New Storage Build

[BlueBox Studio]

Hello everyone,

it has been a while since my last post on this forum, and I kindly need your help understanding a couple of things.

 

I'm planning to build a storage server (no VMs needed, just unRaid available on a 10G Network), probably starting with 10x 12TB hdd. I am a Pro license user, so correct me if I'm wrong, the limit is 30 disks for the array (actually, I would like to set 2 of them as parity disks), plus up to 24 as cache disks, right? The plan is to start with 10hdd + 2 parity disks + 2 m.2 cache disks, and fill in other drives when needed.

 

My second question is about bandwidth/pci lanes, a thing that I can not fully understand and calculate by myself:

 

To support the potential total of 32 disks (28+2 from the array,  2 of cache that I planned), I'll need HBA cards, but I also need bandwidth to run two M.2 ssds, and a 10G card. What I chose as processor is a Xeon E3-1275v6, and my motherboard of choice was a P10S-WS from Asus. The listed xeon can handle 16pci lanes, so will the described configuration work?

 

And last, again about bandwidth, how many HBA cards will I need to handle the 32 disks (Seagate IronWolf Pro 12TB and 960 evo 250GB)?

 

Thank you in advance,

Regards

[JorgeB]

27 minutes ago, BlueBox Studio said:

the limit is 30 disks for the array (actually, I would like to set 2 of them as parity disks), plus up to 24 as cache disks, right?

Yes, of the 30 two must be parity, i.e. max array is 28 data plus 1 or 2 parity disks, cache pool up to 24.

 

29 minutes ago, BlueBox Studio said:

And last, again about bandwidth, how many HBA cards will I need to handle the 32 disks (Seagate IronWolf Pro 12TB and 960 evo 250GB)?

There are a lot of options, you can for example use a single HBA connected to one or more SAS expanders, e.g., on my 30 disk server I have one LSI 9207 connected to 2 Intel expanders with 12 disks each, remaining 6 drives use the onboard SATA controller, so I'm only using 8 CPU PCIe lanes for the 30 disks.

[BlueBox Studio]

9 minutes ago, johnnie.black said:

Yes, of the 30 two must be parity, i.e. max array is 28 data plus 1 or 2 parity disks, cache pool up to 24.

 

There are a lot of options, you can for example use a single HBA connected to one or more SAS expanders, e.g., on my 30 disk server I have one LSI 9207 connected to 2 Intel expanders with 12 disks each, remaining 6 drives use the onboard SATA controller, so I'm only using 8 CPU PCIe lanes for the 30 disks.

Thank you for your reply. Would you be so kind to tell me what exact model of expander do you use? Moreover, aren't there bandwidth differences between the HBA connected disks and the one directly attached to the motherboard?

 

And last, if I can: what's the minimum amount of disks to have both two parity disks and two cache disks setup from the beginning, so no need to do tweaks later on when more disks are added to the array (since I saw a couple of videos and the process requests relatively a lot a time)?

 

Thank you again!

[JorgeB]

17 hours ago, BlueBox Studio said:

Thank you for your reply. Would you be so kind to tell me what exact model of expander do you use?

Intel RES2SV240

 

17 hours ago, BlueBox Studio said:

Moreover, aren't there bandwidth differences between the HBA connected disks and the one directly attached to the motherboard?

Not quite sure what you mean here, there are differences in bandwidth but the only thing that matters is that none of them is a bottleneck when all disks are in use, like during a parity check or disk rebuild.

 

17 hours ago, BlueBox Studio said:

And last, if I can: what's the minimum amount of disks to have both two parity disks and two cache disks setup from the beginning, so no need to do tweaks later on when more disks are added to the array (since I saw a couple of videos and the process requests relatively a lot a time)?

 

One data disk.

[BlueBox Studio]

Thank you for your reply.

 

So as a recap, to be sure to not set on fire the whole thing:

 

The chassis I chose is a 24 bay ad has 6 mini SAS connector 8087. To connect them, I need a card like your Intel RES2SV240, but a Raid card in my case is *not* necessary since I don't need to use a raid configuration, but I'm planning to run straight from unRaid, is it correct? And from the Intel card to the back panel I go with 8087-8087 cables.

[JorgeB]

To connect them, I need a card like your Intel RES2SV240, but a Raid card in my case is *not* necessary since I don't need to use a raid configuration

An expander doens't work on it's own, you still need an HBA, like an LSI 9211, 9201, 9207, etc.

 

 

 

 

[BlueBox Studio]

Ok, so if I'm using your same Intel expander card, one of the 6 connectors will be linked to one of the connectors on the raid card, isn't it? I'm thinking about buying two LSI 9201-8i because it's plain HBA, works out of the box with unRaid it's cheap.

 

Thank you for the support!

[JorgeB]

1 hour ago, BlueBox Studio said:

one of the 6 connectors will be linked to one of the connectors on the raid card, isn't it?

Correct, though to avoid confusion you should call it an HBA, RAID controllers are not recommended for unRAID, LSI 9201 is a good option, and plug'n play, but it could be a bottleneck with many disks because it's PCIe 2.0, if you plan on having many disks connected also consider the 9207 since it's PCIe 3.0.

[MvL]

Thanks Johnnie for mentioning the LSI 9207. Didn’t know it was pci-e 3.0. I always assumed that I needed a LSI 9300..

Edited April 9, 2018 by MvL

[BlueBox Studio]

Really thank you for the support! I'm going to order the whole thing soon. The last piece missing is the rack cabinet.. in Italy I only can find them from 22u and up.