How to speed up rsync?

Question

I'm running rsync to sync a directory onto my external USB HDD. It's about 150 gigs of data. 50000+ files I would guess.

It's running it's first sync at the moment, but its copying files at a rate of only 1-5 MB/s. That seems incredibly slow for a USB 2.0 enclosure. There are no other transfers happening on the drive either.

Here are the options I used:

rsync -avz --progress /mysourcefolder /mytargetfolder

I'm running Ubuntu Server 9.10.

Answer 1

For the first sync just use

cp -a  /mysourcefolder /mytargetfolder

rsync only adds overhead when the destination is empty.

also.. the -z option is probably killing your performance, you shouldn't be using it if you are not transfering data over a slow link.

Answer 2

If you're using rsync with a fast network or disk to disk in the same machine,

not using compression -z

and using --inplace

speeds it up to the performance of the harddrives or network

compression uses lots of CPU

not using inplace makes the harddrive thrash alot (it uses a temp file before creating the final)

compression & not using inplace is better for doing it over the internet (slow network)

NEW: Be aware of the destination... if there is NTFS "compression" enabled... this severely slows down large files (I'd say 200MB+) rsync almost seems stalled, it's caused by this.

Answer 3

Use the -W option. This disables delta/diff comparisons. When the file time/sizes differ, rsync copies the whole file.

Also remove the -z option. This is only useful for compressing network traffic.

Now rsync should be as fast as cp.

Answer 4

First - the number of files in this case is going to be a major factor. It's an average size of 3MB each. There's probably an io bottleneck influencing the speed in the OP's case. More here - that's a pretty dry read, but the cover picture is worth it.

So, using rsync to copy to an empty directory? Here are some ways to speed it up:

1. No -z - definitely don't use -z as in the OP.
2. --no-compress might speed you up. This could have the biggest impact... my test was 13,000 files, total size 200MB, and using rsync 3.1.3. I synced to a different partition on the same internal SSD drive. With --no-compress, I get 18 MBps, and without it I get 15 MBps. cp, by the way, gets 16 MBps. That's a much smaller average file size though. Also - I can't find any documentation for --no-compress. I learned about it from this post on stackexchange.com.
3. -W to copy files whole - always use this if you don't want it to compare differences; never mind that the point of rsync is to compare differences and only update the changes.
4. -S to handle sparse files well - can't hurt if you don't have sparse files.
5. --exclude-from or something similar to exclude files you might not need will cut down the time, but it won't increase your transfer speed.
6. It's possible if you send the output to a file like this rsync -a /source /destination >/somewhere/rsync.out 2>/somewhere/rsync.err - the first > basically prints a file with all the stuff you would normally see, and the 2> refers to error messages.
7. Finally, running multiple instances of rsync for different parts of your transfer could be a big help.

My command would be:

rsync -avAXEWSlHh /source /destination --no-compress --info=progress2 --dry-run

If all looked well, I'd delete "--dry-run" and let it go. A, X, and E cover extended attributes and permissions not covered by -a, l is for soft links, H is for hard links, and h is for human readable.

Updating an already synced directory on a USB drive, or the same drive, or over a network, will all require different rsync commands to maximize transfer speed.

Bonus - here's the rsync man page, and if you want to test your hard drive speed, bonnie++ is a good option, and for your network speed, try iperf.

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*The post is almost ten years old, but search engines sure like it, and I keep seeing it. It's a good question, and I don't think the top answer to "how to speed up rsync" should be "use cp instead."

Answer 5

You don't say what size distribution your files have. If there are many small files then this will reduce overall transfer rate by increasing head movement latency in both the source and destination drives as the tool opens new files and the OS keeps directory entries and other metadata (such as the filesystem's journal if you are using meta-data journaling like ext3/ext4 and NTFS do by default) up to date during the transfer. A file copy proces will only "get into its stride" for larger objects, when a simple bulk transfer is happening.

Answer 6

Avoid

• -z/--compress: compression will only load up the CPU as the transfer isn't over a network but over RAM.
• --append-verify: resume an interrupted transfer. This sounds like a good idea, but it has the dangerous failure case: any destination file the same size (or greater) than the source will be IGNORED. Also, it checksums the whole file at the end, meaning no significant speed up over --no-whole-file while adding a dangerous failure case.

Use

• -S/--sparse: turn sequences of nulls into sparse blocks
• --partial or -P which is --partial --progress: save any partially transferred files for future resuming. Note: files won't have a temporary name, so ensure that nothing else is expecting to use the destination until the whole copy has completed.
• --no-whole-file so that anything that needs to be resent uses delta transfer. Reading half of a partially transferred file is often much quicker than writing it again.
• --inplace to avoid file copy (but only if nothing is reading the destination until the whole transfer completes)

Answer 7

You definitely want to give rclone a try. This thing is crazy fast :

$ tree /usr [...] 26105 directories, 293208 files

$ sudo rclone sync /usr /home/fred/temp -P -L --transfers 64

Transferred: 17.929G / 17.929 GBytes, 100%, 165.692 MBytes/s, ETA 0s Errors: 75 (retrying may help) Checks: 691078 / 691078, 100% Transferred: 345539 / 345539, 100% Elapsed time: 1m50.8s

This is a local copy from and to a LITEONIT LCS-256 (256GB) SSD.

You can add --ignore-checksum on the first run to make it even more faster.