Recover DICOM files from partial OrthanC directory backup

General
1

Dear Sebastien / Alain,

We have a client that had about 20 TB of Dicom files stored on a RAID5 array.

One disk failed (#16), but after replacing failed drive, during reconstruction, a 2nd HDD #8) failed too (causing RAID to go from degraded to failed).We have had sisk failure in the past, but never 2 disks of same array at same time…

After restart, the disk #8 came back online, and we started to replicate (rsync) the file to another server. Unfortunately, not only the copy speed was very slow (due to degraded array), but after a couple of hours the drive #8 failed again,

We achieved to copy 4TB of data, after several restarts, but now disk #8 looks dead.

I do not understand exactly how data is “spread” over the directories, but:

  1. Is there a way to have (new install of) OrthanC “discover” the stored dicoms (and add them to the new OrthanC instance)? Using ImportDicomFiles.py?

  2. If a study si “spread” over various directories, and part of the data is missing, will it import the “available” images, not import nothing, or cause failure in the import process?

We have backup (in offline disks) to reconstruct most of the 20 TB data, so we hope to be able to recover most data. But we will definitely migrate to RAID6, and we are now monitoring SMART HDD data to detect pre failure signs.

Many thanks in advance for you help.

Cedric.

2

Hi.

  1. Forget about RAID5 - use RAID6: 2 disks broke to failure and much lower probability to broke whole array at reconstruction
  2. For import images to new Orthanc instance use ImportDicomFiles.py or OrthancImport.py
  3. at end you will get whole/partial studies.

RAID5 is suxx. For BIG instances use RAID6 (or NAS + NFS or SAN + iSCSI/NFS)

3

@cherednichok.y Thank you very much for the feedback.

4

Hello,

Yes, ImportDicomFiles.py is the way to go if you want to replicate the content of an Orthanc server. Check out the Orthanc Book.

Note that there also exists the script OrthancImport.py which provides more options.

Depending on your needs, you might also want to consider the so-called “advanced storage” plugin in indexer mode, if you don’t want to duplicate all the files.

Yes, the scripts will import all the available images in the considered directories.

Kind Regards,
Sébastien-