How to Configure 5x16TB HDDs and 2x2TB SSDs

[Jim Reese]

I have a TrueNAS mini X+ which I just got up and running, with 5 16TB HDDs and 2 1.92TB SSDs. Any thoughts on how to configure this? The system has 32 GB RAM.

My thoughts: HDDs in a raidz1 (raidz2 just seems so wasteful—32TB down the drain ) for "regular" files, SSDs in a mirror for real-time audio (Logic X recording/mixing) and video editing (shotcut and iMovie).

Should I use part of the SSDs for SLOG/L2ARC?

Thanks in advance for any advice and thoughts.

Jim

 

[Jim Reese]

I understand that most people think that I should put the 5 16TB drives in a raidz2 config. Any idea what the resilvering time would be if I did raidz1?

Jim

 

[ChrisRJ]

Should I use part of the SSDs for SLOG/L2ARC?

No:

• It is not supported. So while it might work (others will have to tell that), it would be a fragile construct with a high risk of loosing all data on it.
• SLOG: Not needed for your use-case
• L2ARC: You will need at least 64 GB RAM to make it work properly

 

[sretalla]

HDDs in a raidz1 (raidz2 just seems so wasteful—32TB down the drain ) for "regular" files

Do that at your peril... or mitigate the peril with a bulletproof backup strategy if you care about the data... but be prepared for a long process to restore the pool when you have a second failure during resilver.

Should I use part of the SSDs for SLOG/L2ARC?

No.

 

[Jim Reese]

Thanks for the replies. Looks like I'll go with raidz2 for the HDDs. (And mirror the SSDs.)

My plan is to use the HDD zpool as my home directory, while I want to use the SSDs for real-time processing of audio (Logic X recording/mixing) and video (shotcut and iMovie).

Question: Should I use iSCSI as the mechanism to best achieve this?

Thanks again!

Jim

 

[ChrisRJ]

Question: Should I use iSCSI as the mechanism to best achieve this?

No, SMB. Why do you consider iSCSI?

 

[Jim Reese]

I considered iSCSI because I thought that it was the only way to be able to have the zpool mounted as, say /home, while SMB is only a file service. I am probably showing my ignorance here, as I'm strictly a Linux (Unix) and Mac guy; I've never even owned a Windoze box.

It seems like you're saying that if I share/export the zpool via SMB, I can mount it as /home on my Mac and Linux boxes and use it for my home dirs. Is that correct?

Jim

 

[ChrisRJ]

In my view it is not a good idea to move the entire home directory on a NAS. It creates a hard dependency. Also, what if you use multiple machines and want some settings differently? What, if Linux and Mac expect different content in a file with the same name?

 

[Jim Reese]

In this case, the entire home directory is just for one person on one machine (me in my recording studio), so I won't be changing settings and I'll be using the same machine (a Mac) always. Is it still a bad idea in this scenario.

Jim

 

[Jim Reese]

Update: I'm upgrading the memory tomorrow from 32GB RDIMM ECC to 128 GB (the max). Would this amount of memory change my using part of the SSDs for SLOG/L2ARC?

Thanks!

 

[sretalla]

Not unless your working set is enormous.

Generally, adding RAM is the right thing to do. Don't use SLOG until you understand it (and understanding it will tell you not to mix it with other uses on a device). Don't use L2ARC unless you already show you have a low hit ratio on ARC (use arc_summary to see that after you run real workloads for a while)

 

[Jim Reese]

We'll see how things go after I up the RAM and add the pools and start to use it.

Thanks for your advice.

Jim