LSI Disk Shelf advantages (ZFS -- True / Free NAS)

[TrumanHW]

Read a few Disk Shelf threads but have a couple of questions before I can take the plunge.

Use: ZFS / TrueNAS (home / 2-3 users max) …

1. Aside from generation (ie., use SAS-2 with IOM6) do I need SAS controller(s) – say,

• 1x 16e
• 2x 8e
  … if it’s connected to a Disk Shelf with 16 SAS-2 devices…?

OR, do I just need a SAS card with adequate bandwidth…?
Ie: An 8e SAS-2 has 8x 6Gb or has theoretical bandwidth of ≤ 6GB/s …?

(if I’m not mistaken, I’ve seen cards that can “address 1024 LUN” .?)

So you could theoretically connect a couple of 12x 3.5" DS to a single controller …? as they daisy chain to your SAS card (with adequate bandwidth, of course) … or, using a SAS to SFP+ or QSFP+ cable … which apparently can allow the data to ‘cross protocols’ (yet another means in addition to iSCSI which – if my assumptions aren’t idiotic, NIC cards can boot up) …?

For instance, this Oracle document might be saying (on the top row:
A … ZS5-4 with a SAS2 (16e) 4 port with 4 SAS-2 lanes per port, could control up to (4) 24 HDD disk shelves …? Which almost makes sense? Assuming ~200MB/s (max) for 7200 rpm 3.5" drives (when empty, large files, etc) … and a hypothetical per SAS-2 channel 600MB/s ? would mean 3 HD per channel … and 3x 16e would be 2 (not 4x 24x disk shelves) … but this shows 4x 24 disk …?

Wendel used only that yellow Dell (google R730?) to control his DS, yeah…?

And way down on the importance…
Anyone ever heard of a projects to replace stock NetApp DS fans with quiet(er) fans …?

Thanks in advance.

[Razor_Blade]

The Netapp ds4243 and 4246 shelves can be daisy chained so multiple shelves can exist on a single cable connection. You can use a regular LSI card with the SFF external connection, you just need the QSFP+ To SFF**** cable depending on your card. You can also check the IOM12 it is an expensive option and may not be compatible with all disk shelves but it ditches the QSFP connection. You do only need one controller and one cable but can run multiple for redundancy and have the multiple paths this can quickly up the power consumption so it isn’t something I do.

Not 100% sure on this but I believe if you do use more than one controller you will need to either use SAS drives or an interposor board for your SATA drives.

Also there are people that mod a replacement fan in the power supplies. I wouldn’t recommend it because it involves opening a power supply and they’re a real pain to remove those fans…plus a shelf full of SAS drives gets pretty toasty so that could be a consideration not to if that’s your use case.