May 012021
 
Picture of NVMe Storage Server Project

For over a year and a half I have been working on building a custom NVMe Storage Server for my homelab. I wanted to build a high speed storage system similar to a NAS or SAN, backed with NVMe drives that provides iSCSI, NFS, and SMB Windows File Shares to my network.

The computers accessing the NVMe Storage Server would include VMware ESXi hosts, Raspberry Pi SBCs, and of course Windows Computers and Workstations.

The focus of this project is on high throughput (in the GB/sec) and IOPS.

The current plan for the storage environment is for video editing, as well as VDI VM storage. This can and will change as the project progresses.

The History

More and more businesses are using all-flash NVMe and SSD based storage systems, so I figured there’s no reason why I can’t have build and have my own budget custom all NVMe flash NAS.

This is the story of how I built my own NVMe based Storage Server.

The first version of the NVMe Storage Server consisted of the IO-PEX40152 card with 4 x 2TB Sabrent Rocket 4 NVMe drives inside of an HPE Proliant DL360p Gen8 Server. The server was running ESXi with TrueNAS virtualized, and the PCIe card passed through to the TrueNAS VM.

The results were great, the performance was amazing, and both servers had access to the NFS export via 2 x 10Gb SFP+ networking.

There were three main problems with this setup:

  1. Virtualized – Once a month I had an ESXi PSOD. This was either due to overheating of the IO-PEX40152 card because of modifications I made, or bugs with the DL360p servers and PCIe passthrough.
  2. NFS instead of iSCSI – Because TrueNAS was virtualized inside of the host that was using it for storage, I had to use NFS since the host virtualizing TrueNAS would also be accessing the data on the TrueNAS VM. When shutting down the host, you need to shut down TrueNAS first. NFS disconnects are handled way healthier than iSCSI disconnects (which can cause corruption even if no files are being used).
  3. CPU Cores maxed on data transfer – When doing initial testing, I was maxing out the CPU cores assigned to the TrueNAS VM because the data transfers were so high. I needed a CPU and setup that was better fit.

Version 1 went great, but you can see some things needed to be changed. I decided to go with a dedicated server, not virtualize TrueNAS, and go for a newer CPU with a higher Ghz speed.

And so, version 2 was born (built). Keep reading and scrolling for pictures!

The Hardware

On version 2 of the project, the hardware includes:

Notes on the Hardware:

  • While the ML310e Gen8 v2 server is a cheap low entry server, it’s been a fantastic team member of my homelab.
  • HPE Dual 10G Port 560SFP+ adapters can be found brand new in unsealed boxes on eBay at very attractive prices. Using HPE Parts inside of HPE Servers, avoids the fans from spinning up fast.
  • The ML310e Gen8 v2 has some issues with passing through PCIe cards to ESXi. Works perfect when not passing through.

The new NVMe Storage Server

I decided to repurpose an HPE Proliant ML310e Gen8 v2 Server. This server was originally acting as my Nvidia Grid K1 VDI server, because it supported large PCIe cards. With the addition of my new AMD S7150 x2 hacked in/on to one of my DL360p Gen8’s, I no longer needed the GRID card in this server and decided to repurpose it.

Picture of an HPe ML310e Gen8 v2 with NVMe Storage
HPe ML310e Gen8 v2 with NVMe Storage

I installed the IOCREST IO-PEX40152 card in to the PCIe 16x slot, with 4 x 2TB Sabrent Rocket 4 NVME drives.

Picture of IOCREST IO-PEX40152 with GLOTRENDS M.2 NVMe SSD Heatsink on Sabrent Rocket 4 NVME
IOCREST IO-PEX40152 with GLOTRENDS M.2 NVMe SSD Heatsink on Sabrent Rocket 4 NVME

While the server has a PCIe 16x wide slot, it only has an 8x bus going to the slot. This means we will have half the capable speed vs the true 16x slot. This however does not pose a problem because we’ll be maxing out the 10Gb NICs long before we max out the 8x bus speed.

I also installed an HPE Dual Port 560SFP+ NIC in to the second slot. This will allow a total of 2 x 10Gb network connections from the server to the Ubiquiti UniFi US-16-XG 10Gb network switch, the backbone of my network.

The Server also have 4 x Hot Swappable HD bays on the front. When configured in HBA mode (via the BIOS), these are accessible by TrueNAS and can be used. I plan on populating these with 4 x 4TB HPE MDL SATA Hot Swappable drives to act as a replication destination for the NVMe pool and/or slower magnetic long-term storage.

Front view of HPE ML310e Gen8 v2 with Hotswap Drive bays
HPE ML310e Gen8 v2 with Hotswap Drive bays

I may also try to give WD RED Pro drives a try, but I’m not sure if they will cause the fans to speed up on the server.

TrueNAS Installation and Configuration

For the initial Proof-Of-Concept for version 2, I decided to be quick and dirty and install it to a USB stick. I also waited until I installed TrueNAS on to the USB stick and completed basic configuration before installing the Quad NVMe PCIe card and 10Gb NIC. I’m using a USB 3.0 port on the back of the server for speed, as I can’t verify if the port on the motherboard is USB 2 or USB 3.

Picture of a TrueNAS USB Stick on HPE ML310e Gen8 v2
TrueNAS USB Stick on HPE ML310e Gen8 v2

TrueNAS installation worked without any problems whatsoever on the ML310e. I configured the basic IP, time, accounts, and other generic settings. I then proceeded to install the PCIe cards (storage and networking).

Screenshot of TrueNAS Dashboard Installed on NVMe Storage Server
TrueNAS Installed on NVMe Storage Server

All NVMe drives were recognized, along with the 2 HDDs I had in the front Hot-swap bays (sitting on an HP B120i Controller configured in HBA mode).

Screenshot of available TrueNAS NVMe Disks
TrueNAS NVMe Disks

The 560SFP+ NIC also was detected without any issues and available to configure.

Dashboard Screenshot of TrueNAS 560SFP+ 10Gb NIC
TrueNAS 560SFP+ 10Gb NIC

Storage Configuration

I’ve already done some testing and created a guide on FreeNAS and TrueNAS ZFS Optimizations and Considerations for SSD and NVMe, so I made sure to use what I learned in this version of the project.

I created a striped pool (no redundancy) of all 4 x 2TB NVMe drives. This gave us around 8TB of usable high speed NVMe storage. I also created some datasets and a zVOL for iSCSI.

Screenshot of NVMe TrueNAS Storage Pool with Datasets and zVol
NVMe TrueNAS Storage Pool with Datasets and zVol

I chose to go with the defaults for compression to start with. I will be testing throughput and achievable speeds in the future. You should always test this in every and all custom environments as the results will always vary.

Network Configuration

Initial configuration was done via the 1Gb NIC connection to my main LAN network. I had to change this as the 10Gb NIC will be directly connected to the network backbone and needs to access the LAN and Storage VLANs.

I went ahead and configured a VLAN Interface on VLAN 220 for the Storage network. Connections for iSCSI and NFS will be made on this network as all my ESXi servers have vmknics configured on this VLAN for storage. I also made sure to configure an MTU of 9000 for jumbo frames (packets) to increase performance. Remember that all hosts must have the same MTU to communicate.

Screenshot of 10Gb NIC on Storage VLAN
10Gb NIC on Storage VLAN

Next up, I had to create another VLAN interface for the LAN network. This would be used for management, as well as to provide Windows File Share (SMB/Samba) access to the workstations on the network. We leave the MTU on this adapter as 1500 since that’s what my LAN network is using.

Screenshot of 10Gb NIC on LAN VLAN
10Gb NIC on LAN VLAN

As a note, I had to delete the configuration for the existing management settings (don’t worry, it doesn’t take effect until you hit test) and configure the VLAN interface for my LANs VLAN and IP. I tested the settings, confirmed it was good, and it was all setup.

At this point, only the 10Gb NIC is now being used so I went ahead and disconnected the 1Gb network cable.

Sharing Setup and Configuration

It’s now time to configure the sharing protocols that will be used. As mentioned before, I plan on deploying iSCSI, NFS, and Windows File Shares (SMB/Samba).

iSCSI and NFS Configuration

Normally, for a VMware ESXi virtualization environment, I would always usually prefer iSCSI based storage, however I also wanted to configure NFS to test throughput of both with NVMe flash storage.

Earlier, I created the datasets for all my my NFS exports and a zVOL volume for iSCSI.

Note, that in order to take advantage of the VMware VAAI storage directives (enhancements), you must use a zVOL to present an iSCSI target to an ESXi host.

For NFS, you can simply create a dataset and then export it.

For iSCSI, you need to create a zVol and then configure the iSCSI Target settings and make it available.

SMB (Windows File Shares)

I needed to create a Windows File Share for file based storage from Windows computers. I plan on using the Windows File Share for high-speed storage of files for video editing.

Using the dataset I created earlier, I configured a Windows Share, user accounts, and tested accessing it. Works perfect!

Connecting the host

Connecting the ESXi hosts to the iSCSI targets and the NFS exports is done in the exact same way that you would with any other storage system, so I won’t be including details on that in this post.

We can clearly see the iSCSI target and NFS exports on the ESXi host.

Screenshot of TrueNAS NVMe iSCSI Target on VMware ESXi Host
TrueNAS NVMe iSCSI Target on VMware ESXi Host
Screenshot of NVMe iSCSI and NFS ESXi Datastores
NVMe iSCSI and NFS ESXi Datastores

To access Windows File Shares, we log on and map the network share like you would normally with any file server.

Testing

For testing, I moved (using Storage vMotion) my main VDI desktop to the new NVMe based iSCSI Target LUN on the NVMe Storage Server. After testing iSCSI, I then used Storage vMotion again to move it to the NFS datastore. Please see below for the NVMe storage server speed test results.

Speed Tests

Just to start off, I want to post a screenshot of a few previous benchmarks I compiled when testing and reviewing the Sabrent Rocket 4 NVMe SSD disks installed in my HPE DL360p Gen8 Server and passed through to a VM (Add NVMe capability to an HPE Proliant DL360p Gen8 Server).

Screenshot of CrystalDiskMark testing an IOCREST IO-PEX40152 and Sabrent Rocket 4 NVME SSD for speed
CrystalDiskMark testing an IOCREST IO-PEX40152 and Sabrent Rocket 4 NVME SSD
Screenshot of CrystalDiskMark testing IOPS on an IOCREST IO-PEX40152 and Sabrent Rocket 4 NVME SSD
CrystalDiskMark testing IOPS on an IOCREST IO-PEX40152 and Sabrent Rocket 4 NVME SSD

Note, that when I performed these tests, my CPU was maxed out and limiting the actual throughput. Even then, these are some fairly impressive speeds. Also, these tests were directly testing each NVMe drive individually.

Moving on to the NVMe Storage Server, I decided to test iSCSI NVMe throughput and NFS NVMe throughput.

I opened up CrystalDiskMark and started a generic test, running a 16GB test file a total of 6 times on my VDI VM sitting on the iSCSI NVMe LUN.

Screenshot of NVMe Storage Server iSCSI Benchmark with CrystalDiskMark
NVMe Storage Server iSCSI Benchmark with CrystalDiskMark

You can see some impressive speeds maxing out the 10Gb NIC with crazy performance of the NVME storage:

  • 1196MB/sec READ
  • 1145.28MB/sec WRITE (Maxing out the 10GB NIC)
  • 62,725.10 IOPS READ
  • 42,203.13 IOPS WRITE

Additionally, here’s a screenshot of the ix0 NIC on the TrueNAS system during the speed test benchmark: 1.12 GiB/s.

Screenshot of TrueNAS NVME Maxing out 10Gig NIC
TrueNAS NVME Maxing out 10Gig NIC

And remember this is with compression. I’m really excited to see how I can further tweak and optimize this, and also what increases will come with configuring iSCSI MPIO. I’m also going to try to increase the IOPS to get them closer to what each individual NVMe drive can do.

Now on to NFS, the results were horrible when moving the VM to the NFS Export.

Screenshot of NVMe Storage Server NFS Benchmark with CrystalDiskMark
NVMe Storage Server NFS Benchmark with CrystalDiskMark

You can see that the read speed was impressive, but the write speed was not. This is partly due to how writes are handled with NFS exports.

Clearly iSCSI is the best performing method for ESXi host connectivity to a TrueNAS based NVMe Storage Server. This works perfect because we’ll get the VAAI features (like being able to reclaim space).

Moving Forward

I’ve had this configuration running for around a week now with absolutely no issues, no crashes, and it’s been very stable.

Using a VDI VM on NVMe backed storage is lightning fast and I love the experience.

I plan on running like this for a little while to continue to test the stability of the environment before making more changes and expanding the configuration and usage.

Future Plans (and Configuration)

  • Drive Bays
    • I plan to populate the 4 hot-swappable drive bays with HPE 4TB MDL drives. Configured with RaidZ1, this should give me around 12TB usable storage. I can use this for file storage, backups, replication, and more.
  • NVMe Replication
    • This design was focused on creating non-redundant extremely fast storage. Because I’m limited to a total of 4 NVMe disks in this design, I chose not to use RaidZ and striped the data. If one NVMe drive is lost, all data is lost.
    • I don’t plan on storing anything important, and at this point the storage is only being used for VDI VMs (which are backed up), and Video editing.
    • If I can populate the front drive bays, I can replicate the NVMe storage to the traditional HDD storage on a frequent basis to protect against failure to some level or degree.
  • Version 3 of the NVMe Storage Server
    • More NVMe and Bigger NVMe – I want more storage! I want to test different levels of RaidZ, and connect to the backbone at even faster speeds.
    • NVME Drives with PLP (Power Loss Prevention) for data security and protection.
    • Dual Power Supply

Let me know your thoughts and ideas on this setup!

Jun 062020
 
Screenshot of NVMe SSD on FreeNAS

Looking at using SSD and NVMe with your FreeNAS or TrueNAS setup and ZFS? There’s considerations and optimizations that must be factored in to make sure you’re not wasting all that sweet performance. In this post I’ll be providing you with my own FreeNAS and TrueNAS ZFS optimizations for SSD and NVMe to create an NVMe Storage Server.

This post will contain observations and tweaks I’ve discovered during testing and production of a FreeNAS ZFS pool sitting on NVMe vdevs, which I have since upgraded to TrueNAS Core. I will update it with more information as I use and test the array more.

Screenshot of FreeNAS ZFS NVMe SSD Pool with multiple datasets
FreeNAS/TrueNAS ZFS NVMe SSD Pool with multiple datasets

Considerations

It’s important to note that while your SSD and/or NVMe ZFS pool technically could reach insane speeds, you will probably always be limited by the network access speeds.

With this in mind, to optimize your ZFS SSD and/or NVMe pool, you may be trading off features and functionality to max out your drives. These optimizations may in fact be wasted if you reach the network speed bottleneck.

Some feature you may be giving up may actually help extend the life or endurance of your SSD such as compression and deduplication, as they reduce the number of writes performed on each of your vdevs (drives).

You may wish to skip these optimizations should your network be the limiting factor, which will allow you to utilize these features with no performance or minimal performance degradation to the final client. You should measure your network throughput to establish the baseline of your network bottleneck.

Deploying SSD and NVMe with FreeNAS or TrueNAS

For reference, the environment I deployed FreeNAS with NVMe SSD consists of:

Update (May 1st, 2021): Since this blog post was created, I have since used what was learned in my new NVMe Storage Server Project. Make sure you check it out after reading this post!

As mentioned above, FreeNAS is virtualizatized on one of the HPE DL360 Proliant servers and has 8 CPUs and 32GB of RAM. The NVME are provided by VMware ESXi as PCI passthrough devices. There has been no issues with stability in the months I’ve had this solution deployed. It is also still working amazing since upgrading FreeNAS to TrueNAS core.

Screenshot of Sabrent Rocket 4 2TB NVMe SSD on FreeNAS
Sabrent Rocket 4 2TB NVMe SSD on FreeNAS

Important notes:

  • VMXNET3 NIC is used on VMs to achieve 10Gb networking
  • Using PCI passthrough, snapshots on FreeNAS VM are disabled (this is fine)
  • NFS VM datastore is used for testing as the host running the FreeNAS VM has the NFS datastore store mounted on itself.

There are a number of considerations that must be factored in when virtualization FreeNAS and TrueNAS however those are beyond the scope of this blog post. I will be creating a separate post for this in the future.

Use Case (Fast and Risky or Slow and Secure)

The use case of your setup will depict which optimizations you can use as some of the optimizations in this post will increase the risk of data loss (such as disabled sync writes and RAIDz levels).

Fast and Risky

Since SSDs are more reliable and less likely to fail, if you’re using the SSD storage as temporary hot storage, you could simply using striping to stripe across multiple vdevs (devices). If a failure occurred, the data would be lost, however if you’re were just using this for “staging” or using hot data and the risk was acceptable, this is an option to drastically increase speeds.

Example use case for fast and risky

  • VDI Pool for clones
  • VMs that can be restored easily from snapshots
  • Video Editing
  • Temporary high speed data dump storage

The risk can be lowered by replicating the pool or dataset to slower storage on a frequent or regular basis.

Slow and Secure

Using RAIDz-1 or higher will allow for vdev (drive) failures, but with each level increase, performance will be lost due to parity calculations.

Example use case for slow and secure

  • Regular storage for all VMs
  • Database (SQL)
  • Exchange
  • Main storage

Slow and Secure storage is the type of storage found in most applications used for SAN or NAS storage.

SSD Endurance and Lifetime

Solid state drives have a lifetime that’s typically measured in lifetime writes. If you’re storing sensitive data, you should plan ahead to mitigate the risk of failure when the drive reaches it’s full lifetime.

Steps to mitigate failures

  • Before putting the stripe or RAIDz pool in to production, perform some large bogus writes and stagger the amount of data written on the SSDs individually. While this will reduce the life counter on the SSDs, it’ll help you offset and stagger the lifetime of each drives so they don’t die at the same time.
  • If using RAIDz-1 or higher, preemptively replace the SSD before the lifetime is hit. Do this well in advance and stagger it to further create a different between the lifetime of each drive.

Decommissioning the drives preemptively and early doesn’t mean you have to throw them away, this is just to secure the data on the ZFS pool. You can can continue to use these drives in other systems with non-critical data, and possibly use the drive well beyond it’s recommended lifetime.

Compression and Deduplication

Using compression and deduplication with ZFS is CPU intensive (and RAM intensive for deduplication).

The CPU usage is negligible when using these features on traditional magnetic storage (traditional magentic platter hard drive storage) because when using traditional hard drives, the drives are the performance bottleneck.

SSD are a total different thing, specifically with NVMe. With storage speeds in the gigabytes per second, CPUs cannot keep up with the deduplication and compression of data being written and become the bottleneck.

I performed a simple test comparing speeds with compression and dedupe with the same VM running CrystalDiskMark on an NFS VMware datastore running over 10Gb networking. The VM was configured with a single drive on a VMware NVME controller.

NVMe SSD with compression and deduplication

Screenshot of benchmark of CrystalDiskMark on FreeNAS NFS SSD datastore with compression and deduplication
CrystalDiskMark on FreeNAS NFS SSD datastore with compression and deduplication

NVMe SSD with deduplication only

Screenshot of benchmark of CrystalDiskMark on FreeNAS NFS SSD datastore with deduplication only
CrystalDiskMark on FreeNAS NFS SSD datastore with deduplication only

NVMe SSD with compression only

Screenshot of benchmark of CrystalDiskMark on FreeNAS NFS SSD datastore with compression only
CrystalDiskMark on FreeNAS NFS SSD datastore with compression only

Now this is really interesting, that we actually see a massive speed increase with compression only. This is because I have a server class CPU with multiple cores and a ton of RAM. With lower performing specs, you may notice a decrease in performance.

NVMe SSD without compression and deduplication

Screenshot of benchmark with CrystalDiskMark on FreeNAS NFS SSD datastore without compression and deduplication
CrystalDiskMark on FreeNAS NFS SSD datastore without compression and deduplication

In my case, the 10Gb networking was the bottleneck on read operations as there was virtually no change. It was a different story for write operations as you can see there is a drastic change in write speeds. Write speeds are greatly increased when writes aren’t being compressed or deduped.

Note that on faster networks, read speeds could and will be affected.

If your network connection to the client application is the limiting factor and the system can keep up with that bottleneck then you will be able to get away with using these features.

Higher throughput with compression and deduplication can be reached with higher frequency CPUs (more Ghz), more cores (for more client connections). Remember that large amounts of RAM are required for deduplication.

Using compression and deduplication may also reduce the writes to your SSD vdevs, prolonging the lifetime and reducing the cost of maintaining the solution.

ZFS ZIL and SLOG

When it comes to writes on a filesystem, there a different kinds.

  • Synchronous – Writes that are made to a filesystem that are only marked as completed and successful once it has actually been written to the physical media.
  • Asynchronous – Writes that are made to a filesystem that are marked as completed or successful before the write has actually been completed and committed to the physical media.

The type of write performed can be requested by the application or service that’s performing the write, or it can be explicitly set on the file system itself. In FreeNAS (in our example) you can override this by setting the “sync” option on the zpool, dataset, or zvol.

Disabling sync will allow writes to be marked as completed before they actually are, essentially “caching” writes in a buffer in memory. See below for “Ram Caching and Sync Writes”. Setting this to “standard” will perform the type of write requested by the client, and setting to “always” will result in all writes being synchronous.

We can speed up and assist writes by using a SLOG for ZIL.

ZIL stands for ZFS Intent Log, and SLOG standards for Separated Log which is usually stored on a dedicated SLOG device.

By utilizing a SLOG for ZIL, you can have dedicated SSDs which will act as your intent log for writes to the zpool. On writes that request a synchronous write, they will be marked as completed when sent to the ZIL and written to the SLOG device.

Implementing a SLOG that is slower than the combined speed of your ZFS pool will result in a performance loss. You SLOG should be faster than the pool it’s acting as a ZIL for.

Implementing a SLOG that is faster than the combined speed of your ZFS pool will result in a performance gain on writes, as it essentially act as “write cache” for synchronous writes and will possibly even perform more orderly writes when it commits it to the actual vdevs in the pool.

If using a SLOG for ZIL, it is highly recommend to use an SSD that has PLP (power loss protection) as well as a mirrored set to avoid data loss and/or corruption in the event of a power loss, crash, or freeze.

RAM Caching and Sync Writes

In the event you do not have a SLOG device to provide a ZIL to your zpool, and you have a substantial amount of memory, you can disable sync writes on the pool which will drastically increase write operations as they will be buffered in RAM memory.

Disabling sync on your zpool, dataset, or zvol, will tell the client application that all writes has been complete and committed to disk (HD or SSD) before it has actually done so. This allows the system to cache writes in the system memory.

In the event of a power loss, crash, or freeze, this data will be lost and/or possibly result in corruption.

You would only want to do this if you had the need for fast storage where data loss would is acceptable (such as video editing, a VDI clone desktop pool, etc).

Utilizing a SLOG for ZIL is much better (and safer) then this method, however I still wanted to provide this for informational purposes as it does apply to some use cases.

SSD Sector Size

Traditional drives typically used 512k physical sector sizes. Newer hard drives and SSDs use 4k sectors, but often emulate 512k logical sectors (called 512e) for compatibility. SSD’s specifically sometimes ship with 512e to increase compatibility with operating systems and the ability to clone your old drive to the new SSD during migrations.

When emulating 512k logical sectors on an HD or SSD that uses 4k physical native sectors, an operation that writes 4k will result in 4 operations instead of 1. This increases overhead and could result in reduced IO and speed, as well as create more wear on the SSD when performing writes.

Some HDs and SSDs come with utilities or tools to change the sector size of the drive. I highly recommend changing it to it’s native sector size.

iSCSI vs NFS

Technically faster speeds should possible using iSCSI instead of NFS, however special care must be made when using iSCSI.

If you’re using iSCSI and the host that is virtualizing the FreeNAS instance is also mounting the iSCSI VMFS target that it’s presenting, you must unmount this iSCSI volume every time you go plan to shut down the FreeNAS instance, or the entire host that is hosting it. Unmounting the iSCSI datastore also means unregistering any VMs that reside on it.

Screenshot of VMware ESXi with FreeNAS NVMe SSD as NFS datastore
VMware ESXi with virtualized FreeNAS as NFS datastore

If you simply shutdown the FreeNAS instance that’s hosting the iSCSI datastore, this will result in a improper unclean unmount of the VMFS volume and could lead to data loss, even if no VMs are running.

NFS provides a cleaner mechanism, as the FreeNAS handles the unmount of the base filesystem cleanly on shutdown and to the ESXi hosts it appears as an NFS disconnect. If VMs are not running (and no I/O is occuring) when the FreeNAS instance is shut down, data loss is not a concern.

Jumbo Frames

Since you’re pushing more data, more I/O, and at a faster pace, we need to optimize all layers of the solution as much as possible. To reduce overhead on the networking side of things, if possible, you should implement jumbo frames.

Instead of sending many smaller packets which independently require acknowledgement, you can send fewer larger packets. This significantly reduces overhead and allows for faster speed.

In my case, my FreeNAS instance will be providing both NAS and SAN services to the network, thus has 2 virtual NICs. On my internal LAN where it’s acting as a NAS (NIC 1), it will be using the default MTU of 1500 byte frames to make sure it can communicate with workstations that are accessing the shares. On my SAN network (NIC 2) where it will be acting as a SAN, it will have a configured MTU of 9000 byte frames. All other devices (SANs, client NICs, and iSCSI initiators) on the SAN network have a matching MTU of 9000.

Additional Notes

Please note that consumer SSDs usually do not have PLP (Power Loss Prevention). This means that in the event of a power failure, any data sitting on the write cache on the SSD may be lost. This could put your data at risk. Using enterprise solid state drives remedies this issue as they often come with PLP.

Conclusion

SSD’s are great for storage, whether it be file, block, NFS, or iSCSI! It’s in my opinion that NVMe and all flash arrays is where the future of storage is going.

I hope this information helps, and if you feel I left anything out, or if anything needs to be corrected, please don’t hesitate to leave a comment!