SOLVED Question about hardware Dell machine in relation with ZFS

[Ryze]

Hi,

Suppose I want to buy a Dell Precision 3440, it's a Dell workstation, how well will ZFS work?

Purpose of this thread is to understand in detail how the above mentioned machine will work with ZFS.

Here some info about the setup possibilities:
- The machine does not have a HBA controller.
- When selecting RAID controller there is the option no
- When reading the specs or manual , there is a intel internal sata controller

My question is how well will the machine run without changing the machine, so no hardware flashing or not adding a HBA or other changes. How well will it run and what could be the disadvantage(s) of not changing anything to the configuration?

Best Regards,

R

 

[Constantin]

ECC memory is optional per Dell, I would go for it. Ideally 32GB or more RAM.

How well it'll work is a different question. How many disks are you trying to house in it, what is your use case, etc? We cannot answer your question re: hardware without a good idea what you're trying to accomplish? Plain file server? Virtual machine host? Transcoding plex Server? Etc. How much data you want to host, what CPU, etc.

HBA can be added easily via LSI PCIe card. However, between the size of the enclosure and the product descriptions, I wonder just what ZFS system makes sense on this platform. Not saying it cannot be done, but a 10TB limit suggests that internal storage is limited to a single 2.5" drive.

 

[Ryze]

Hi,

Reading about ECC, I understand your point. ZFS works better with more RAM and without ECC the errors in memory could create corrupt data, right?

Okay so with ECC my initial idea is not really valid, so i will have to pick another machine (configuration wise its not possible). Precision 3650 Tower is more suitable.

- How many disks: 3 (2.5 inch drive)
- File server + some media like picture, movies and sound recordings.
- How much data: 3 or 4 TB
- CPU: I prefer XEON

The role of the pc is really a workstation, absolutely there is a limit here hè, yes. It's not a storage box.

- Why would ZFS not make sense for example or you see other disadvantages?

Best Regards,

Kim

 

[rvassar]

The role of the pc is really a workstation, absolutely there is a limit here hè, yes. It's not a storage box.

- Why would ZFS not make sense for example or you see other disadvantages?

I've used Dell Precision T3500 in the past for both FreeNAS & ESXi. They're kind of the "duece and a half" (military truck) of the PC world. Surprisingly adaptable. Most of the Precision towers will optionally support ECC memory, a variety of Xeon server processors, and have some support for advanced GPU cards. I even picked up a T3500 for $70 a few years back, dropped a modern GPU and 6-core Xeon in it and used it as a sleeper gaming rig.

The limitations are going to be configurable memory and number of disks. Though you should be able to configure an LSI controller with an external SAS port and use a JBOD config if you really wanted to. I would suggest something newer like a T36x0 for the more modern CPU (microcode fixes) & lower power consumption.

 

[Ryze]

Hi Rvassar,

Ok so you did not experience any real disadvantage, i mean i read some things like:
- When a disk crashes , because ZFS does not have full control (as there is no HBA) it was difficult to restore data. You did not experience anything like that?
- Or that the speed is reduced because of no HBA?
- Or are my above 2 points not valid?

Best Regards,
R

 

[ChrisRJ]

Plain SATA ports on the motherboard are perfectly fine as well. Just make sure they are configure for AHCI

 

[Constantin]

There is a preference here generally towards either direct connections to the motherboard or LSI HBA’s simply because both are generally stable where other hardware solutions are not.

When folk here talk about direct connections, they mean that there is nothing in between that prevents the OS from accessing the disk via the SATA/SAS directly like a RAID controller that aggregates the disks under its management and presents them as a bigger single drive. Similarly, a lot of folk here (including me) have had bad experiences with inexpensive SATA port multipliers.

another popular preference here is the avoidance of Realtek Ethernet interfaces in favor of Intel and like premium Ethernet chipsets. TrueNAS support for N-baseT chipsets is only starting to roll out so I would stick to SFP+ or Intel Chipsets for 10Gb/s+ networking.

 

[rvassar]

Hi Rvassar,

Ok so you did not experience any real disadvantage, i mean i read some things like:
- When a disk crashes , because ZFS does not have full control (as there is no HBA) it was difficult to restore data. You did not experience anything like that?
- Or that the speed is reduced because of no HBA?
- Or are my above 2 points not valid?

Best Regards,
R

ZFS has full control from the motherboard SATA ports. The only limitation you may hit on older systems is some of them don't support drives larger than 2Tb, and you may have a mix of SATA II & III ports. But that's getting pretty far in the past at this point.

On the topic of "direct control"... It is recommended that ZFS have direct control of the disks. Which is to say, no hardware RAID underneath it. You can configure ZFS on a hardware RAID device, but ZFS will not have much ability to optimize its own performance, the hardware will interfere, and more importantly ZFS will not be able to detect hardware failures. You would be entirely reliant on the hardware solution to monitor and alert you, and solve the problem. Modern RAID controllers also perform more subtle optimizations that interact poorly with ZFS. For example, modern LSI cards can present a "ePD-PT" and call it a JBOD disk. This presents as a dedicated assigned disk, but the controller is performing read & write caching, and this introduces slew in the ZFS ARC statistics, causing ZFS to make incorrect assumptions about the device performance. The device's performance may suddenly change if another thread saturates the RAID controller's CPU, or flushes it's cache, etc...

 

[Ryze]

Interesting, learned a lot from all your reactions. Thanks rvassar, Constantin, ChrisRJ. Clear explanations, thank you so much!