suggest the Seagate drives, I use all Seagate in my systems and have had good results with them and they are a little less expensive than the Western Digital drives.
With FreeNAS, because it uses ZFS for the file system, it is best to have all your drives the same size, but they do not need to be from the same vendor or even the same model.

 

[Carlos D]

Thanks for all the info, I decided to buy 6tb wd drives because my psu. According to the recommendations on the docs, it's good for 3 to 4 drives.

Now my other question would be, can I start with one 6tb drive just to get things going and then add another 6tb? Is it better to have both drives to start?

I understand that if I only have one drive to start, it won't be mirroring the data over to the other drive and that's fine because I will be adding another 6tb afterwards to enable that and possibly a third one to get more usable space and eventually get to ~10tb of usable space. So if I only use one drive to start, does that mean that it will default to raid 0? When I decide to add the second 6tb drive it will automatically switch to raid 1?

 

[danb35]

When I decide to add the second 6tb drive it will automatically switch to raid 1?

No. You can make that happen, but it's somewhat tricky and involves work at the CLI. You need to read up a bit on ZFS. Start here.

 

[Carlos D]

No. You can make that happen, but it's somewhat tricky and involves work at the CLI. You need to read up a bit on ZFS. Start here.

ok, thanks for the link. I will definitely have a look, so basically if my plan is to raid1 it's easier to start with 2 drives? I don't mind working with the CLI, since this is my first build I want to get things going first (simple setup) and then play around and learn more of the advanced stuff.

 

[Chris Moore]

I understand that if I only have one drive to start, it won't be mirroring the data over to the other drive and that's fine because I will be adding another 6tb afterwards to enable that and possibly a third one to get more usable space and eventually get to ~10tb of usable space. So if I only use one drive to start, does that mean that it will default to raid 0? When I decide to add the second 6tb drive it will automatically switch to raid 1?

From what you have said so far, you want to be able to use FreeNAS in a less standard way. Some of what you want can be done, but not all.
If you want to be able to do it from the Graphical interface, you will need to add disks in pairs. You can establish the storage with a mirrored pair and grow the storage with another mirrored pair later. FreeNAS does not work like Synology where you just add a single drive when you feel like you want more storage and it just reshuffles the data to accommodate you. It just doesn't work that way.

 

[Carlos D]

From what you have said so far, you want to be able to use FreeNAS in a less standard way. Some of what you want can be done, but not all.
If you want to be able to do it from the Graphical interface, you will need to add disks in pairs. You can establish the storage with a mirrored pair and grow the storage with another mirrored pair later. FreeNAS does not work like Synology where you just add a single drive when you feel like you want more storage and it just reshuffles the data to accommodate you. It just doesn't work that way.

Ok, thanks again for the info!

 

[Inxsible]

I'd suggest you simply keep using mirrored pairs and keep increasing the number of vdevs as and when you need more storage. As long as the disks are in separate vdevs, you can even use different sizes without losing disk space. You get the same redundancy as the RAIDZ1 (that you were originally considering).

I currently use such a configuration. 2x6TB Seagate Ironwolf + 2x500GB Seagate Constellation + 2x500GB Seagate Constellation. Gives me 7TB of space with 5.3TB usable space. Eventually I will upgrade the 500GBs with bigger drives, but I am not constrained with buying the same size. If 8TB happens to be cheaper at the time, I can go for that or any other size.