Mongodb 2.4 32 not create collection after filesize 2gb but datasize1mb

MongoDB 2.4 32 not create collection after filesize 2gb but data size 1 MB

I finally found the root cause of this problem where fileSize is ~=2GB and dataSize is few MBs and its solution.

Root cause - If the database uses a capped collection, MongoDB 2.4 MMAP storage engine allocates a fixed amount of disk space for this capped collection. Any attempt to create new collections after the datafile size is reached will cause MongoDB 2.4 to throws error.

cant map file memory-mongo requires 64 bit build for larger datasets

In my case, I was creating capped collections dynamically.

Solution - Any operations using the mongodcommand to repair database will fail as it requires additional memory to perform these operations.
So use mongodump to get the database dump along with --repair which will create a dump without "capped" limit for all capped collections and then mongorestore it

Step 1 - Take the dump of the database along with --repair

mongodump --username <username> --password <password> --dbpath <path> --db <db> --out <path> --repair

Step 2 - Drop database

db.dropDatabase()

Step 3 - Restore the dump

mongorestore --username <username> --password <password> --dbpath <path> --db <db> <path>

Step 4 - Convert a Collection to Capped(Optional)

db.runCommand({"convertToCapped": "mycoll", size: 100000});

Hope this helps.

db.stats()

{ 
    "db" : "admin", 
    "collections" : NumberInt(40), 
    "objects" : NumberInt(998), 
    "avgObjSize" : 196.9498997995992, 
    "dataSize" : NumberInt(196556), #~1MB
    "storageSize" : 1478905856.0, 
    "numExtents" : NumberInt(42), 
    "indexes" : NumberInt(50), 
    "indexSize" : NumberInt(433328), 
    "fileSize" : 2197028864.0, #2GB
    "nsSizeMB" : NumberInt(16), 
    "dataFileVersion" : {
    "major" : NumberInt(4), 
    "minor" : NumberInt(5)
    }, 
    "ok" : 1.0
}