Long-Term Archive Directory Replication

pacsi · Post by **pacsi** » Mon Jul 25, 2011 9:19 am

Hello,

we use PacsOne for many years now, but have just started to use a Thecus NAS (8800Pro) as LTA via SMB, which works perfectly.

Now we want to add some extra fault tolerance by automatically replicating the content of the NAS to another Thecus 8800Pro in a different data center.

Thecus provides a builtin mechanism called nsync (similar to rsync) to enable replication of two NASes. Sadly, it doesn't work, because it cannot handle the great number of files (PET/SPECT data, millions of small files).

Any idea on how to handle this? Is there a way to enable tar-archiving in PacsOne before the files are moved to the LTA to reduce the number of files?

Thanks in Advance!

Regards,
Pacsi

Post by **pacsone** » Tue Jul 26, 2011 2:32 am

If you want to add redundancy at the file storage level, then you should use RAID instead of the file synchronization service such as n-sync, because the replication occurs at disk-level for RAID which is much faster and reliable than the file synchronization which occurs at file system level.

Besides, using file synchronization to replicate a file system is merely a backup but not real redundancy, since the non-realtime nature of the file synchronization is not suitable for fully redundant systems.

pacsi · Post by **pacsi** » Fri Sep 02, 2011 6:58 am

Thanks for the quick response. You are right, it is more like a backup. Each of the NAS uses RAID6 for redundancy.

Initial copying of the whole dataset (2TB, 9mio files) from one NAS to the other takes about 10 days using a robocopy based backup tool.

It would be great if PacsOne can provide the possibility to enter two or more LTA-Locations and would copy the files directly to all locations. This would have the advantage, that if one system is not available, the data could still be viewed.

For the moment we have to manually copy the additional files after the weekly automatic aging run.

Thanks for your help!