## 5.4 Production Checklist 

The following checklists provide recommendations that will help you avoid issues in your production MongoDB deployment. 

## 5.4.1 Operations Checklist 

The following checklist, along with the Development (page 314) list, provides recommendations to help you avoid issues in your production MongoDB deployment. 

## Filesystem 

• Align your disk partitions with your RAID configuration. 

• Avoid using NFS drives for your dbPath . Using NFS drives can result in degraded and unstable performance. See: Remote Filesystems (page 201) for more information. 

– VMWare users should use VMWare virtual drives over NFS. 

• Linux/Unix: format your drives into XFS or EXT4. If possible, use XFS as it generally performs better with MongoDB. 

– With the WiredTiger storage engine, use of XFS is strongly recommended to avoid performance issues found when using EXT4 with WiredTiger. 

– If using RAID, you may need to configure XFS with your RAID geometry. 

• Windows: use the NTFS file system. Do not use any FAT file system (i.e. FAT 16/32/exFAT). 

## Replication 

• Verify that all non-hidden replica set members are identically provisioned in terms of their RAM, CPU, disk, network setup, etc. 

• Configure the oplog size (page 628) to suit your use case: 

– The replication oplog window should cover normal maintenance and downtime windows to avoid the need for a full resync. 

– The replication oplog window should cover the time needed to restore a replica set member, either by an initial sync or by restoring from the last backup. 

• Ensure that your replica set includes at least three data-bearing nodes with w:majority write concern (page 130). Three data-bearing nodes are required for replica set-wide data durability. 

• Use hostnames when configuring replica set members, rather than IP addresses. 

• Ensure full bidirectional network connectivity between all mongod instances. 

• Ensure that each host can resolve itself. 

• Ensure that your replica set contains an odd number of voting members. 

• Ensure that mongod instances have 0 or 1 votes. 

• For high availability, deploy your replica set into a minimum of three data centers. 

