Drivepool + iSCSI user experience ?

[AlexL]

Hi all, I have for years been slowly building adding drives to my Win10 NAS, seeking a silent HW option as well as simple to understand and recover once SHTF.  

My setup today is:

• Shuttle DS437T Celeron 1037U 1.8 GHz/16GB RAM/Intel SSD - Main unit (chosen for the many USB ports (8) mainly, and fanless design)

• Windows 10 - OS

• External 2.5" HDDs of various sizes - Storage

• Storage spaces - Software used like a drive extender (no parity)

 

My long range plan is to move away from SS to Drivepool to get a more simplified setup in case of SHTF. For this I am planning to use Gnubee's (https://www.crowdsupply.com/gnubee/personal-cloud-1/) for my many 2.5 drives that are damn near silent, and have it be a iSCSI target on OpenMedia vault via a dedicated 100mbit switch. The Shuttle will therefore be a iSCSI initiatior, with drivepool holding it all together.

So my question is:

* Has anyone attempted Drivepool on iSCSI targets ?

- If yes, what was your experience ? What where the pros and the cons? 

- What transfer speeds should I expect ?

Thanks!

A

[Christopher (Drashna)]

You mean making a pool out of iSCSI target drives?  That should work, and I do believe that I have tested that (but it was a while ago).  You shouldn't see any issues with doing so.

 

 

As for pros and cons....

 

Are you using 10gig networking?  If not, the max throughput combined for the system is going to be ~120MBs.  that will be divided between all of the iSCSI devices, and with anything accessing the system, and any access it makes. 

 

So, you may have a nasty bottleneck when it comes to the network here.   It can/will impact performance, especially when using duplication, when the pool is actively balancing, and other such.

 

Otherwise, it will work, and would allow you to easily migrate the pool to a new system.

 

 

 

As for expected speeds? 

 

Without duplication, 80-100MB/s tops

With duplication, half that, or worse. 

[AlexL]

Thank you for the quick answer!

 

I will be running a dedicated 1gb switch for the "SAN" portion, and GnuBee which I plan to have as iSCSI server has 2 NICs which I hope I could team to get 2Gbit. So I somehow hope I get double the transfer rate you just specified

[p3x-749]

...a single client connection will not benefit from a teamed link...only multiple concurrent clients will, i.e. a 2xGbit teamed link will give each client up to a full 1xGbit link at the same time

[Christopher (Drashna)]

...a single client connection will not benefit from a teamed link...only multiple concurrent clients will, i.e. a 2xGbit teamed link will give each client up to a full 1xGbit link at the same time

 

 

This.  And even still, the client is still limited in performance.  That 120+MB/s is the max speed for a single gigabit connection. 

[AlexL]

Thanks for pointing that out!

 

So no way to get a drivepool with network nodes on a silent machine then? >(

 

I really wanted Drivepool for its simplicity of recovering, adding drives and also NTFS filesystem. 

[p3x-749]

....not with the speed performance of a teamed link, in a way you've had in mind.

However, with a spinning disk, a sustained performance of 120MBytes/sec and above is only achievable with striped reading (for drivepool, AFAIK striped writing does not exist).

So, the typical limit here is the drive speed, not the link speed, isn't it.