A Gentle Introduction to ZFS, Part 2: Storage Pools and Hard Disk Drives on the Jetson TX2

ZFS Storage Pool Configurations (Source: Louwrentius)

Introduction

ZFS Storage Pools

ZFS Storage Pool Diagram (Source: iXsystems)

Storage Pool Capacity

Storage Pool Throughput

Jetson TX2 Gigabit Ethernet Port
  • 2 drives = 200 MB/s
  • 3 drives = 300 MB/s
  • and so on…

Expanding the TX2’s Drive Capacity

Jetson TX2 SATA II (3Gbps) Port
Jetson TX2 PCI-e Gen2 x4 Slot
Syba PCI-e Mini SAS Expander (SI-PEX40137)

Computer Case and Noise

Fractal Design Node 804 Micro ATX Chassis

Creating the ZFS Storage Pool

$ sudo zpool create -f tank \
-m /tank
draid2 \
wwn-0x5000c5003824cced \
wwn-0x5000c5004e7ea309 \
wwn-0x5000c5004e8031df \
wwn-0x5000c500a3d0de02 \
wwn-0x5000cca22bcb085f \
wwn-0x5000cca23de1a346 \
wwn-0x5000cca23de2a741 \
wwn-0x5000cca26fe4dd64 \
wwn-0x50014ee2ba77e634
  • zpool is one of the primary commands we will use to interact with ZFS.
  • create is a set of sub-commands surrounding creation of a ZFS storage pool.
  • -f simply means to forces use of vdevs, even if they appear in use or specify a conflicting replication level. This can occur if you’ve used a vdev in the past to create a pool but haven’t wiped the drive prior to the zpool create sub-command.
  • tank is the name of your storage pool.
  • -m /tank is the mount point, where the local filesystem can access the ZFS storage pool.
  • draid2 is the ZFS filesystem you want to create. Here I’ve specified the new dRAID filesystem used in ZFS. The 2 part means 2 parity drives and the rest for data with no spares. Later, we’ll be configuring the dRAID filesystem, so hold tight.
  • wwn-0x0000000000000000 is the World Wide Name (WWN) of the hard disk and is unique to that disk. Why this way and not sda, sdb, etc.? Because those names are not guaranteed to point to the same disk on reboot, whereas the WWN is. In my example, I’ve shown 9 disks.

Summary

  • The hardware requirements for a NAS were described in ethernet throughput, hard disk drive rotation speed, and SATA II/III slots via TX2 & expander card on PCI-e Gen2 x4.
  • The basic command to create a ZFS storage pool was presented and parameters explained.

Next Article

Further Resources

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