One little step bigger than the Odroid HC2 - what to choose?

budpad · 11. Februar 2019

Hi,

I'm new to OMV and had a bit of trouble while installing - but now it works quite well and I'm really convinced.

I'm using it with an Odroid HC2 with System on SD-Card and a WD Red 4TB.

Everything fine - and I will stay with this system as a backup-system.

My main-system should be a little big better/bigger system at all.

I want to use the main system as a OMV-NAS and with 1-2 running dockers (Nextcloud + one more).

That would stress my little Odroid HC2 with it's SD-Card too much. So what would be the advice to go one step bigger? Don't wanna waste too much power / energy.

Really looking forward for a few advices.

Thx Bud

KM0201 · 11. Februar 2019

Well... If you like the hc2... You could buy/build 2 more. One to run nextxloud, and the other to do whatever else you want.

tkaiser · 11. Februar 2019

Zitat von budpad

I want to use the main system as a OMV-NAS and with 1-2 running dockers (Nextcloud + one more).

That would stress my little Odroid HC2 with it's SD-Card too much

Why?

Your HC2 is overpowered for such tasks anyway and you can push the docker container storage to either your HDD or you attach an SSD in a JMS578 or ASM1153 enclosure to the USB port and run the stuff there. While everybody will be telling you that's just USB2 and too slow that's not true. Random IO performance is important and a SSD in an USB2 attached enclosure should easily outperform a HDD attached to USB3 (that's the HC2's 'SATA port', everything is USB here).

budpad · 11. Februar 2019

Zitat von tkaiser

Why?
Your HC2 is overpowered for such tasks anyway and you can push the docker container storage to either your HDD or you attach an SSD in a JMS578 or ASM1153 enclosure to the USB port and run the stuff there. While everybody will be telling you that's just USB2 and too slow that's not true. Random IO performance is important and a SSD in an USB2 attached enclosure should easily outperform a HDD attached to USB3 (that's the HC2's 'SATA port', everything is USB here).

It's not because of the OC2-Power overall... I thought, that it stresses the SD-Card from my HC2 too much? I'm a little bit afraid if the SD-Card will last long enough. Especially if I will run a Nextcloud-instance > or does the Docker (Nextcloud) read/write only to the storage I will attach?

tkaiser · 11. Februar 2019

Zitat von budpad

I'm a little bit afraid if the SD-Card will last long enough. Especially if I will run a Nextcloud-instance > or does the Docker (Nextcloud) read/write only to the storage I will attach?

AFAIK you can store the whole container somewhere else than the rootfs (SD card). So either on the HDD that's already there or on an USB2 attached SSD (every SSD even when just attached via USB2 will always outperform the fastest HDD available with these workloads since random IO / IOPS are way more important than MB/s).

Check the IOPS values here: https://forum.armbian.com/topi…findComment&comment=51350 -- even the most lousy hardware OMV can run on (Raspberry Pi 2) shows +2000 IOPS in undervolted mode (limiting CPU cores to 600 MHz). You'll have a hard time to find a HDD exceeding 200 IOPS so SSD is at least 10 times faster even if bottlenecked by USB2.

budpad · 11. Februar 2019

I'm totally with you. USB and an SSD would be totally ok for that scenario.

But I don't know if it's ok for my system-SD-Card at all - can I somehow find out how much the SD-card is/will be stressed?

And another question:
2 x USB-Disks at the 1 x USB-Port of the HC2 via Hub is also ok? Would be one SSD for the nextcloud-docker and one for a backup HDD.

tkaiser · 11. Februar 2019

Zitat von budpad

can I somehow find out how much the SD-card is/will be stressed?

On all the (Armbian based) OMV images for ARM devices it's rather easy since I added monitoring functionality for exactly this reason. The problem is the so called 'Write Amplification' being rather high when not special precautions are taken. You can watch what happens in real-time.

The following example is from an EspressoBin running off /dev/sdb (USB thumbdrive):

Code

root@espressobin:~# cat /proc/partitions 
major minor  #blocks  name


   1        0      48000 ram0
  31        0       1536 mtdblock0
  31        1         64 mtdblock1
  31        2       2496 mtdblock2
   8        0  488386584 sda
   8        1  488385543 sda1
   8       16  121307136 sdb
   8       17    7745904 sdb1
   8       18  112344063 sdb2
 253        0      51200 zram0
 253        1     254172 zram1
 253        2     254172 zram2
root@espressobin:~# armbianmonitor -d sdb
Mon Feb 11 14:00:52 CET 2019       3/2636 pages written after 26 sec
Mon Feb 11 14:13:49 CET 2019       2/3093508 pages written after 777 sec
Mon Feb 11 14:14:19 CET 2019       1/137004 pages written after 30 sec
Mon Feb 11 14:17:02 CET 2019       1/533716 pages written after 163 sec
Mon Feb 11 14:27:28 CET 2019       2/1116492 pages written after 626 sec
Mon Feb 11 14:27:59 CET 2019       3/20 pages written after 31 sec
^C

Alles anzeigen

And this is a NanoPi M1 Plus running off /dev/mmcblk1 (eMMC):

Code

root@monit:~# armbianmonitor -d mmcblk1
Mon Feb 11 14:19:03 CET 2019      43/176 pages written after 4 sec
Mon Feb 11 14:19:08 CET 2019      66/284 pages written after 5 sec
Mon Feb 11 14:19:22 CET 2019      43/184 pages written after 14 sec
Mon Feb 11 14:19:32 CET 2019      43/176 pages written after 10 sec
Mon Feb 11 14:19:44 CET 2019      43/188 pages written after 12 sec
Mon Feb 11 14:19:54 CET 2019      43/176 pages written after 10 sec
Mon Feb 11 14:20:06 CET 2019      43/176 pages written after 11 sec
Mon Feb 11 14:20:16 CET 2019      87/360 pages written after 11 sec
Mon Feb 11 14:20:27 CET 2019      43/176 pages written after 11 sec
Mon Feb 11 14:20:38 CET 2019      43/176 pages written after 11 sec
Mon Feb 11 14:20:49 CET 2019      43/176 pages written after 11 sec
Mon Feb 11 14:21:00 CET 2019      43/176 pages written after 11 sec
Mon Feb 11 14:21:11 CET 2019      66/268 pages written after 11 sec
Mon Feb 11 14:21:21 CET 2019      43/176 pages written after 10 sec
Mon Feb 11 14:21:33 CET 2019      43/176 pages written after 12 sec
Mon Feb 11 14:21:43 CET 2019      43/176 pages written after 10 sec
Mon Feb 11 14:21:55 CET 2019      43/176 pages written after 12 sec
Mon Feb 11 14:22:05 CET 2019      66/268 pages written after 10 sec
^C

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So you can see easily that on the EspressoBin storage write access happens only from time to time while on the NanoPi every 10 seconds stuff gets written. Which is bad since small writes every now and then result in high Write Amplification. This host runs a monitoring instance updating all its RRD (round robin databases) every 10 seconds. We will change this soon since with this write pattern the eMMC will wear out pretty fast.

TL;DR: Check the device node your rootfs (SD card) is using and monitor yourself using armbianmonitor -d

Wrt USB hubs I made that much negative experiences that at least I try to avoid them whenever possible. But YMMV as usual.

Adoby · 14. Februar 2019

It is not very difficult to install OMV on a HC2 so that the root filesystem is on the hdd. It may have implications regarding performance, safety and backups and so on. But it should be mostly OK.

For instance you can have /boot on the SD card, / (root fs) on sda1 and /sharedfolders on sda2

You need to manually create sda1 (btrfs) and sda2 (ext4). I boot a fresh install on a card and use ssh, parted and mkfs.ext4 to format sda2.

Then run nand-sata-install.sh. It will format (btrfs) sda1 and move the rootfs to sda1.

Reboot. Will boot from /boot on the card, but the root fs is now on sda1.

Mount sda2 in OMV and proceed to create shared folders on /dev/sda2. And carry on as usual.

I'm experimenting with a OMV HC1 with a firecuda sshd drive, that has / on the firecuda. Works fine. Hdd has 5 year warranty. Will test to run Emby and NextCloud on it. At least. Will be a birthday gift for a relative in March. Emby is running fine.

I also have had an Armbian HC2 with a ssd with / on the ssd for a while now. Works fine.

If you have several HC2 you can even put /var/lib/docker on another HC2 and mount it over nfs. Perhaps using some type of auto mount (not OMV). I haven't tried that yet.

Also it might be possible to use a couple of HC2 as a docker swarm. I haven't tried that either. Yet.

Jetzt mitmachen!