New TrueNAS Server - Question re Cloning / Imaging / Backup

[AntoninKyrene]

Hello again!

So...I have a design for our fourth server deployment. Another Fractal Design Define 7 XL with an AMD PRO APU and 64GB of ECC RAM. Two based upon this basic design are currently running without issue and have been for several months now. I have 12x 3TB Red Pro drives and 4x 4TB Red Pro drives for this build, and the usual IBM M5110 controllers x2. This is essentially a clone of the server discussed here previously.

Two questions:

1) This server and the second server, being almost identical, would make a great 'heartbeat' setup, where one server is continuously backing up / mirroring the other, so if one fails, the other is essentially a hot spare, ready for immediate takeover of duties. I use the term 'heartbeat' as this is what Synology calls their version of this process, and it's what I am familiar with. I'm actually not doing this right now, but I should be. Does TrueNAS support this? (This would be a local setup within the same residence...)

2) The third server - not previously discussed here - is lacking an external / off-site backup. For now, the best I can do is copy the data to external drives every so often. The data on this server is archival and rarely changes. Most of the incremental differences are the addition of new data. There are four pools: 16TB, 12TB, 12TB and 8TB. For each I have an external USB drive with a capacity 2TB greater than the pool. Does TrueNAS support backing up these pools to external USB devices on an incremental basis? And yes, I know USB is not ideal, but it would work for now.

All of this will eventually be replaced by a data-center-worthy solution that includes off-site storage with a continuous data connection, but for now, this Astonishing Achievement in Redneck Engineering must suffice. (The last award being received for a 'we will pay you to dispose of this stuff!" Xserve configuration that required nuclear-powered air cooling...)

Thank you!

 

[AntoninKyrene]

I think I found the answer to the USB question...

 

[NugentS]

There is no heartbeat instant replication between servers to keep one identical to the other. The best you can currently do is set up a snapshot and replication session that runs every 5 minutes or so. You do run a risk of what happens if you make a big change and the replication hasn't finished, but the process kicks off another one. If that happens several times in a row you may have a problem - I don't know

Scale was intended to have this feature using gluster but that has, ahh, died. I think IX are exploring other options

 

[AntoninKyrene]

Thank you for your response! What you have suggested should work, as the data arrives for storage once every 24 hours, if new data is generated during the daily workflow, and almost never exceeds 50GB.

 

[NugentS]

As to USB. Yes it can work but with caveats:
1. 1 Disk to 1 Pool of USB devices - don't try multiple disk vdevs or multiple vdev pools on USB
2. Don't stick a USB Hub on a USB Port and expect to run multiple USB disks from the HUB

@Arwen has experience of using USB as backup destinations

 

[AntoninKyrene]

We have a SiiG 4-Port USB 3.0 PCIe card, with each port having a dedicated 5Gbps lane/channel (theoretical bandwidth for the card is 20Gbps) which runs on a PCIe 2.0 x4 slot. I haven't done the math yet, but I know to implement it, we will have to either upgrade the mainboard to gain a third > x1 PCIe slot, as both non-x1 slots are occupied by the controllers, or replace the controllers with the 16-port version of the same family. 16 ports on one card = reduction in bandwidth to each drive - probably, or maybe not, as they are HDDs - but for the purpose of these servers that's really not a problem.

OR, as suggested locally, we could install an M.2-to-PCIe adapter (if such a thing exists) or maybe the U.2 kit and adapt from there. One of the M.2 slots supports 4 lanes AND the TrueNAS SSD is on the M.2 slot with the 2-lane interface, so this is a 'maybe' option...

 

[Ericloewe]

M.2-to-PCIe adapter (if such a thing exists)

Of course. I don't understand why they're so popular and available, given the terrible positioning of most M.2 slots (for a while motherboards even had them on the back side of the PCB!), but they do exist in a variety of flavors.