[PVE-User] pve-zsync + borgbackup "changed size" discrepancy

[devzero at web.de]

to answer this:

https://mail.python.org/pipermail/borgbackup/2019q1/001280.html


> Gesendet: Freitag, 01. März 2019 um 12:50 Uhr
> Von: devzero at web.de
> An: pve-user at pve.proxmox.com
> Betreff: [PVE-User] pve-zsync + borgbackup "changed size" discrepancy
>
> hi,
> i'm syncing a zfs dataset with pve-zsync to another proxmox host and also do backup with borg-backup of the same
> dataset via temporary backup snapshot.
> 
> i have shutdown all VMs on the dataset and only leave a single win10 vm up and running.
> 
> i see a huge discrepancy between what pve-zsync is reporting as "changed data" to be synced to the other node
> and what borbackup is reporting regarding backup growth (see below). ("deduplicated size" means: this is the size
> the archive grew after the data has been checksummed, deduplicated and compressed)
> 
> does anybody have a clue why this differs by "roughly a power of 10" ?
> 
> is pve-zsync estimation wrong ?
> is borgbackup "overhead" so big when backing up large single qcow2 files ?
> 
> regards
> roland
> 
> pve-zsync estimated size:
> total estimated size is 1.79M
> total estimated size is 22.9M
> total estimated size is 13.5M
> total estimated size is 24.4M
> total estimated size is 22.9M
> total estimated size is 24.1M
> total estimated size is 10.2M
> total estimated size is 20.9M
> total estimated size is 81.0M
> total estimated size is 53.3M
> total estimated size is 10.8M
> total estimated size is 14.1M
> total estimated size is 10.9M
> total estimated size is 189M
> total estimated size is 29.0M
> total estimated size is 21.2M
> total estimated size is 14.1M
> total estimated size is 13.1M
> total estimated size is 11.0M
> total estimated size is 14.1M
> total estimated size is 11.3M
> total estimated size is 14.9M
> total estimated size is 10.5M
> total estimated size is 14.2M
> total estimated size is 20.4M
> 
> BorgBackup growth
>                        Original size      Compressed size    Deduplicated size
> This archive:              111.69 GB             19.86 GB             95.31 MB
> This archive:              111.69 GB             19.86 GB            197.58 MB
> This archive:              111.69 GB             19.86 GB            119.40 MB
> This archive:              111.69 GB             19.86 GB            138.81 MB
> This archive:              111.69 GB             19.86 GB            180.30 MB
> This archive:              111.69 GB             19.86 GB            205.75 MB
> This archive:              111.69 GB             19.86 GB             76.22 MB
> This archive:              111.69 GB             19.86 GB            159.60 MB
> This archive:              111.69 GB             19.86 GB            636.18 MB
> This archive:              111.69 GB             19.86 GB            413.14 MB
> This archive:              111.69 GB             19.86 GB             83.86 MB
> This archive:              111.69 GB             19.86 GB            122.86 MB
> This archive:              111.69 GB             19.86 GB            108.17 MB
> This archive:              111.69 GB             19.86 GB            153.89 MB
> This archive:              111.69 GB             19.89 GB            946.72 MB
> This archive:              111.69 GB             19.89 GB            126.48 MB
> This archive:              111.69 GB             19.89 GB            139.23 MB
> This archive:              111.69 GB             19.89 GB            113.23 MB
> This archive:              111.69 GB             19.89 GB             67.53 MB
> This archive:              111.69 GB             19.89 GB            129.25 MB
> This archive:              111.69 GB             19.89 GB             74.28 MB
> This archive:              111.69 GB             19.89 GB            110.28 MB
> This archive:              111.69 GB             19.89 GB             80.15 MB
> This archive:              111.69 GB             19.89 GB             92.86 MB
> This archive:              111.69 GB             19.89 GB            160.57 MB
> _______________________________________________
> pve-user mailing list
> pve-user at pve.proxmox.com
> https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user
>