mongodb 存档格式是什么？

Question

我已经使用它们的存档选项备份了一些 mongoDB，但我不能简单地解压缩它们。当我通过一些步骤来解压缩数据时，存档看起来像是一个大文件中的整个数据库。我想获取各个集合的文件。有办法吗？

$ tar -xvf valk.archive
tar: Unrecognized archive format
tar: Error exit delayed from previous errors.
$ file valk.archive
valk.archive: gzip compressed data, original size 13953183
$ gunzip valk.archive
gunzip: valk.archive: unknown suffix -- ignored
$ unzip valk.archive
Archive:  valk.archive
  End-of-central-directory signature not found.  Either this file is not
  a zipfile, or it constitutes one disk of a multi-part archive.  In the
  latter case the central directory and zipfile comment will be found on
  the last disk(s) of this archive.
unzip:  cannot find zipfile directory in one of valk.archive or
        valk.archive.zip, and cannot find valk.archive.ZIP, period.
$ mv valk.zip valk.gz
$ gunzip valk.gz
$ open .
$ tar -xvf valk
tar: Unrecognized archive format
tar: Error exit delayed from previous errors.
$ head valk
TemplateDatametadata�{"options":{},"indexes":[{"v":2,"key":{"_id":1},"name":"_id_","ns":"valk.TemplateData"}],"uuid":"f52402b5aba24856b072d57cc3e46a72"}size-dbvalkcollectioMetricsmetadata�{"options":{"capped":true,"size":10485760,"max":1000000},"indexes":[{"v":2,"key":{"_id":1},"name":"_id_","ns":"valk.Metrics"},{"v":2,"key":{"openid":1},"name":"openid_1","ns":"valk.Metrics"}],"uuid":"43d92ff01815432c95dac5a2e05a64c0"}size�dbvalkcollection
AppConfigmetadata�{"options":{},"indexes":[{"v":2,"key":{"_id":1},"name":"_id_","ns":"valk.AppConfig"}],"uuid":"df633b0a43184de38e8b8ea7489cda3e"}size�dbvalkcollecMinibotZonesmetadata�{"options":{},"indexes":[{"v":2,"key":{"_id":1},"name":"_id_","ns":"valk.MinibotZones"}],"uuid":"095bbac0d17640be9e27dffe681b7d83"}size�dbvalkcollection    ChatLogsmetadataQ{"options":{"capped":true,"size":104857600,"max":10000000},"indexes":[{"v":2,"key":{"_id":1},"name":"_id_","ns":"valk.ChatLogs"},{"v":2,"key":{"openid":1,"createdAt":1},"name":"openid_1_createdAt_1","ns":"valk.ChatLogs"},{"v":2,"key":{"createdAt":1},"name":"createdAt_1","ns":"valk.ChatLogs"}],"uuid":"70586c82b3ae42cf8d9c47ad339ea55b"}size�dbvalkcollection

Answer 1

mongodump 存档格式是一种特殊用途的格式；您需要将 mongorestore --archive 与任何其他合适的选项一起使用。

例如，您可以使用 --nsInclude 选项（mongorestore 3.4+）按命名空间有选择地恢复多个集合。

有关 MongoDB 存档格式的更多信息（以及 tar 不适合的原因），请参阅： MongoDB 工具中的存档和压缩。其要点是：

General purpose archive formats, like tar, only support contiguous file packing within the archive. Using these archive formats for mongodump and mongorestore will create an unacceptable performance degradation as data from all collections will have to be written to and read from, in order. To support the concurrent behavior of these tools, we developed a special purpose archive format that supports non-contiguous files writes. The new archiving feature provides major gains in the efficiency of backup and restore operations.

mongodb 存档格式是什么？

what is mongodb archive format?

restore

archive

mongodb