Hi

we have a sharepoint farm for uploading documents in huge number daily and we conifgured RBS for sql server content db.

we are facing issue in sql server instance:

Suddenly the SQL server instance restarts and sometimes failover to node1 and sometimes just restart and keep running on the current server

and did some invistagations we found that 

-Analysis of data shows that the slowness of IO for tempdb.ldf is cause of the issue

-tried to check tempdb using db properties but I couldnt see the properties it gives me error,

-There might be a big transaction locking the tempdb.

-

Also noted  that there are lot of errors:
 The transaction log for database 'MOJSP_SearchApp_CrawlStoreDB_32fdb1522c5249088db8b09c1917dbec' is full due to 'ACTIVE_TRANSACTION'

This might also be part of the problem causing locking.

we found the errors like

The transaction log for database 'EMP_SP_SearchApp_CrawlStoreDB_32fdb1522c5249088db8b09c1917dbec' is full due to 'ACTIVE_TRANSACTION'

I see that log_reuse_wait_desc (reuse of transaction log space is currently waiting on as of the last checkpoint) is 'ACTIVE_TRANSACTION'