Hi @gpriyanka ,
What specific version of Pulse 6 did you upgrade it to?
On 6.1, that is more of a warning only. It does that if there is 30% remaining on the disk. The maintenance job of Pulse should still kick-in and will try to help out in the maintenance of the diskspace from within its directory. If the diskspace remaining dips even further, Elasticsearch will be on read-only mode once it hits 15%.
Thanks for bringing this up! We will have a look on this area to check further and target to address it in an upcoming release.
Cheers!
Paul