Arch Linux

cemsbr

Member

From: Brazil

Registered: 2008-05-03

Posts: 111

Website

Slow docker

I'm running docker in a btrfs over dm-crypt. I tried disabling autodefrag and using noatime (still using lzo compression), switching disk scheduler, chattr +C in subvolumes and conatainers folders, but had no effect. For example, uninstalling ipython and its dependencies in Ubuntu 16.04 took 33s. Timings:

$ docker run -it ubuntu /bin/bash
# apt update
# time apt install -y ipython
real    0m41.255s
user    0m3.818s
sys     0m3.475s
# time apt autoremove -y ipython
real    0m33.190s
user    0m1.484s
sys     0m2.970s

$ uname -a
Linux kytos 4.11.6-1-ARCH #1 SMP PREEMPT Sat Jun 17 08:19:42 CEST 2017 x86_64 GNU/Linux
$ docker info
Containers: 3
 Running: 1
 Paused: 0
 Stopped: 2
Images: 4
Server Version: 17.05.0-ce
Storage Driver: btrfs
 Build Version: Btrfs v4.10.2
 Library Version: 102
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins: 
 Volume: local
 Network: bridge host macvlan null overlay
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 9048e5e50717ea4497b757314bad98ea3763c145
runc version: 9c2d8d184e5da67c95d601382adf14862e4f2228
init version: 949e6fa
Security Options:
 seccomp
  Profile: default
Kernel Version: 4.11.6-1-ARCH
Operating System: Arch Linux
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 7.702GiB
Name: kytos
ID: DDJP:4WC3:THZY:2C2S:WKSR:MMA7:ONNZ:ADGM:GLFE:WQJE:Q5OF:56AD
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Username: cemsbr
Registry: https://index.docker.io/v1/
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

firecat53

Member

From: Lake Stevens, WA, USA

Registered: 2007-05-14

Posts: 1,542

Website

Re: Slow docker

I have a similar setup on my laptop (full disk btrfs on dm-crypt, on an SSD)

/etc/fstab:

/dev/mapper/root        /               btrfs           rw,noatime,compress=lzo,ssd,discard,space_cache,autodefrag,inode_cache  0 0

For the same scenario, ipython installed in about 24 sec (including download time), and uninstalled in about 8 sec.

apt autoremove -y ipython
....
real    0m8.291s                                               
user    0m1.563s                  
sys     0m1.120s

Is your btrfs filesystem getting full? Running scrub regularly? If you can, delete /var/lib/docker and restart docker to try again. Check if you have a large number of subvolumes.

Just guessing here. I run docker on 2 Arch machines (only one also with dm-crypt) without any troubles <knock on wood>

Scott

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