Storage Spaces Mirrors - one big one vs several small ones?

[Gerr]

I am in the process of setting up my new home server for NAS & Plex usage.  I know what I am doing for Plex, but not sure how to handle my NAS setup.  I plan on having 3 NAS shares, one for me, one for my wife, and one for family photo's & videos.  I am debating on if I should make one large MIRRORED NAS pool(6xHDD) and just create 3 folders on it with each folder being it's own share.  OR, I could create 3 separate (2xHDD) mirrors, one per share.  And yes, I do have these backed up.

 

I think the popular path would be to create one large mirror.  However, that places ALL my data at risk if I have more than one drive fail.  Plus if I have to rebuild the whole array with a single drive failure, it stress out all the other drives.  I could do a 3-way mirror, but that reduces my overall storage space or forces me to buy additional HDD's.  With 3 small mirrors, if I have a HDD fail, when I rebuild, only one HDD is stressed and if it fails too, I only lose the data for that mirror, not all of them.

 

Thoughts?

[Electronics Wizardy]

Do you plan to expand the volume by adding more drives or replace them with bigger ones? How much do you care about speed.

 

Id just make one large mirror with columns set to 3 to get the most speed, and make one big volume. Id make it thin provisioned just in case you wanted another volume for something else.

 

You can also have 3 mirrored volumes, and make them all thin provisioned, and let them expand 

 

21 minutes ago, Gerr said:

With 3 small mirrors, if I have a HDD fail, when I rebuild, only one HDD is stressed and if it fails

I think this is the case with one large mirror across all disks, but haven't tested it in storage spaces.

 

[Gerr]

For right now, the storage I am providing, that being 3TB to each personal share and 4TB to the media share, should be plenty for several years.  When I do upgrade, who knows, but likely larger drives as my server can only support a limited number of drives and it's basically maxed out currently.  But by that time, I might overhaul it.  It's already old due to my lazyness, have had the main hardware going on 3 years, and only now getting it up and running.  It has a E3-1271v3 on a Asus C226 WS mobo with 32GB DDR3-1600 ECC.  That was only one generation old when I bought it, now it's much older, but still plenty for a Plex & NAS server.

[Mikensan]

Just to add - it won't stress the whole array when rebuilding a mirror'd disk since it is not a partiy array. I would also suggest emai alrts so you actually know when a disk fails since you won't see a performance hit.

[Xplo1t]

Even in a mirror setup it would be 1-3 disk failures with 6 disks before it would be lost.  When I built my Windows 2019 server, I only divided up the pools based on speed.  The archive pool is 6x8TB + 2 x 1TB SSD in a tiered layout,  The higher performance tier is 10 x 6TB + 2 x 1TB NVMe.  Under that are various volumes depending on use and performance tier allocation.

[Gerr]

SSD's needed on a mirrored set?

[leadeater]

10 hours ago, Gerr said:

SSD's needed on a mirrored set?

No, mirror setups perform very well with just HDDs. If you want higher performance you can add SSD + tiering but that's more in the 'cool numbers' area than something actually needed.

[Gerr]

Thanks, that's what I thought.  I imagine it would be good if using parity though, correct?

[Xplo1t]

7 hours ago, leadeater said:

No, mirror setups perform very well with just HDDs. If you want higher performance you can add SSD + tiering but that's more in the 'cool numbers' area than something actually needed.

Not sure you are the right person to be making the call on what's needed.  Leave that to the use case.

[leadeater]

8 minutes ago, Xplo1t said:

Not sure you are the right person to be making the call on what's needed.  Leave that to the use case.

The use case here is Plex and media storage, SSD performance isn't required for that. To get end to end utilization of that performance capability you need to add on 10Gb networking and the added benefit is rather low here.

 

Sure other uses cases like VM hosting would benefit well from it, or if you had specific high performance network storage requirements.

 

Regardless for seq performance a fairly reasonable number of HDDs will also saturate 10Gb networking. The bigger gains is in random I/O and mixed read/write.

[leadeater]

5 hours ago, Gerr said:

Thanks, that's what I thought.  I imagine it would be good if using parity though, correct?

Yes, if your HDD tier is parity SSD Journal or SSD tiering is a must. Storage Spaces parity is rather poor write performance, often matching a single HDD area. I get pretty good performance with such a configuration but it's something I would only use for Plex or other types of bulk primarily read workloads, I use it for Plex.