Risk Assessment approaching 24 drives and then....?

[deaerator]

Exactly what the the title states.  I'm approaching 24 drive limit on my Norco 2442 case.  I'm starting to get a bit nervous when I only have can have 2 Parity drive limit, or two hard drive Failure at once. How many hard drives should I be adding safely to this 2 drive parity limit, the risk factors.  Will Disk Shelves work with unraid? I was thinking picking up a couple DS4243 and moving all my storage on to that and have a separate pc do to all the hard work. Or is time to find a new storage OS solution?

[trurl]

Increase capacity by replacing drives with larger drives.

[testdasi]

Replace your drives with higher capacity and reduce your number of drives.

 

One of the main advantage of Unraid is the ability to use mixed-size drives. That allows easy consolidation of storage over time i.e. you don't have to replace all your drives at once.

 

And due to how HDD tends to fail (in a probabilistic fashion), having fewer drives reduces your risk of having more failed drives simultaneously than parity.

[BRiT]

Time to upgrade the size of your drives and retire the most vulnerable drives going by SMART report numbers.

 

About every 4 years I double the size of my drives while cutting the number of them in half, going off memory my move including data and parity drive was 8 2TB to 5 4TB to 4 8TB but with a ton of free space on Drive 3 (85% free).

 

Drives 1,2,3 and Drive 7 became Drive 1 since they weren't entirely full but I had them separated for potential growth and now they have plenty of room for growth (Music, Pictures, Projects, other server backups, TV shows and UFC). Drives 4,5,6 became Drives 2,3 with 50% space still free on Drive 3 (Movies).

[Michael_P]

Unraid has a 30 drive limit for the array, so there's that. As for your risk tolerance, well, you need backups for anything you can't afford to lose. Every storage OS is similar in that regard. Parity, RAID, whatever, it's not a backup. If you can't afford to lose it, you can't afford not to back it up.

[sota]

@Michael_P aye... been working with a vendor to try and supply me 4TB (minimum) sized used disks at $8/TB.  Just waiting to see how many disks they want me to buy at that price.

[trurl]

33 minutes ago, sota said:

used disks at $8/TB

Will they supply SMART reports before purchase?

[sota]

Good question.  I'm going to guess no, given the low price i'm looking at.

Since my goal is to keep costs at $10/TB or lower, as long as more than 8 of 10 disks I buy has no major issues, I'd call it a win.

 

eta:

one of my intentions is to somehow do a checksum setup for the data on the backup disks, to a-periodically test their contents for validity.

still working on that aspect of this project.

these are going to be load and forget storage for the most part.  backup to the mega movie and TV collection I have here, and possibly other archival needs. I would easily expect to not touch these disks for >2 years, or even ever if i'm being truly lazy.

Edited December 11, 2019 by sota

[BRiT]

There are many existing plugins that do file content checksum, no need for you to reinvent that.

[sota]

I figured/hoped.  It's on the list of things to investigate.

[deaerator]

6 hours ago, Michael_P said:

Unraid has a 30 drive limit for the array, so there's that. As for your risk tolerance, well, you need backups for anything you can't afford to lose. Every storage OS is similar in that regard. Parity, RAID, whatever, it's not a backup. If you can't afford to lose it, you can't afford not to back it up.

That is good to know, my current unraid machine is all 8TB hard drives. 

[sota]

I've started probing vendors for 4TB or larger disks in the sub $10/TB after taxes range.  I guess if anyone is interested in my findings let me know?  I'll be negotiating price, pre delivery testing, and warranty policies.

[sota]

Finally did a thing, and just ordered 20x 4TB SAS disks for $457.46 shipped.

It'll be fun testing all of them when they show up.

Hoping I can run an unRAID install on a different USB stick (so as not to mess up my current config, and without yanking my production unRAID stick out from inside the case) and run pre-clear on disks 10 or so at a time.