AALONDON

[First NAS project - 10Gbps - RAID 10] Looking for advice and recommendations.

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Hello, community!

Thank you in advance for your interest

I'm new in this environment, I knew a part of the basic knowledge of xpenology.

 

What I have in mind :

Build a NAS powerful, more than 2gb/s. 10Gbps and Raid 10 for safety.

So, I have thought about 12 IronWolf 4TB.

Also, some SSD for cache (I really don't want a slow NAS).

 

My first's questions :

  • Can be possible to use my future NAS xpenology like a DAS too? 
  • What MB will I need? (With how many SATA ports? Because I don't really know how PCI controllers are working)

 

Will be awesome if you have some hardware in mind. Thank you for you're helping.

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On 9/15/2018 at 1:09 AM, AALONDON said:

Build a NAS powerful, more than 2gb/s. 10Gbps and Raid 10 for safety.

 

10G for sure but raid6 might give you enough speed and more space to use, if assembled you can try by installing dsm and creating/deleting the data volume in different raid configurations, you can expect 400-500 /MB/s from, also keep in mind even if you can read with 900 MB/s most disks (even ssd's with sata interface) cant handle that speed, you might be able to measure it with same network tools but ...

raid10 for safty? there is no replacement for backup, more important data results in more frequent backup (and/or storing backups in a different location where burglar or fire cant harm them)

 

On 9/15/2018 at 1:09 AM, AALONDON said:

So, I have thought about 12 IronWolf 4TB.

 

you might reconsider this, sata ports and energy also cost money, 8 or 10TB disks and less ports might cost the same and give you more room to expand (usually you will have such system for 3-6 years), so compare the price $ per TB and plan to double your capacity after 2 years (witch is much cheaper if you can add disks instead of replacing 12 disks)

 

 

On 9/15/2018 at 1:09 AM, AALONDON said:

Also, some SSD for cache (I really don't want a slow NAS).

 

ssd's for reading will only speed up things if they are already in ssd cache, so mostly on systems where many users access data, a system used by one user will not see much gain from a read cache

for writing cache dsm will need two ssd's (running internal as raid1), also here its important to have a closer look, to achieve faster write your source where the data comes from hast to be fast enough, a normal sata ssd will max out with 600MB/s so you would need nvme ssd on both ends to max out 10G network (btw there is also 40G available ...), for using nvme you will need the 918+ image (baremetal install)

 

my system has 12 ports, 11 x 4TB disks (stated with 6), no ssd cache, nvme ssd on client side

there might be some special cases like video editing where big files are often written but if its for a single person local storage for editing and nas (10G nic, 500MB/s) storage/archive is more cost effective and gives better speed and latency

 

On 9/15/2018 at 1:09 AM, AALONDON said:
  • Can be possible to use my future NAS xpenology like a DAS too? 

 

depends on the software and how you implement the nas

you can use iSCSI for disk replacement if a software does not want to write to a network drive but in that case its called SAN and latency and I/O per second gets more important (like using fiber instead of 10GBaseT)

so basically yes, with iSCSI you can do it

 

 

On 9/15/2018 at 1:09 AM, AALONDON said:
  • What MB will I need? (With how many SATA ports? Because I don't really know how PCI controllers are working)

 

if you are that kind of hardware beginner then you might start with a smaller project or let someone with more experience assist you (not just some people over the internet, more a friend with hands on capabilitys)

keep in mind that the default xpenology config (kicking in after a bigger update) is 12 disks, if you user 12 data disks and 2 ssd's for cache you will be at 14 ports and loose something after a backup (back to 12 ports) and will have to restore config manually - nothing for beginners and people without linux knowledge

 

my advice, keep reading about xpenology and its problems (dig into some of the problems people report and how often it happens) and consider a different system (like free nas for more safer storage with ZFS or open media vault when its less about special features in dsm)

 

more back to you question, it depends on how you plan, there are boars with 12-20 ports but they can get spendy, if full atx or flex atx is possible you have more options, keep in ming that most of the boards have no 10G nic, so you will have to plan on (at least) pcie 4x slot for the 10G nic and one at least 8x slot for a storge controller, like 4 or 8 port, if its just 4 port then plan 2 slots so on most systems you will have 4-6 sata onboard + 8 sata you add to get 12-14 your ports

plan 4 port cards if you stick to ahci (safer way when it comes to xpenology and the efforts of synology to prevent using dsm on other hardware)

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Synology doesn't provide a DAS connectivity option to date.  I had a similar desire to use DSM as the back end storage to a device that only was able to connect via USB.  I was able to make this work by purchasing a $25 "NanoPi NEO2" which is a tiny Linux computer that 1) had a gigabit Ethernet interface, and 2) supported USB OTG mode.  Then I built a sparsely populated image file on a Synology share and NFS mounted on the NanoPi, and used the Linux g_mass_storage gadget to emulate a USB drive from the image file.

 

A Raspberry Pi only has a 100MB Ethernet and that's not fast enough to provide performance similar to traditional USB DAS.

 

Edited by flyride
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On 9/18/2018 at 7:26 AM, flyride said:

I had a similar desire to use DSM as the back end storage to a device that only was able to connect via USB.  I was able to make this work by purchasing a $25 "NanoPi NEO2" which is a tiny Linux computer that 1) had a gigabit Ethernet interface, and 2) supported USB OTG mode.  Then I built a sparsely populated image file on a Synology share and NFS mounted on the NanoPi, and used the Linux g_mass_storage gadget to emulate a USB drive from the image file.

 

Very interesting. NanoPi Neo behaves something like virtual USB (network) mass storage. right ?

I think it's awesome idea.

 

What device you connect this to ? 

 

Personally, I don't have any good usage for this now,

but someone using DVR function of TV or gamer using PS4, XBox, etc. may be interested in this.

 

Could you share more detail on somewhere ?

 

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Ok, given that this emulates the DAS connectivity that OP was interested in, I guess it's not a thread hijack!

 

The fact is that I am using this to emulate USB storage for a HDTV DVR, so good guess on your part.

 

Linux "gadget" module g_mass_storage is used to enable storage emulation functions using USB OTG mode on a compatible device.  Gadgets can do other things, including LAN over USB, serial I/O over USB, etc.  Which behavior is dependent upon the module loaded.  Reference information here and here

 

Part A: Configure the pi-type single-board computer (SBC - in my case, the Neo2)

I'm using armbian as the OS on my Neo2.  Raspbian and other distros will have similar methods, but the configuration files and locations may vary.

 

1. Enable the device tree overlay by appending the following to /boot/config.txt

dtoverlay=dwc2

2. Load the gadget modules on boot by adding the following lines to /etc/modules-load.d/modules.conf

dwc2
g_mass_storage

The SBC will need to be rebooted to activate the modules.

 

Part B: Set up a shared folder and image as storage on DSM

 

1. If not enabled, go into Control Panel and enable NFS.  Under Advanced Settings, set 32K read and write packet sizes.

 

2. Configure a shared folder on DSM and enable NFS services on it, to include the host/IP of the SBC.  Use these parameters:

  • Privilege: read/write
  • Squash: no mapping
  • Security: sys
  • Enable synchronous: yes

3. Configure a target image file in the root of the shared folder.

  • This can be done from the SBC after mounting the shared folder via NFS, or from the DSM command line
  • A sparse file will only allocate storage in DSM when it is actually used by the SBC
  • Refer to the reference links above for configuration details and examples

Part CConfigure the NFS and module scripting on the SBC

 

1. Configure the NFS mount target on the SBC

mkdir -p /mnt/nfs_client/<shared folder name>

2. Sample SBC mount/startup script, assuming a prepared image file called image.img on shared folder share, on volume1, on DSM with IP address 10.2.3.4

sudo mount -t nfs -o nolock,wsize=32768,rsize=32768,intr,hard 10.2.3.4:/volume1/share /mnt/nfs_client/share
sudo modprobe g_mass_storage file=/mnt/nfs_client/share/image.img stall=0 iSerialNumber="1234567890" nofua=1

3. Sample SBC stop/dismount script to complement the above.  Troubleshooting information should be visible in /var/log/messages

sudo modprobe -r g_mass_storage
sudo umount /mnt/nfs_client/share

4. Set up the NFS mount and module load on SBC bootup by adding the startup script to /etc/rc.local

 

I prefer this over /etc/fstab NFS mount because it eliminates any mismatched service issues between NFS and the g_mass_storage module initialization.

Edited by flyride
formatting
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Wow, thank you for sharing all of this. 

I don't have enough time to try this, but I want to someday soon.

It's quite interesting and useful.

 

I think it's better to post this contents to another thread to notice at least DVR users. :) 

 

Currently, I feel I have to check every contents in this forum, because of the improper or inaccurate thread title. :(

 

Edited by benok

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Guys, I have to take time to give you a good answer, I will do soon.

But for now, thank you very very much!

 

Alex

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