Are you physically swapping the disks to introduce the new index? Or having both disks mounted at the same time?
If the disks are simultaneously available, can you just swap the cores and then delete the core on the old disk? https://cwiki.apache.org/confluence/display/solr/CoreAdmin+API#CoreAdminAPI-SWAP We periodically move cores to different drives using solr's replication functionality and core swapping (after stopping replication). However, I've never encountered solr deleting an index like that. On Wed, Jun 14, 2017 at 2:48 PM David Hastings <hastings.recurs...@gmail.com> wrote: > I dont have an answer to why the folder got cleared, however i am wondering > why you arent using basic replication to do this exact same thing, since > solr will natively take care of all this for you with no interruption to > the user and no stop/start routines etc. > > On Wed, Jun 14, 2017 at 2:26 PM, Mike Lissner < > mliss...@michaeljaylissner.com> wrote: > > > We are replacing a drive mounted at /old with one mounted at /new. Our > > index currently lives on /old, and our plan was to: > > > > 1. Create a new index on /new > > 2. Reindex from our database so that the new index on /new is properly > > populated. > > 3. Stop solr. > > 4. Symlink /old to /new (Solr now looks for the index at /old/solr, which > > redirects to /new/solr) > > 5. Start solr > > 6. (Later) Stop solr, swap the drives (old for new), and start solr. > (Solr > > now looks for the index at /old/solr again, and finds it there.) > > 7. Delete the index pointing to /new created in step 1. > > > > The idea was that this would create a new index for solr, would populate > it > > with the right content, and would avoid having to touch our existing solr > > configurations aside from creating one new index, which we could soon > > delete. > > > > I just did steps 1-5, but I got null pointer exceptions when starting > solr, > > and it appears that the index on /new has been almost completely deleted > by > > Solr (this is a bummer, since it takes days to populate). > > > > Is this expected? Am I terribly crazy to try to swap indexes on disk? As > > far as I know, the only difference between the indexes is their name. > > > > We're using Solr version 4.10.4. > > > > Thank you, > > > > Mike > > >
