PSIAlt

Most space in email attachments is photos and office documents.

1. This is nothing to do with distributed storage

2. Symlinks are not required to be linked to existing file

3. Symlinks are not atomic

4. You still need to maintain filedb (or how do you resolve which storage contains given file?)

Thanks for your question. In your solution there is some consistency vulnerabilities:

- (Step 1) If "delete service failed" - timeout is a fail? The decrement probably was done, but your app do not see response. In this case you dont know whatever decrement was done really or not. You cannot do re-try with this error (unless you use "magic" =))

- (Step 1) If you do "unmark deleted index" this does not mean it was fixed on disk forever. Your app or even server can shutdown/reboot before you ensure disk write.

- (Step 2) If marking failed you generally cannot rollback. You can try to rollback the decrement, but operation can possibly fail too. On next delete iteration the counter in filedb will be corrupted in this case.

- (Step 3) Indexes become exclusive data owner. If you lose indexes for 1 mailbox somehow - you cannot rely on counters in filedb anymore. So, you cannot do any decrements anymore until full double-side recheck.

- Any bug in any app in this chain can destroy filedb consistency.