Confused by CDDB file options

[keithG]

Can someone confirm the difference between the cddb download options for B2 offline use. Just want to update the internal cddb supplied with the B2 unit in Mid 2016 to the March 2020 version of the freedb.

 Investigation on the ‘Web site – Questions - Menu Overview – USB Menu - load database’ provides a link that infers access to download the latest freedb version. This is a 1.5G file.

 The B2 Home Web web page (left side) under ‘New Album Database – b2 download this file’ provides a path to a combined freedb + musicbrainz download which is also 1.5G.

 I’m puzzled as both point to a 1.5G file on google drive. I expected the freedb to be smaller than the combined freedb + musicbrainz file, not the same size, hence the main question.

 The B2 ‘Menu – Settings - Maintenance - Get Mydb’ indicates that it downloads the latest freedb cddb version. Is this still correct?  As this is a long download, how does the B2 behave if the internet connection drops out?  Hence is the provision of a file download a safer route?

 Am I right in assuming that these all overwrite the factory supplied cddb on the SD card.

 Thanks

Keith G

[Peter Lowham]

Hi Keith,

I downloaded both CDDB files and ran a binary 'compare' between them.  These two files are identical.  I have attached a 'JPG' screenshot showing the output of the comparison.  So it is just a difference in terminology on the website.

The B2 ‘Menu – Settings - Maintenance - Get Mydb’ does download the latest (combined) CDDB.  The way that this process works is as follows.

1.  When you start 'Get mydb', the B2 begins to download a file called 'mydb.gz'.  This is a compressed version of 'mydb' and is downloaded into the same directory as the currently active 'mydb' file.

2.  When the download of 'mydb.gz' completes, the currently active 'mydb' file is deleted from the directory.

3.  The 'mydb.gz' is then decompressed in a newly created 'mydb' and this becomes the new currently active 'mydb' file.

So if the internet connection drops out during the download, there will be no harm done.  The currently active 'mydb' will not be deleted until a complete 'mydb.gz' is available.

This is based on the HDD models, so I'm not sure how the diskless B2 64G model behaves, but it should follow this process.  I would need to convert a B2 2TB into a B2 64G to prove this, so it might be a while before I will get a chance to try this.

Regards,

Peter.

[keithG]

Hi Peter

Thanks for the information, it allayed my worries. I downloaded 'Get mydb' database this morning. My test Configuration, details and observations are listed below for your information

B2 Configuration 32G 'SD only', SSD and sata interface card removed.

SD card with 13.Nov.18 software plus web upgrade to 22.Mar.21

info - Capacity 30Gb, 24.95Gb used (1,560 tracks, 73 Albums)

with WiFi off, 4 cd's were identified that were not recognised by the 'original' internal cddb.

with wifi on -

selected 'settings - maintenance - get mydb' - download ~7 mins & unzipping ~6 mins, then success displayed.

with wifi off -

3 of the 4 selected cd's above are now recognised.

Observations:

- The red 'activity' led stopped flashing after ~5 mins (standby timeout ?) gave a few worrying minutes.

- On the info page the 'capacity' had dropped from 30Gb to 29.2Gb and 'used' had increased from 24.95Gb to 26.5Gb. Selecting 'Freespace' made no difference to these values. The album & track count remained the same.

- I would not advise selecting 'get mydb' with less than 5Gb free storage.

Reboot the B2 -

info - 'Capacity' returned to 30Gg but 'Used' remained at 26.5Gb. It appears that the cddb file is added to the 'music' partition on an SD only unit.

A fresh 'backup to C' confirmed that all tracks remained present, with album, track & byte counts matched.

Cloned the OS to another SD card with 'SD to USB C' (256Gb target in this case). The original cddb on the SD was not copied over, probably deleted or the software has re-directed it to the music partition which is not copied over. No cd's were recognised with the target SD fitted to the B2.

Reverted B2 back to HDD configuraton with the 32Gb SD card (plus downloaded cddb). The new cddb is recognised in both 'use SD' and 'use HDD' modes.

So in summary the 'Get mydb' downloads to the SD 'music' partition in an 'SD only' unit and when a HDD is added the database remains available in both 'use HDD' and use 'SD' modes'. 

I'll try the same sequence of events (when time permits) with a HDD fitted but selecting 'use SD' before selecting 'get mydb', my prediction is that this would also direct the cddb to the SD card...

Hope this all makes sense... Does this relate to downloading 'get mydb' in HDD configuration and 'use HDD' selected.

Regards

Keith G 

[keithG]

Hi Peter

I selected ‘Get mydb’ while in ‘use SD’ mode. (neither SDD or HDD had  an cddb - result from 256Gb in previous post). The info in ‘use SD’ and 'use HDD' modes remained the same, despite selecting free space and scan disc.

I removed the B2 HDD and confirmed that there is no evidence of cddb file, the total content is accounted for in the music, playlists, b2db, b2rootfs.tar.gz & settings.

Inspection of the SD confirmed that 'mydb' was in the ‘music’ partition (1.48Gb base 1024), despite no change to the data on the B2 ‘info’ display to confirm this. 'mydb is available in both 'use SD' and ''use HDD' modes.

Regards

Keith G