(SOLVED) Disk SpinUp with Plex and a couple other questions

[SmokeyColes]

Hi 

 

I just read that using Unraid the disks spin up as needed and down when not needed to help maintain hdd life.  It is meant to be ideal as a PLEX server.  Is this correct, using PLEX as a docker app?  Also would it still be true running PLEX within a VM with a mount to the shares (disks run up/down as required)?
I am conscious as I want to run PLEX in a VM (reason being is I plan to run it with Kodi and limited on pcie slots for GPUs and want to use the GPU for hardware transcoding, as well as sending Kodi via HDMI around the house)(the other VM using the other HDMI).

I imagine both docker/vm spin up/down as required?

 

Second question, a SATA expansion is used on pcie 2.0 x1 

https://www.amazon.co.uk/dp/B0828FY1B2/ref=cm_sw_r_cp_api_glt_fabc_D4FGSE74EC63GZQFP1BJ?_encoding=UTF8&psc=1

it says it can achieve communications up 2.5gbs, however I would have thought it would be more like 500mbps.

it says it supports 6gb/s devices but they wouldn’t be running at 6gb/s.  If the. Mechanical drives really only read/write at say 100mb/s.  Why bother having sata interfaces at 6gb/s?  Is this purely a concern for sata SSD.  (I’m assuming NVME only works in M2 slots).

 

Now in my unraid test rig - I don’t have PCIe 3 which is needed for my M5110 HBA controller (it looks pretty unused next to my server!) the master plan is - that it is going to a SAS backplane for 8 drives.  Going back to question 2 why is this using a PCIe 3.0 x8 slot (minimal) for 2xSAS (8 drives)?  Is this because of a single cable is being used and I could have 4 SSDs?  I’m just confused why I can essentially do the same on this dubious pcie2x1 yet the hba is pcie3x8?
 

Question 4 why would I bother with SAS and HBA when I could use a pcie to 8 sata ports? I choose the HBA because of a Linus video where he connect something ridiculous like 20 something 16TB drives.  But he explained about the HBA with octopus’s to sata.  But why not use this pcie card to sata!  he also mentioned to get one not designed for raid.
The server rack I want has either 16 or 24 hotswap drives (4 mini sas or 6 mini sas).

I guess I’m struggling to see why a hba would be better in this case, there’s clearly a reason it has a sas backplane??

 

Apologies for the fundamental learning questions here.

 

I have been toying with an idea of my final rig being a supermicro board with 4x pcie 3.0 LGA1200 for cpu transcoding 10900K and 2VMs (2x HBA, 2x GPU).  

Though today I also contacted OneStop to ask how much an expansion board and kit would cost (I imagine a lot! And would be curious if anyone else has done similar using these expansion boards/kits and got quotes)?

Thanks

Chris 

 

Edited April 26, 2021 by SmokeyColes

[Zonediver]

12 minutes ago, SmokeyColes said:

im concerned as I want to run PLEX in a VM

 

There is no need to run Plex "within" a VM - just install it "normal" under Docker.

Edited April 24, 2021 by Zonediver

[kizer]

Plex runs natively as a Docker very well. I think adding Plex to a VM is just unnecessary overhead. 

[JorgeB]

13 hours ago, SmokeyColes said:

Second question, a SATA expansion is used on pcie 2.0 x1 

Avoid controllers with Marvell chips and controllers with SATA port multipliers, that one has both, see here for a list of recommended controllers.

[SmokeyColes]

@JorgeB this post link is really useful.  I sort of wish I knew it existed before I bought what I did, and could have asked some pros!

Am I correct then in saying that posts doesn’t recommend the M5110 flashed with the p20 IT firmware (which I bought from eBay saying it was good for unraid)?  The M5110 is pcie3.0  x8 as a minimal and gives me 2x miniSAS or 8x SATA

If I want a full 24; the post recommends a HBA 9305-24i (which is about £500 on eBay).  It does a full 24 drives and only needs a single slot?

 

Does the RES2SV240 require a HBA controller to link up?  Do you have a recommended one I could use for the 24 HDDs?

What is the minimal in pci requirements?  Gen and slot size?

 

Sorry the post is good but I feel it’s a bit above my current capability to understand correctly as intended.  It’s also looks more expensive than I had considered.

 What is clear to me is to avoid cheap devices I found on Amazon, no doubt.

 

Thanks for any help.

unraid would really benefit for some newb guides on this matter, with some suggestions Ba drive size and speeds.

[JorgeB]

2 minutes ago, SmokeyColes said:

the M5110 flashed with the p20 IT firmware

That's a very good option, and it doesn't require a PCIe 3.0 slot, it will work on a 2.0 slot, that controller uses the LSI 2308 chip, it's one of the recommended ones in the link above.

[SmokeyColes]

Great as the eBay person did seem very knowledgable and really really helpful.  But it does say it needs pcie 3.0.  But it sounds like you also know your stuff.  
 

So do you support the idea of using 3 of these or a sas expander like the HP 468406-B21 or IBM 46M0997 ServeRAID Expansion Adapter 16-Port SAS Expander. The IBM I’ve seen a video which shows how it can be used  as a 24port 

 

My thinking is the HP will be better as I think the 46M0997 has less bandwidth?  
 

really curious to know your thoughts on if it is pcie3.0 or 2.0 (as that has potential to resolve loads of issues). Also if you think 3x HBAs or one HBA with one of the 2 expanders  and if so which expander?

 

thanks

chris

[JorgeB]

23 minutes ago, SmokeyColes said:

But it does say it needs pcie 3.0.

It doesn't.

 

24 minutes ago, SmokeyColes said:

Also if you think 3x HBAs or one HBA with one of the 2 expanders  and if so which expander?

You can take a look here for some performance numbers:

https://forums.unraid.net/topic/41340-satasas-controllers-tested-real-world-max-throughput-during-parity-check/