Restoring WiredTiger collection without WiredTiger.wt/turtle file

[Wakahisa]

I came across an issue where MongoDB crashed, and now I'm trying to recover my files. I restarted mongod but I only see an empty local collection.

I've tried to manually recover the *.wt collections, but it seems they depend on metadata on catalog files. Is there a way to recover these without catalog data? I'm using MongoDB 3.2.9 on Ubuntu.

Thanks

[Amar]

Hi,

To better understand the situation, could you provide more information on:

• How did the instance crash and if there were any messages when the crash happened?
• What steps were taken to manually recover the files?
• How was the instance started afterwards and where there any messages in the logs?
• The parameters/config file used to start mongod before and after the crash.

In general it is very important to have backups of MongoDB as they are usually the best way out of such situations.

Regards,

Amar

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[liang...@gmail.com]

I deleted WiredTiger.wt, _mdb_catalog.wt, storage.bson files and cannot be found, only collection-******.wt and index-******.wt left. then I restart MongoDB, I only see an empty local collection. Is there a way to recover these without catalog data? I'm using MongoDB 3.2.9 on Windows.

在 2016年8月26日星期五 UTC+8上午9:51:45，Amar写道：

[Kevin Adistambha]

Hi

I deleted WiredTiger.wt, _mdb_catalog.wt, storage.bson files and cannot be found, only collection-**.wt and index-**.wt left. then I restart MongoDB, I only see an empty local collection. Is there a way to recover these without catalog data?

Unfortunately those files are important WiredTiger metadata files that cannot be rebuilt from other files. The best way to proceed if those files are deleted is to restore from a known good backup.

May I ask the reason why you deleted those files, and the events that lead to the deletion of those files? Please note that manually changing the content of MongoDB’s dbpath directory is strongly not recommended since it can lead to unrecoverable data loss.

Best regards,
Kevin

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