- Troubleshooting >
- Backup
Backup¶
Logs Display MongodVersionException¶
The MongodVersionException can occur if the
Backup Daemon’s host cannot access the
internet to download the version or versions of MongoDB required
for the backed-up databases. Each database requires a version of
MongoDB that matches the database’s version. Specifically, for each
instance you must run the latest stable release of that release
series.
If the Daemon runs without access to the internet, see Configure Deployment to Have Limited Internet Access to install the appropriate binaries.
Insufficient Oplog Size Error¶
If you have set the mms.backup.minimumOplogWindowHours, Ops Manager checks to see if the cluster’s oplogs can store a given number of hours of data. It bases on recent oplog usage patterns from the last 24 hours.
If the oplogs lack capacity, the oplogs may have turned over multiple times. This creates a gap between where a backup ends and an oplog starts.
If this oplog size check fails:
You cannot enable backups
Ops Manager displays the following:
Warning
Insufficient oplog size: The oplog window must be at least <duration> hours over the last 24 hours for all members of replica set <deploymentName>. Please increase the oplog.
If possible, wait to start a backup until the oplog has had sufficient time to meet the size requirement.
Warning
Do not change the minimum oplog size unless you are certain smaller backups still provide useful backups.
MongoDB recommends only changing this value temporarily to permit a test backup job to execute. The minimum oplog size value should be reset to the default as soon as possible.
Understanding the risks given, you can start backups using this changed minimum value. Once you pass the 24 hour mark, you should reset this minimum value to preserve the sanity check for the global Ops Manager installation going forward.