Hello,
There is another thread with the same title and it looks like the same problem however there is no .lock after the file directory path. Is it the same problem?
IOError: [Errno 30] Read-only file system: '/opt/splunk/var/run/splunk/session-0ccaa896b29d978655b877a32ab8fdf59496d515'
After digging around our issue was VMware related. I would give you the link but I don't have enough karma.
"Linux based file systems become read-only (51306)" (VMWare knowledge base)
You don't specify, but I deduce, from the file path in the error message that you are running a Linux install. A file-system switching to "read only" is usually a sign of a bigger problem - file-system corruption detected by the kernel, causing it to switch to read-only to stop any further corruption. I don't think you have a Splunk problem, I think you have a sysadmin problem: a file-system needing taking offline and fixing, and a possible hardware issue (usually memory, or impending disk failure).
Yes, it's a linux install. Thank you.