In addition to what Dario mentioned, background merges happen all the time, optimize is just a special case (and very expensive).
You say “one of my Solr cores has 47G”, but segment merging can easily occur on multiple cores at once, so that’s not definitive. We usually recommend that people have at least as much free space on disk as the aggregate of _all_ the cores/replicas on a physical machine. More than you may want to know about segment merging: https://lucidworks.com/post/segment-merging-deleted-documents-optimize-may-bad/ Best, Erick > On Apr 23, 2020, at 4:38 AM, Dario Rigolin <dario.rigo...@comperio.it> wrote: > > When solr starts an optimization of the index you have to have free at > least same size (I don't know if 3 times is correct) of the core you are > optimizing. > Maybe your free space isn't enough to handle the optimization process. > Sometimes you have to restart the Solr process to have released more space > on the filesystem, couple of time solr didn't release all space. > > > > Il giorno gio 23 apr 2020 alle ore 10:23 Kayak28 <kaya.ota....@gmail.com> > ha scritto: > >> Hello, Community: >> >> I am currently using Solr 5.3.1. on CentOS. >> The other day, I faced an error message that shows >> " java.io.IOException: No space left on device" >> >> My disk for Solr has empty space about 35GB >> and the total amount of the disk is 581GB. >> >> I doubted there was no enough space for Linux inode, >> but inode still has spaces. (IUse was 1% ) >> >> One of my Solr cores has 47GB of indexes. >> >> Is there a possibility that the error happens when I do forceMerge on the >> big core >> (which I believe optimize needs temporarily 3 times spaces of index-size)? >> Or is there any other possibility to cause the error? >> >> >> Any Clues are very helpful. >> >> -- >> >> Sincerely, >> Kaya >> github: https://github.com/28kayak >> > > > -- > > Dario Rigolin > Comperio srl - CTO > Mobile: +39 347 7232652 - Office: +39 0425 471482 > Skype: dario.rigolin
