New unRAID server, different size disks question

[KptnKMan]

Hi, I have finished building my new unRAID server and I'm setting up my array at the moment.

 

I understand that I can use different size disks in unRAID and it doesnt care, but I am wondering what the best disk configuration for me is?

I'm planning to consolidate as many disks into my new server as possible, ideally in a single array.

I'd like to maximise the usage of my storage server if possible.

 

I have:

2x 250GB nvme (new, for cache)

4x 6TB disks (new)

5x 3TB disks (from my old server)

1x 2TB (old server)

2x 1.5TB (old server)

2x 1TB (old server)

 

So I have a few questions:

- Should I setup the array with 2 parity drives or 1?

- Should I use 2x 6TB drives for parity?

- Can I remove drives later, when I want to replace with higher capacity?

- Should I only create a single array from the largest drives? Will this matter?

 

I'm a new user to unRAID so I'm not sure here.

[phbigred]

https://wiki.unraid.net/Shrink_array

You can shrink your array, I've done it as few times. If you are looking to reduce the count of disks go with a single parity. Remember it has to be = or greater than the largest drive. Word to the wise... If you are thinking of encrypting later on, you may want to do it from the beginning as in-place encryption isn't available yet. Also confirm your nvme drives aren't using a Marvell controller, known issue with Linux. 

[trurl]

I don't think shrinking the array is really what you were thinking about with this question:

6 hours ago, KptnKMan said:

Can I remove drives later, when I want to replace with higher capacity?

Replacing a disk with a larger disk is simply a matter of assigning the larger disk to the slot that you want to replace and let Unraid rebuild to the larger disk from the parity calculation.

 

How much capacity do you really need? I would just leave out the smaller disks unless you really need the space now. I always recommend fewer larger disks vs more smaller disks. Larger disks are more cost effective, larger disks have some performance advantages, and fewer disks take fewer connections and have fewer opportunities for problems. And you can always add the small disks later if you need to. Don't install more disks than you currently need.

 

You mention using disks from an old server. Unraid must format any disk it will use in the parity array or cache pool, so if those disks have any data you want to keep you must copy it somewhere if you want to reuse those disks.

 

Also, it is important that you only use reliable disks in the array. Parity by itself doesn't allow you to recover any data. Parity plus ALL the other disks are required to calculate the data for a missing disk. Every bit of every disk must be reliably read to reliably reconstruct a failed disk.

[KptnKMan]

Hi great advice and thanks.

8 hours ago, phbigred said:

https://wiki.unraid.net/Shrink_array

You can shrink your array, I've done it as few times. If you are looking to reduce the count of disks go with a single parity. Remember it has to be = or greater than the largest drive. Word to the wise... If you are thinking of encrypting later on, you may want to do it from the beginning as in-place encryption isn't available yet. Also confirm your nvme drives aren't using a Marvell controller, known issue with Linux. 

Ironically, I was thinking about how to shrink arrays too, so this is much appreciated advice. Don't think I'll be doing it anytime soon though, but it was definitely on my mind. Thanks for this.

 

5 hours ago, trurl said:

How much capacity do you really need? I would just leave out the smaller disks unless you really need the space now. I always recommend fewer larger disks vs more smaller disks. Larger disks are more cost effective, larger disks have some performance advantages, and fewer disks take fewer connections and have fewer opportunities for problems. And you can always add the small disks later if you need to. Don't install more disks than you currently need.

I currently use all the 3TB disks in a 15TB array on my old (not unRAID) server, but I'm planning to migrate everything to my new unRAID and reuse that as something else. As much storage as possible is what I'd like, until I choose to replace disks with larger ones. 6TB seems a good balance for a while, unless I see some good deals.

5 hours ago, trurl said:

You mention using disks from an old server. Unraid must format any disk it will use in the parity array or cache pool, so if those disks have any data you want to keep you must copy it somewhere if you want to reuse those disks.

At this point, I'll probably just add all of my older 3TB disks in, as that will even things out (As if I was using all the 6TB).

5 hours ago, trurl said:

 

Also, it is important that you only use reliable disks in the array. Parity by itself doesn't allow you to recover any data. Parity plus ALL the other disks are required to calculate the data for a missing disk. Every bit of every disk must be reliably read to reliably reconstruct a failed disk.

I've not had any issues with my old disks, as I tend to swap them out every few years before they become an issue (Or if I see errors occurring).

I currently backup my most important data to a cloud backup, but I do need to think of a new solution that will incorporate unRAID better.

 

Any advice for an unRAID-integrated backup solution? Any plugins or Apps?

[trurl]

4 hours ago, KptnKMan said:

I've not had any issues with my old disks, as I tend to swap them out every few years before they become an issue (Or if I see errors occurring).

Disk problems like I mentioned might not necessarily be apparent. Unraid monitors SMART attributes and will warn you if any look bad. Be sure to setup Notifications to alert you immediately by email or other agent when a problem is detected. You don't want to ignore a problem until it becomes multiple problems and data loss.

[trurl]

4 hours ago, KptnKMan said:

Any advice for an unRAID-integrated backup solution? Any plugins or Apps?

I just rsync my important stuff to external drives mounted with Unassigned Devices plugin. I know there are plenty of other solutions people use. Lots and lots of dockers available for various purposes.