Problem description

The below-mentioned database error occurs while performing a direct download on a Mac OS.

Unable to open database file.

Cause

The direct download utility creates Python sub-processes. if the number of sub-processes exceed the open file limit set by the operating system, the direct download utility fails.

Traceback

2018-08-20 16:31:47,667 [ERROR] - Error: unable to open database file in metadata download for user:  user@xyz.com, device: User’s MacBook Pro, and webdav url:  https://restore-c71-cloud.druva.com/.../1/1/Messages/

Traceback (most recent call last):
  File "/Users/insync/webdav/webdevdirectdownload/webdevdirectdownload/WebdavDirectDownload/5.9.5_CU2_patch1/build/inSyncDirectDownload/out00-PYZ.pyz/inSyncDirectMetadataDownload", line 307, in process_queue
  File "/Users/insync/webdav/webdevdirectdownload/webdevdirectdownload/WebdavDirectDownload/5.9.5_CU2_patch1/build/inSyncDirectDownload/out00-PYZ.pyz/inSyncDirectMetadataDownload", line 464, in getDeviceMetadata
  File "/Users/insync/webdav/webdevdirectdownload/webdevdirectdownload/WebdavDirectDownload/5.9.5_CU2_patch1/build/inSyncDirectDownload/out00-PYZ.pyz/inSyncDirectMetadataDownload", line 402, in parse_propfind_response
  File "/Users/insync/webdav/webdevdirectdownload/webdevdirectdownload/WebdavDirectDownload/5.9.5_CU2_patch1/build/inSyncDirectDownload/out00-PYZ.pyz/inSyncDirectMetadataDownload", line 206, in mark_download_done
  File "/Users/insync/webdav/webdevdirectdownload/webdevdirectdownload/WebdavDirectDownload/5.9.5_CU2_patch1/build/inSyncDirectDownload/out00-PYZ.pyz/inSyncDirectDownloadDevices", line 300, in add_to_download_done_list
  File "/Users/insync/webdav/webdevdirectdownload/webdevdirectdownload/WebdavDirectDownload/5.9.5_CU2_patch1/build/inSyncDirectDownload/out00-PYZ.pyz/inSyncDirectDownloadState", line 343, in is_relative_path_present
OperationalError: unable to open database file

Resolution

To resolve this issue, find the open file limit of the OS and change the limit to a higher number. The steps to verify and increase the open file limit are as follows:

Open the Terminal on your Mac device and run the below command.
```
"ulimit -a"
```
The limit is displayed against open files.
Increase the limit to a higher value with the command:
```
"ulimit -n <higher limit value>"
```
For example:
```
"ulimit -n 10000"
```

The direct download utility functions without this error subsequent to this change.