10 1TB drives configure as 5x2x1000GB or 2x5x1000GB

[Jay629]

Hi there,
am new to FreeNAS and thinking to run FreeNAS for home storage sharing files (mainly media files sized a few GBs) across Windows(computer) and android(mobile), the pool will be a bunch of HDDs; currently thinking 10, or might use 12 if more optimal.
The first question I have is while creating the volume, I was given the option like this:


Looks like this is a big RAID6 equivalent.. it just looks kind of awkward to me lol...To improve the performance a little, I was thinking to do two RAIDz, then stripe across the two RAIDz. So I try to drag the graph, I get this:


It gives the same useable capacity as two RAIDz, but the graphs looks like I will be getting a single RAIDz that has 5 vdev, each contains a two-drives-RAID0. Which one should work better?
It seems to me that the 2nd one is more problematic as it has more RAID components..

Any advise?

Thanks~

 

[Jay629]

Just to clarify, by which one works better I mean:
one RAIDz that contains five 2-drive-stripe
or
two striped RAIDz that each contains five 1-physical-drive

The one RAIDz2 with 10 drives seems to be the best regarding drive failure tolerance (as it allows any two; the other two options need to be a certain 2 not any) , just a little odd to see 10 drives in single RAIDz2...well, if nothing really wrong with this option I would just go with this one anyway

Any thought?

 

[SweetAndLow]

don't use raidz if you don't have to. I would choose to do 10disk in raidz2

 

[danb35]

Just to clarify, by which one works better I mean:
one RAIDz that contains five 2-drive-stripe
or
two striped RAIDz that each contains five 1-physical-drive

The question is irrelevant, since the first configuration is impossible. What the volume manager is offering to create is the second configuration. But I would also vote for the 10 X 1 TB RAIDZ2 configuration.

 

[depasseg]

Looks like this is a big RAID6 equivalent.. it just looks kind of awkward to me lol...To improve the performance a little, I was thinking to do two RAIDz, then stripe across the two RAIDz. So I try to drag the graph, I get this:
View attachment 8039

It gives the same useable capacity as two RAIDz, but the graphs looks like I will be getting a single RAIDz that has 5 vdev, each contains a two-drives-RAID0. Which one should work better?
It seems to me that the 2nd one is more problematic as it has more RAID components..

I think you are mis-interpreting this graph. I think this is 2 x 5 Drive RAID-Z vdevs. Stripes/RAID0 don't enter this config. I would also recommend 10 drive RAIDz2.

 

[Jay629]

I think you are mis-interpreting this graph. I think this is 2 x 5 Drive RAID-Z vdevs. Stripes/RAID0 don't enter this config. I would also recommend 10 drive RAIDz2.

Ah I though it should be this way too but the 1|2|3|4|5 on the header line leads me to that interpretation lol..
Anyway, as everyone recommend, I would just go with the 10 drives RAIDZ2~

Thanks for all the quick replies :)

 

[toadman]

The question is irrelevant, since the first configuration is impossible. What the volume manager is offering to create is the second configuration. But I would also vote for the 10 X 1 TB RAIDZ2 configuration.

I can't remember what the volume manager will/won't allow, but I interpreted the first config as 5 x 2-drive mirror vdevs. That is valid for sure. I run it in my server.

For media files, in a similar situation I'd probably run 12 disks in a 2 x 6-disk RAIDZ2 config. i.e. 2 vdevs of 6 disks, each configured in RAIDZ2. If you haven't bought the disks yet, any reason you are looking at 1TB vs. 4+TB? The $/GB is undoubtedly less on the larger drives. If you have the drives already, makes total sense. :)

 

[toadman]

Ah, I see. Yes, this doesn't make sense..."one RAIDz that contains five 2-drive-stripe". I didn't read carefully enough. Sub "pool" for "RAIDZ" and it makes (some) sense.

 

[Jay629]

@toadman
Thanks for the replies,
I though the graph indicates five 2-drive-stripe too...
but anyway, as everyone suggests I would just go with 10 drive raidz2.
I got the drives in an old system from the 2011...surprisingly all still have warranty til 2016(the remaining of 5-year).. all tested good so would just continue to use them anyway~
I though about two 6-drive-raidz2 too, but that seems to waste a lot of capacity :( don't really need that much redundancy at this point lol~