I create a new thread, because the issue is not really the same, but i copy 
here the thread that made me jump into the list.

My issue is not really that it waits before starting copying, but a general 
performance issue, specially when there are multiple rsync running at the same 

Here is my situation :
I have multiple clients (around 20) with users and i want to rsync their home 
dirs with my server to keep a copy of their local files.
On the server, files are hosted on a iSCSI volume (on a Thecus RAID) where i 
never had any performance issue before.

When there is only one client, i have no real performance issues. In a few 
minutes, even with a very large number of files (some users have up to ), the 
sync is done if there are not too many changed files.
But when there are 3 or more rsync at the same time, all rsync become very very 
slow and can take a few hours to complete.

Here are my options :

/usr/local/bin/rsync3 --rsync-path=/usr/local/bin/rsync3 -aHXxvE --stats 
--numeric-ids --delete-excluded --delete-before --human-readable —rsh="ssh -T 
-c aes128-ctr -o Compression=no -x" -z 
--skip-compress=gz/bz2/jpg/jpeg/ogg/mp3/mp4/mov/avi/vmdk/vmem --inplace 
--chmod=u+w --timeout=60 —exclude=‘Caches' —exclude=‘SyncService' 
—exclude=‘.FileSync' —exclude=‘IMAP*' —exclude=‘.Trash' —exclude='Saved 
Application State' —exclude='Autosave Information' 
--exclude-from=/Users/pabittan/.UserSync/exclude-list --max-size=1000M 
/Users/pabittan/ xserve.local.fftir:./

Here is the version i use (self compiled) : 
$ /usr/local/bin/rsync3 --version
rsync  version 3.1.2-jsp  protocol version 31
Copyright (C) 1996-2015 by Andrew Tridgell, Wayne Davison, and others.
Web site: http://rsync.samba.org/
    64-bit files, 64-bit inums, 64-bit timestamps, 64-bit long ints,
    socketpairs, hardlinks, symlinks, IPv6, batchfiles, inplace,
    append, ACLs, xattrs, iconv, symtimes, no prealloc, file-flags

I had to put in place a sort of queue to not allow more than 4 simultaneous 
rsync to be sure they run at least once a day each. Even limiting to 4 rsync 
makes some wait hours before starting a backup.

I’m open to any help to improve perfs. (i have put my whole script calling 
rsync on github : https://github.com/jpiel/UserSync 
<https://github.com/jpiel/UserSync> )

I checked, CPU is not under pressure, each rsync instance use between 2 and 5% 
CPU. The whole CPU usage 30%.
I also checked network, and it’s not either an issue.
Disk usage doesn’t seem to be at a high load either… (peak at 300 IO/sec)

> Le 20 mars 2018 à 13:00, rsync-requ...@lists.samba.org a écrit :
> De: Kevin Korb <k...@sanitarium.net <mailto:k...@sanitarium.net>>
> Objet: Rép : Very slow to start sync with millions of directories and files
> Date: 19 mars 2018 à 15:33:31 UTC+1
> À: rsync@lists.samba.org <mailto:rsync@lists.samba.org>
> The performance of rsync with a huge number of files is greatly
> determined by every option you are using.  So, what is your whole
> command line?
> On 03/19/2018 09:05 AM, Bráulio Bhavamitra via rsync wrote:
>> Hi all,
>> I'm using rsync 3 to copy all files from one disk to another. The files
>> were writen by Minio, an S3 compatible opensource backend.
>> The number of files is dozens of millions, almost each of them within
>> its own directory.
>> Rsync takes a long time, when not several hours, to even start syncing
>> files. I already see a few reasons:
>> - it first create all directories to put files in, that could be done
>> along with the sync
>> - it needs to generate the list of all files before starting, and cannot
>> start syncing and keep the list generation in a different thread.
>> Cheers,
>> bráulio
> -- 
> ~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,
>       Kevin Korb                      Phone:    (407) 252-6853
>       Systems Administrator           Internet:
>       FutureQuest, Inc.               ke...@futurequest.net 
> <mailto:ke...@futurequest.net>  (work)
>       Orlando, Florida                k...@sanitarium.net 
> <mailto:k...@sanitarium.net> (personal)
>       Web page:                       http://www.sanitarium.net/ 
> <http://www.sanitarium.net/>
>       PGP public key available on web site.
> ~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,

Jayce Piel   —    jayce.p...@gmail.com  --  0616762431
   Responsable Informatique F.F.Tir

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