[OmniOS-discuss] Request advise on pool upgrade

[Andries Annema]

Now that, "my dear Watson", is an interesting 4th option!
The usefulness of one large single pool to house all my data and never 
bother shoveling data around over pool borders - as I did in a previous 
pre-zfs era with disk partitions - has always been my goal with this 
build. But, maybe, a compromise is a viable option to ease the process 
of upgrading once in a while. Maybe, focusing on one single pool is in 
itself too much of a disadvantage after all.

I'll give this some thought.
Thanks for sharing!

Cheers,

Andries


On 2018-02-07 11:08, Olaf Marzocchi wrote:
> You have a big pool with many vdevs and that makes, as you noticed, 
> upgrades difficult
> I guess you don't need exceptional performances, isn't it?
>
> Go then for 8 TB and option 1, creating a new pool as big as the 
> previous one. Use the opportunity (the last one you'll have!) to move 
> everything there, then split the previous one into two.
> When done, redistribute, as much as possible, the datasets between the 
> three pools.
>
> At least in the future you will be able to use two pools as temporary 
> backup for the third one if you need to take one offline for any reason.
> This trumps all the other advantages and disadvantages IMHO.
>
> Olaf
>
>
>
> Il 6 febbraio 2018 21:27:43 CET, Andries Annema 
> <an3s.annema at gmail.com> ha scritto:
>
>     Hi guys,
>
>     Could you please give me some advise on the best way to increase
>     the capacity on my home server (running OmniOS obviously...)?
>
>     About four years ago I started designing and building my home
>     storage server based on a "Coolermaster Stacker" tower case by
>     retrofitting into it three Norco SS-500 and one SS-300 hotswap
>     modules, for a total of 18 hard drives.
>     With this number of drive bays available, I choose to go for
>     RAIDZ2: three vdevs of six drives each.
>
>     Back in 2014, I started with only one vdev of six 4TB WD40EFRX
>     drives. About a year later, in early 2015, I put another six of
>     those drives in and expanded the pool. It has been humming happily
>     ever since. Awesome.
>
>     Over time however, the used pool capacity has now gone up to 86%.
>     It's time to expand again.
>     I see a number of possible ways to do so:
>
>      1. Get another six 4TB WD40EFRX's and fill the last open bays,
>         adding a 3rd vdev (capacity +50%).
>         Pros: these drives are cheap nowadays, much cheaper than they
>         were three or four years ago.
>         Cons: six extra spindles will increase electricity cost.
>      2. Get six 8TB WD80EFZX's and fill the last open bays, adding a
>         3rd vdev (capacity +100%).
>         Pros: huge capacity increase.
>         Cons: higher upgrade cost than option 1 (due to more expensive
>         drives). Six extra spindles will increase electricity cost.
>      3. Get six 8TB WD80EFZX's and *replace* the first vdev with
>         bigger disks (capacity +50%).
>         Pros: amount of spindles doesn't change and thus electricity
>         cost will more or less remain the same. Replaced drives can be
>         utilized elsewhere, e.g. for offline pool-backups.
>         Cons: higher upgrade cost than option 1 (due to more expensive
>         drives).
>
>     The first question that comes to mind for option 2 and 3: are
>     there any disadvantages to creating a pool out of different
>     capacity drives? The drives per vdev are identical, it's just the
>     vdevs within the pool that aren't.
>
>     Right now I am leaning towards options 2 or 3, with maybe a little
>     preference for option 3, I think.
>
>     Any thoughts you guys can share on this matter? Would appreciate
>     it. Thanks!
>
>     Regards,
>
>     Andries
>

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