I have inherited an ancient (1.4, I think) version of single node elasticstack running (well, not running at the moment).
My original plan was to logon and clear out indexes because the customer got a low disk warning. When I logged on Elastic wasn't running. I tried starting it so I could remove old indexes to clean up space. Now I cannot get elastic to actually start.
I am unable to get any information on why elastic search won't stay running. When I start elasticsearch java kicks off and the process starts. After about 30 seconds it dies and leaves a pid file behind (not sure if that is relevant) and the log file (/var/log/elasticsearch/elasticstack.log) is literally empty. I checked permissions all around nothing has changed and permissions appear as one would expect. The partition that houses the elasticsearch data is full, so I'm sure it was a couple weeks since the low disk space warning.
I was wondering if anyone had any ideas on how to get this thing running again (unfortunately I am unable to rebuild, migrate or upgrade because of the customer's "requirements"). I thought maybe to delete some indexes but I am not sure if that would break elasticsearch. Any help would be greatly appreciated.