Hi,
I would go with export/import similar as I have just reply to your other older post/question.
However this covers Archive indices only, e.g. a case where you need to just migrate CMOD and (e.g. TSM) storage stays the same.
If you also need to export underlying data, I have used export using dsmc (as it is a bit faster) as:
dsmc retrieve -server=TSMServerName -virtualnode=TSMNode -password=NODEPasswd -replace=no -ifnewer -filesonly -filelist=InputFileList MyLocalDir/
The "InputFileList " has all of the doc names but no more then ~5000 per one execution (this is just my experience) one name per line.
Important: Don't forget each of doc_name as 1234FAAA does have hidden 1234FAA1 file not visible in CMOD but present on the storage.
However, arsadmin retrieve works also just fine. One comment, though: In a case there is an error while retrieving data from storage e.g. corruption, not found or so, then arsadmin would stop with partially retrieved file and would not progress with rest in acase you have specified multiple files on one command line!!
Doing arsadmin retrieve one by one would be very slow as it does: instantiate process, authenticate, write system log record and clean up after, for each of your 100M files !!! That's a lot of fluff for nothing. However, if you still want to go this route I would suggest at least to disable logging for respective AG(s).
Once exported you can loaded to target system with arsadmin store. Also, if you have configured a new Node names on your target and you have copied your segment tables, don't forget to update NIDs (mostly pri_nid) as well arsres.pri_nid
Hope this helps,
N.