Recommendations for a "typical" home user?

[ChiknNutz]

Yeah, I know this can vary quite a bit, but I imagine that there is a trend towards which RAID type, disk count and disk size many people land on. In my situation, my current plan is to use a qty of 4 - 3TB drives in a RAIDZ2 array, which will yield about 5.5TB of usable space. Since I have discovered that you cannot add drives to a volume (any chance that will change in the future?), it is clear that the initial setup considerations need to be taken seriously.

My current usage plan is for 2 or 3 computer backups (plan is to use Crashplan), file sharing and storage (photos, videos, music, documents, software executables, etc.) and to use Plex (which I currently don't use, but like what I see so far). I am migrating from a Windows Home Server and had about 1.5 TB of storage available and used about 75% of that for actual data (the computer backups took up the most).

Important to me is data "safety" hence my plan to use RAIDZ2 for data redundancy. However, I am concerned that I might end up being disappointed in the long run by not going to 6 disks instead of 4. Also by using 6, I see that 4 will be used for storage and 2 will still be used for parity (versus 2 and 2 if I use 4 disks), so you see less storage "loss"...right? Still, 5.5TB of storage is already like 4X more than I have now. I am not naive in thinking the amount of data won't grow appreciably over time as file sizes continually grow all the time.

I guess I would like to hear from others that have blazed this path ahead of me and hear of lessons learned in this regard.

 

[joeschmuck]

Since I have discovered that you cannot add drives to a volume (any chance that will change in the future?)

Nope, I do not foresee that every changing. You can upgrade the size of the drives to increase capacity though without data loss.

As for how many drives... Well at least you are planning ahead. I'd like to keep this simple since we are talking about a home system and not some high end office equipment. First you have chosen a RAIDZ2 system which is the first step in the right direction so you are good there. Second you know your required storage capacity. When determining your storage capacity, ensure you are planning for at least 3 years into the future because you do not want to run out of space before your hard drive may start failing. In 3 years most drive warranties expire (WD Red for example) and you could begin upgrading individual drives to a higher capacity if your storage needs have increased. You are after all starting out with a modest 3TB drive size and we know that 6TB drives currently exist.

There are some benefits with using six drives over four drives but this is more with resilvering speed of a single drive. If you used six 2TB drives (approx 7.2TB storage) it would take less time to resilver a drive assuming the pool has the same amount of raw data stored on it. To some people this makes a difference, especially if they have a RAIDZ1 setup. From my own personal experience, I run a six 2TB drive RAIDZ2 setup and when my drives start failing, I'm planning to replace it with four 3TB or 4TB drives. This will actually cost me less money when replacing my drives. I do have a method to my madness.

Something else for you to consider is the case your NAS will fit into and cooling for the hard drives. A cool hard drive lasts longer. Notice I said cool, not cold or hot. 4 hard drives in a confined space is cooler than 6 hard drives in the same space.

I hope I answered your questions.

EDIT: Any really important information should always be backed up to a safe place, a single NAS is not a safe place. I place a copy of all my photos and financial information in DVD's periodically.

 

[Robert Trevellyan]

I'm satisfied with 4 drives. One benefit of fewer drives is that expanding capacity by replacing all drives with larger drives isn't so daunting. My plan is to replace any failed 2TB drive with a 4TB drive, assuming my storage needs don't outgrow my current storage before that happens.

 

[ChiknNutz]

I got turned onto the M-Discs while doing some research. Can anyone attest to the longevity of those? At first blush those seem like a good way to go for permanent backups.

 

[joeschmuck]

I think it would come down to cost. I don't need to retain a backup for 1000 years. If I worked in the Smithsonian, I might want to put all my digital content on something like that.

 

[Robert Trevellyan]

Can anyone attest to the longevity of those?

Looks like cool, new technology, so probably not.

 

[anodos]

I got turned onto the M-Discs while doing some research. Can anyone attest to the longevity of those? At first blush those seem like a good way to go for permanent backups.

The drive is fairly cheap. You're looking at $184/TB for disks or $1,140 for 6TB. Write speed will probably be slow. I've had regular data DVDs last 10 years.

If I were needing to archive something super long-term, I'd look into an LTO-6 drive and using LTFS. It'd be easier to use and is more proven technology. Unfortunately, the upfront cost of a drive is very expensive. Tapes are relatively inexpensive. You can find them for as little as $30 each, and they store 2.5 TB uncompressed or 6.0TB compressed, IIRC.

 

[ChiknNutz]

What I would be archiving, for the most part, would be photos and such which currently only accounts for about 25GB of data, so a couple of those M-Discs would be fine for what I anticipate. Since the older photos would not be changing over time, I would only be archiving new stuff. So for this application, they seem like a good option, albeit expensive per unit of storage as compared to some other options.

 

[joeschmuck]

I only use single layer DVD-R media and it works great. As you say, you only need to write new changes however I typically write a full new set of discs each time. It's not that many discs and the cost is cheap. My 5 DVD's are cheaper than the single BluRay disc and I know I'll have no problems reading them on any DVD drive. I'm not sure if you can read an M-Disc on a non-M-Disc drive. If these are a fad and they fade away (like the ZIP disc), you could be stuck with expensive data retrieval costs.

 

[ChiknNutz]

I'm satisfied with 4 drives. One benefit of fewer drives is that expanding capacity by replacing all drives with larger drives isn't so daunting. My plan is to replace any failed 2TB drive with a 4TB drive, assuming my storage needs don't outgrow my current storage before that happens.

What types of things do you use your NAS for? Do you use it to store ripped movies?

 

[Arwen]

...
I'm not sure if you can read an M-Disc on a non-M-Disc drive. If these are a fad and they fade away (like the ZIP disc), you could be stuck with expensive data retrieval costs.

The Blu-ray version of the M-Discs can be written, (and read of course), with a stock Blu-ray writer.
DVD M-Discs can be read on stock DVD drives.

Both M-Disc, DVD and Blu-ray, have the added advantage of tougher disc media than older DVDs.
(Some newer DVDs use hard coatings and other techniques from Blu-ray.)

 

[Robert Trevellyan]

What types of things do you use your NAS for? Do you use it to store ripped movies?

I have a few ripped DVDs stored on it, mostly raw DVD images, but a few transcoded to H.264. There are even a few VHS movies.

It's primary purpose is to serve as a backup destination for 3 Macs and one PC, and to run a few Ubuntu Server VMs via the VirtualBox Jail.