Backup is very slow


I have installed urbackup on a windows 2019 server. Clients are windows 2021r2, 2016, 2019 and send backup trought internet connexion (hight speed connexion). Backups are very slow or seems to be blocked like on the print screen.
have you any idea?



Have you looked at previous “slow” threads? E.g. Very Slow Client Backup (50 KBit/s)

I have read this before. I don’t think this is a problem of pause. No cable problem because this is trought internet (2 cloud server)
server file : NTFS, RAID 5 software
antivirus exclusion is OK
I test with and without background priority
Disabling new congestion control algorithms : i don’t know to found this option
disabling TCP offloading : i tried on backup server

I test with an other backup program (veeam agent) and there is no problem


It looked exactly the same on my FreeBSD server not long ago. Turned out to be a HDD controller and/or cabling issue.
After hardware upgrade it works like a charm again.

Or what came out recently (with WD reds). One might inadvertendly be using a SMR disk and it is busy reorganizing itself after a large number of random writes.