Master and Slave Proxmox

[openPhiL]

Hi guys,
I found a nice dual mini-itx 19" rack case on Ebay and think, I want to build a proxmox master and slave system where the slave system receives nightly snapshots from the master and could boot those without user interaction.
(why: My home automation is controlling major parts of the house and all familiy members should be able to do a fallback from master to slave.)

Important:. I have 100€/$ budget left.. I want to get this setup working with the components I have.
I have 2 little boards (J5005, J1007u) , 3x2TB, 1x1TB, 1x750GB. the j5005 also has a slot with a 500gb nvme.

Currently, I am running some container and VMs to serve home automation and home network (opensense, openhab, TIG, unifycontroller, nextcloud).

My original Idea was to have a master-system running with 2x2TB drive in Z-Raid1 and another one(slave) with 1x2TB(zfs). Every night, I create and send incremental snapshots to the slave (that i boot up only to receive the new "state" of all machines). I currently have about 500GB of personal data and 100GB on VMs. That slave would then be my backup (with incremental data from multiple days to choose from).
-> that concept worked in my head and virtually (virtualbox), but now I found out that I have SMR drives, so I shouldn't run proxmox with ZFS off those drives. (if you disagree and think that is fine, I am still learning).

So my next strategy is to have master using a 500GB nvme stick to run the vms and use one of the 2TB SMR drive for Data. And the slave has a similiar setup (750GB hdd) plus my second SMR 2TB drive. I could sync those drives now with rsync or so, but that wouldn't be a "backup", it would be a failsafe.

Do you guys have ideas how to squeeze the idea of having at least a couple of days worth of backup in this setup? with 100$ left in my budget?
Thank you!
PhiL

 

[LnxBil]

2x2TB drive in Z-Raid1

You meant mirrored vdev, raidz1 with only two devices has no advantages.

but now I found out that I have SMR drives, so I shouldn't run proxmox with ZFS off those drives. (if you disagree and think that is fine, I am still learning).

There is no technical problem to use these, they are just slow. ZFS send/receive is superior to rsync, so I'd go with your original plan.

 

[openPhiL]

You meant mirrored vdev, raidz1 with only two devices has no advantages.

I think yes I have a rpool that proxmox created during installation.

There is no technical problem to use these, they are just slow. ZFS send/receive is superior to rsync, so I'd go with your original plan.

Thanks for your view. I will go and try my original plan now to see if the performance is ok. I can add the nvme drive as a cache to improve a bit I guess.

 

[LnxBil]

I can add the nvme drive as a cache to improve a bit I guess.

AFAIK, you will not increase send/receive speed with a cache.

 

[openPhiL]

I am running the server with ZFS on my 2TB SMR HDD. A second 2TB SMR HDD will be added as mirror soon, together with a 500GB Nvme for ZIL and ZARC.
Everything is running.. but slow, very slow.. Then I found the sync=disable option. I am still reading through the docs I can find to understand my risk, but I thought this before-after-picture is too impressive to keep for my own.

 

[LnxBil]

Then I found the sync=disable option.

This disables the ZIL.

 

[fabian]

you won't be happy with ZFS and SMR disks.. your test with sync=disabled just tested your in-memory cache, if you benchmark larger I/O sizes, you'll find the performance gets back to abysmal..