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Forum Discussion
Selective Sync should moderate it's disk IO activity on large hierarchies
On MacOS Ventura, Dropbox 182.4.6427. Selective Sync monopolizes the disk IO when removing a hierarchy from the sync. With a sufficiently large folder, the reads from Selective Sync reading and hashing the contained files to verify their online counterpart before removal completely overwhelms all other disk activity. Maximum read rate is maintained until all files are confirmed.
- Jay
Dropbox Staff
Hi paul_skinner, thanks for bringing this to our attention.
If you're removing a folder from the selective sync menu, this means that it's deleting the local version of the folder, which would be handled by the OS.
Are you referring to adding a folder back to your Dropbox folder?
This will help me to assist further!
I am REMOVING a folder from Selective Sync.
This is not accomplished by Dropbox telling the finder to just delete the folder. First dropbox builds a list of contained files/folders and sorts them by file size, small to large, then reads each one, hashes it and compares the hash with the online version. If it matches it is deleted. The occurs regardless of the sync status of my Dropbox. If Dropbox is fully synced I would think it could be simply deleted, but this function was coded to reconfirm each file. I do not have any issue with the safety / thoroughness being practiced here. I just want better behavior from DB regarding monopolizing the drive IO while doing this.
Disk activity indicates massive continuous READS from the DB drive even if no other activity except the Selective Sync folder removal are occurring.
This may not be easily testable / reproducible without LARGE folders synced. 150GB folder removes just fine. I can watch the "downloading 2500 files" rapidly drop and complete. It still monopolizes the drive IO with reads, but completes quickly enough. Using selective sync to remove a 16 TB folder ruins my whole day.
I've also asked if there is ANY method to remove files from the local store that does NOT read the entire contents of the folder. There is not according to the techs I spoke with.
- Jay
Thanks for the info. We appreciate the feedback on this matter. We take all comments into consideration when improving the Dropbox site and services.
Currently, there isn't another method to activate the selective sync feature. If you want to prevent files from syncing, there is the method to ignore files from syncing to the Dropbox folder, meaning that they remain on your machine and any changes made to files on the computer or the site won't sync to each other.
