Storage & NAS Servers

If you have no rack and want peace and quiet, a tower server such as the Dell T440 with eight 3.5-inch bays is the better route to your own NAS server.

The models: Dell R740xd and Supermicro SSG-6049P

The R740xd is the compact option and, with Xeon Gold CPUs, doubles as a virtualisation host with local storage. The SSG-6049P is built for capacity per rack unit and connects its bays through expander backplanes. For SSD pools, the R740xd with 24 SFF bays from our rack servers is the better fit.

TrueNAS and ZFS: pool layout, RAM and cache

ZFS needs direct access to every disk, so choose the HBA330 for the R740xd; the Supermicro comes with its HBA fitted. To retrofit other servers, an HBA such as the LSI 9300-8i does the job.

• Pool layout: for archive and backup, RAIDZ2 with six to ten disks per vdev is a proven choice. Twelve bays give you two vdevs of six disks, 36 bays roughly four vdevs of nine. For VMs and databases, mirrored vdevs deliver far more IOPS.
• Memory: ZFS uses free RAM as a read cache (ARC). 192 GB of ECC RAM is plenty for most pools; only deduplication needs considerably more.
• SLOG: a separate log device only speeds up synchronous writes, such as NFS for VMware or databases. Use an SSD with power loss protection, such as the Optane P4800X.

Hard drives, networking and power

For capacity, 3.5-inch NL-SAS disks at 7,200 rpm are the standard choice, such as the Seagate Exos X12; all models are under SAS hard drives. Avoid SMR disks for ZFS and RAID. For fibre or 25 GbE, our network cards include SFP+ and SFP28 models. Factor in power, too: 36 hard drives alone draw a few hundred watts in operation. Our guide SAS vs SATA vs NVMe explains the interfaces.