On Wed, Oct 05, 2016 at 03:06:58PM +1300, Richard Hector wrote: > Can you elaborate on the performance issues? I'm using dirvish for my > maildirs (dovecot imap server), without noticeable problems.
I don't know whether dirvish does something to improve matters, but with hard link trees, if you have lots of little files (such as Maildir archives of busy mailing lists like LKML), the amount of space consumed by the file system metadata to represent the trees is very high, getting towards the size used for the files themselves. This is compounded on some filesystems (the ext family amongst them) that only ever increase the amount of space for storing dirent metadata, never decrease it, so if you have a Maildir which has high churn, and you move from having a large amount of mail to a small amount, the storage allocated for metadata for the directory will remain large. On a low-powered device like an embedded NAS, performing operations like delete (such as during a backup rotation) on a large hardlink tree can be very slow and require a lot of CPU time. > My current challenge is to back up windows boxes - if I can get rsync to > work (maybe DeltaCopy? Not sure if that will work how I want), I guess > I'll be stuck doing a local rsync of a smbfs mount ... unless someone > has a better suggestion. Windows has an rsync-like tool called Robocopy, but I'd skip straight to Backup PC for backing up Windows machines. -- Jonathan Dowland Please do not CC me, I am subscribed to the list.
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