TrueNAS to backup multiple Synology : Hardware

[Mitch_ch]

Hi,

I will build a TrueNAS based on HP DL380p G8 with 12 LFF.

The disk controller will be a P420 with 2Gb of Cache, but naturally with no RAID Array

I project to use :
CPU : 1 x E5-2650L V2 (10 core)
RAM : 64 Gb RAM ECC HP certified
Netwotk : 1 HP card with 2 x 10Gbs (SFP+) and 4 x 1Gbs (on board)
SSD : 2 x WD SA500 of 500Gb (OS + Cache)
HDD : 10 x 16Tb Seagate Exos X16 (Enterprise quality)
PS : 2 x 450W HP

I will use this server to backup 3 Synology with Rsync (Total of 40 Tb)

Questions :

1) Is the RAM suffisant for 160Tb of disks ?
2) Whats is the best an safest configuration for the 10 disks :
2 a) 1 volume of 9 disks in ZV2 (RAID6) with one disk in spare ?
2 b) 2 volumes of ZV1 (RAID 5) without spare
2 c) other proposal ?
3) Is the CPU suffisant powerfull to make deduplification ? (I can put on or two E5-2697 v2, but the electricity consumption will grow rapidely...)

Thanks in advance for your help and support.

Regards,

Mitch

 

[jgreco]

ZV2 (RAID6)

ZV1 (RAID 5)

You mean RAIDZ1 and RAIDZ2? I've never heard of ZV1 or ZV2. We strongly recommend using the correct terminology for things, because communicating clearly typically results in more people understanding your meaning. Additionally, this is an international forum, and some people are struggling even to do the translation back and forth to English.

Terminology and Abbreviations Primer

We realize that new users have a lot to learn when they come to FreeNAS. There's a certain amount of confusion added to discussions when users pick random/approximate terms to describe things. I've spent a lot of time quietly trying to...

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The disk controller will be a P420 with 2Gb of Cache, but naturally with no RAID Array

This is not acceptable.

What's all the noise about HBAs, and why can't I use a RAID controller?

1) An HBA is a Host Bus Adapter. This is a controller that allows SAS and SATA devices to be attached to, and communicate directly with, a server. RAID controllers typically aggregate several disks into a Virtual Disk abstraction of some sort...

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I mean, I can't stop you from using it, but you'll run into problems, and then it may be too late to help you, if your pool is already trashed.

1 HP card with 2 x 10Gbs (SFP+)

Note that HP often uses the Broadcoms, which tend to not work well. Please head on over to the 10 GIg Networking Primer for a discussion of cards known to work well. This boils down to the leaders of the pack, such as the Intel X520 or Chelsio T520-CR, or second-place choices such as the Solarflare or Mellanox ConnectX cards (read up before buying).

10 Gig Networking Primer

This is a discussion of high speed networking for newcomers, with specific emphasis on practical small- to medium-scale deployments for home labs or small office users. It originated with a forum thread located here that has many pages of...

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1) Is the RAM suffisant for 160Tb of disks ?

Without deduplication, it should work but it won't be as fast as if you had sufficient RAM.

3) Is the CPU suffisant powerfull to make deduplification ? (

CPU isn't the main issue for dedup; memory is. The actual number needed is tied to specifics such as block size, but the rule of thumb is that you should expect to need 5GB of RAM per TB of data. Because you say you're backing up only 40TB, but have a 160TB pool, I think if you were to start out with 128GB, and then keep an eye on it, with an expectation that you might have to go up to 256-512GB, that is the winning gameplan. Dedup is a minefield of need-to-know issues, and the biggest one is that it isn't actually magic. Deduplication only works against actual duplicate data. If you are expecting to be storing the same copy of a block only twice or thrice, you may not get much of a benefit from dedup. If you are storing it dozens of times, then it's useful. Of course it has to be LOTS of blocks, such as uncompressed VM backup images and other things like that where the duplicate blocks can be identified by ZFS.

 

[Mitch_ch]

Hi,

Thank you for your quick reply. I'm a "newbie" with TrueNas.

I first excuse me for the bad terminology. You're right It is RAIDZ1 and RAIDZ2. I will take care of that for the futur.

About the P420i (embeded HP RAID controller). The NAS is not build for the moment and I can change a lot of things if necessary. That why I need your expertise.

On the P420i you can attribute disk "alone" with "RAID0" mode into the controller. Would it be correct or do you propose another solution ? (LSI SAS 9260-8i controller or something else). The server has a backplane for 12 disks, this is a SAS Expander with 2 SFF8087.

After your explanation I will not deduplificate and I will put in place 256Gb of RAM

I found an Intel E10G42BFSRBLK X520-SR2 10GB on eBay and will disable the HP onboard card.

I mean we progress...