Not the answer you need?
Register and ask your own question!

Mongorestore hangs restoring a MongoDB 2.6 dump to a PS for MongoDB 3.0.8 wiredTiger

i90rri90rr EntrantInactive User Role Beginner
Hi all,

We are trying to migrate our MongoDB databases but we're stuck with this issue that seems to occur randomly; some times it hits in an early stage of the restore process, some other times it hits well beyond half of the restore process.

I found someone else posting a similar issue on stackoverflow:

OS: CentOS 7 KVM-guest
My mongod.conf file is as follows:
# cat /etc/mongod.conf
# mongod.conf, Percona Server for MongoDB
# for documentation of all options, see:

# Where and how to store data.
  dbPath: /var/lib/mongo
    enabled: true
#  engine: mmapv1
#  engine: PerconaFT
#  engine: rocksdb
  engine: wiredTiger

# Storage engine various options
#  mmapv1:
      cacheSizeGB: 1

# where to write logging data.
  destination: file
  logAppend: true
  path: /var/log/mongo/mongod.log

  fork: true
  pidFilePath: /var/run/

# network interfaces
  port: 27017





## Enterprise-Only Options:



As you see the cache is reduced to 1Gb as previously Mongo was crashing back to OS, presumably after getting out of memory.

Finally: they say that sometimes a picture is worth a thousand words so


  • i90rri90rr Entrant Inactive User Role Beginner
    Hi all,

    I finally could get along with the restore by enlarging the wiredTiger cacheSizeGB to 2gb.
    I'm not sure though that it was strictly an out-of-memory issue because I had a tail -f on the Mongo log file and there was nothing there that could lead me think the cache was getting out of space, so I will keep a close eye on this issue and see how it behaves.

    In any case I hope this post can help all of those that may happen to stumble with the same issue.

Sign In or Register to comment.

MySQL, InnoDB, MariaDB and MongoDB are trademarks of their respective owners.
Copyright ©2005 - 2020 Percona LLC. All rights reserved.