orthanc and NAS storage

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Aaron Boxer

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Apr 18, 2014, 5:56:01 PM4/18/14
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Can orthanc support a NAS network storage, instead of using the local hard drive?  
Also, is it possible to load balance a cluster of orthanc servers (for redundancy)

Thanks!
Aaron

Sébastien Jodogne

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Apr 19, 2014, 4:30:47 AM4/19/14
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Can orthanc support a NAS network storage, instead of using the local hard drive?  

In the configuration file of Orthanc, you can specify the directory where to store the SQLite index ("IndexDirectory" option) and the DICOM files ("StorageDirectory" option):
 
These two options can point to separate directories. You can make "StorageDirectory" point to your NAS drive, keeping the SQLite index in your local hard drive. I would not recommend to store the SQLite index in the NAS drive, as it is unclear whether this could result in a corruption of the SQLite database. Furthermore, the SQLite file should not grow over 1GB for the average use.

Note that the same strategy can be applied with SSD drives instead of a NAS, to obtain a high-speed mini-PACS system.

Also, is it possible to load balance a cluster of orthanc servers (for redundancy)

This is not a built-in feature of Orthanc, but you can implement it through scripting with the REST API.

Concretely, you could have a single front-end instance of Orthanc that receives the incoming DICOM files. Then, using the "Changes API" and an external script (e.g. written in Python), you can monitor the incoming of the files, then forward these files to a set of back-end Orthanc servers. Similarly, an external script can query all the back-end servers to aggregate the content of these servers.
 
HTH,
Sébastien-

charro...@gmail.com

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Jun 24, 2016, 9:21:25 AM6/24/16
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Hi,

reviving a 2 years old thread.
We are in a research centre with several modalities (4 MR scanners). We are new to PACS servers, and naively our idea would have been to have one orthanc server per modality which would save the image data to separate shares, and one front end orthanc server in index only mode to present/search the files from all modalities.
Is it overkill and should get all the modalities pushing to a single orthanc server having a single storage pool?

We would greatly benefit from your insights.

Thank you in advance,

Cyril

Sébastien Jodogne

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Jun 25, 2016, 9:25:55 AM6/25/16
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Hello,

There is no definite answer to this question. It really depends upon your needs.

You must know that each modality will record its identity inside the "Station Name" tag (0008,1010). So, if you use a single Orthanc server, you can isolate the DICOM images from each modality by filtering this DICOM tag. Any DICOM viewer should allow you to apply such a filter.

You should not be afraid of storing all the images inside a single Orthanc, as using the PostgreSQL plugin would allow to store large amount of data, while providing enteprise-ready features for backup.

That being said, using 4 different instances of Orthanc also makes sense if you need isolation between the different modalities.

It is technically feasible to create one front-end Web server that would present the unified content of each Orthanc server, but this will require development on your side, by creating an external application (in PHP, Java, .NET, Python...) talking with the Orthanc servers through the REST API [1]. This is one of our long-term projects, but we unfortunately have no funding to launch it now.

HTH,
Sébastien-

Cyril Charron

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Jun 27, 2016, 11:47:41 AM6/27/16
to Sébastien Jodogne, Orthanc Users
Hi Sébastien,

thank you for the reply. It does make sense. I am quite convinced we are going to go the single repository route using the PostgreSQL plugin.

Thank you for the valuable insight,

Kind regards,

Cyril

__

Cyril Charron, PhD
Research Associate
CUBRIC Users' Website

CUBRIC
School of Psychology
Cardiff University
Maindy Road
Cardiff CF24 4HQ
Tel:  +44 (0)29 2068 8784

Harkant Singh

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Sep 30, 2017, 5:08:22 PM9/30/17
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I don't think it is so simple. I have been trying to use an external hdd to store Orthanc data, but Orthanc gives error "[boost::filesystem::status: Permission denied: "/media/pi/OrthancPiStorage/OrthancStorage"]" where OrthancPiStorage is my external HDD's label and Orthanc Storage is a folder on it where I want the data to go.

bertrand boutillier

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Oct 1, 2017, 6:47:56 AM10/1/17
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Hi,

I think you have a problem with linux, not with Orthanc.
On your USB disk, is your filesystem writable ? NTFS, for example, is
not by default under Debian (need ntfs-3g).
I used Orthanc with directories shared via NFS and hosted by NAS
Synology: no problem, just the question of the possible automatic reboot
of the NAS for update when Orthanc is still running (messages on this list).

B.
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Harkant Singh

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Oct 1, 2017, 10:24:46 AM10/1/17
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I am repeating what I wrote in the other post here as well - If it is not right to do so I am sorry.

I formatted my external drive to ext4 format and labelled it "OrthancPiStorage".

I let the linux distribution (Raspbian) mount it as it deems right.  It is mounted under "/media/pi/OrthancPiStorage" with "pi:pi" as owner and "drwxrwxr-x" as permissions.

I created a folder "OrthancStorage" in it. Its owner is again "pi:pi" with "drwxrwxr-x" as the permissions.

The "StorageFolder in "orthanc.json" is set to "/media/pi/OrthancPiStorage/OrthancStorage" - I get the error "Uncaught exception, stopping now: [boost::filesystem::status: Permission denied: "/media/pi/OrthancPiStorage/OrthancStorage"]" in the "/var/log/orthanc/Orthanc.log" (same log as in the first post).

Now I create a folder "OrthancStorage" in /home/pi folder. The folder "/home/pi/OrthancStorage" has ownership of "pi:pi" and permissions as "drwxrwxr-x".
The "StorageFolder" in "orthanc.json" is set to "/home/pi/OrthancStorage" - no error, the server runs perfectly.


I think you are right, this appears to be a problem with linux

Harkant Singh

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Oct 1, 2017, 10:30:56 AM10/1/17
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I am repeating what I wrote in the other post here as well - If it is not right to do so I am sorry.

I formatted my external drive to ext4 format and labelled it "OrthancPiStorage".

I let the linux distribution (Raspbian) mount it as it deems right.  It is mounted under "/media/pi/OrthancPiStorage" with "pi:pi" as owner and "drwxrwxr-x" as permissions.

I created a folder "OrthancStorage" in it. Its owner is again "pi:pi" with "drwxrwxr-x" as the permissions.

The "StorageFolder in "orthanc.json" is set to "/media/pi/OrthancPiStorage/OrthancStorage" - I get the error "Uncaught exception, stopping now: [boost::filesystem::status: Permission denied: "/media/pi/OrthancPiStorage/OrthancStorage"]" in the "/var/log/orthanc/Orthanc.log" (same log as in the first post).

Now I create a folder "OrthancStorage" in /home/pi folder. The folder "/home/pi/OrthancStorage" has ownership of "pi:pi" and permissions as "drwxrwxr-x".
The "StorageFolder" in "orthanc.json" is set to "/home/pi/OrthancStorage" - no error, the server runs perfectly.

I think you are right this appears to be a problem with linux.



On Sunday, October 1, 2017 at 4:17:56 PM UTC+5:30, Bertrand Boutillier wrote:

Sébastien Jodogne

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Oct 5, 2017, 2:54:08 PM10/5/17
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Hello,

If you are using the official "orthanc" package from the Raspbian distribution, the Orthanc server automatically starts at boot as user "orthanc" (in the "orthanc" group).

My feeling is that you are trying to manually start Orthanc as default user "pi", whereas the Orthanc server already runs as a background daemon with user "orthanc". Run the following command to check whether the Orthanc service is running:

# sudo /etc/init.d/orthanc status

The configuration file is at "/etc/orthanc/orthanc.json". To restart the Orthanc server, type:

# sudo /etc/init.d/orthanc restart

HTH,
Sébastien-

Harkant Singh

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Oct 7, 2017, 4:17:11 AM10/7/17
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Thanks.

I was actually trying to use external HDD to use to store data while using Orthanc from Raspberry Pi. It was working initially when I was using Raspbian Jessie, after upgrading to Raspbian Stretch it started giving errors. It worked after I used the HDD to load operating system from (as described by #mxcum167 in https://www.raspberrypi.org/forums/viewtopic.php?t=9117 ).

Mychael Mario

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Feb 5, 2020, 12:50:08 AM2/5/20
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Dear Sébastien,

I try to move my storage to other storage like NAS and make mapping drive in my Windows. When i run Orthanc always problem but when i used my local drive i can run orthanc well. Can you help me what problem ?
Note : I change "configuration.json"  with "StorageDirectory" : "Z:\\Testing"

Thank you
Mike

Sébastien Jodogne

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Feb 5, 2020, 5:00:26 AM2/5/20
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Hello,

Maybe this previous post could help?

I am not a Microsoft Windows user, so I can't provide guidance by myself.

Regards,
Sébastien-
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