I’m currently trying to backup my Windows machine to my urbackup server, that’s using raw copy on write to a BTRFS partition, on an external disk encrypted using LUKS. It is extremely slow. It has been running for about 8 hours and has completed about 65GB out of 550GB.
The backup disk is a WD my passport 1TB: https://www.amazon.co.uk/Western-Digital-Passport-Portable-Type-C/dp/B0792DP87N/ref=psdc_430544031_t3_B01LQQH83I?th=1
The disk is connected to the USB3 slot.
The urbackup server is version 2.4.13, running in docker. The host OS is ubuntu server 20.04, running kernel 5.4. The entire linux OS, urbackupserver included, is on an SSD.
The windows client and server are connected to the same LAN using ethernet.
I have been using urbackup for awhile and have noticed be a little slow (I have 4 clients in total backing up to this disk, there’s ~300 sub volumes on the disk from backing up).
I only recently learnt about using raw COW for image backups so I nuked my previous windows image backups and am running the full raw COW image backup for the first time. It is this backup that is very slow.
Disk is mounted using
iowait seems high, varying from 30% up t0 80% (iostat image included).
There are extended periods where the write speed seems to be almost 0 (see screenshot of activities page)
Things I’ve tried.
- Changing scheduler to BFQ
- Dropping autodefrag from the mount option
- Lowering dirty ratio and background dirty ratio
- Max clients backing up set to 1
Any help is greatly appreciated!