I am using IXOS 3rd party utility to maintain invoices (images) in my client's SAP system. We have a DR (Disaster Recovery) setup & for that I need to synchronize my /ixos filesystem (with size more than 50 GB) between two servers say x182 & x050.
Initially I thought to tar the directory then rcp it & then un'tar it at destination but this method is giving me problems related to storage of the tar file & the time it will take it to rcp the huge tar file.
I tried RDIST, but that also takes lot of time (around 5-6 hours).
Can anybody suggest me any other solution to this problem?
10GB per hour sounds half decent. How fast is the connection? If the majority of the files are not changing after you have copied them once, rsync would sound like the ideal solution.
If its a 50GB SAP system I assume that most of that size is an Oracle database?
If thats the case then Oracle must not be active when you make a DR copy of it.
Oracle has lots of files open and keeps making changes. If you are making copies of it over a several hour window then your copy is likely to be junk (especially given SAP likes updating Oracle).
I think IXOS is an archiving solution isnt it? If the IXOS archive is on a unix filesystem and is not an open database then you can copy those files whenever you like. The files in an IXOS archive are almost never going to change so using a utitility like rsync is a possibility. Rsync will only copy the stuff that has changed since the last time it ran.
To answer your actual question. Both rdist and rsync will only copy the files that have changed. Rsync is considered to be better in most circles and comes with the ability to only copy the blocks that have changed in files rather than copy whole files (there are cavaets on using that functionality though). Rsync has more functionality in general.
If you ran rdist to an empty directory on your DR machine then it would have copied the entire filesystem. Try running it a second time when there is already a full copy in place on the remote machine, and it should only copy across and changes since the last time it ran. Use rsync, not rdist though
