Extented boot time due to snap

I noticed my boot times almost doubled (55s~) as I installed more snap programs. How can I troubleshoot this?

Output from systemd-analyze critical-chain and systemd-analyze --user critical-chain https://termbin.com/52ci

Snap version: snap 2.51.7 snapd 2.51.7 series 16 ubuntu 20.04 kernel 5.4.0-88-generic

snapd should not hold back any other services from starting (not even snaps) so even the fact that snapd takes 21s to start should not affect your boot speed … I see another 20s for journal-flush service, that indicates you got rather huge logs … is your disk filled with giant logs (in /var/log/journal) by chance ?

journalctl --disk-usage outputs 120.0M

does sudo du -hcs /var/log/ agree ?

I tried cleaning up with journalctl --vacuum-time=1d, now my boot time has decreased to 42s, but still far from what I used to get before, 28s

output from sudo du -hcs

/var/log/ 23M /var/log 23M total

new output from systemd-analyze critical-chain Screenshot_20211005_143514

I guess from here on we need someone from the snapd team to give more debugging hints, pushing the output of journalcl -b to termbin might be helpful …


24s to start snapd is very long indeed. Can you provide the output of the following commands:

  • snap debug timings --all --startup ifacemgr
  • snap changes
  • systemd-analyze blame

snap debug timings --all --startup ifacemgr

2021/10/05 18:11:22.964576 main.go:176: description of prepare-image's "<target-dir>" is lowercase in locale "pt_BR": "o directório de destino"
    erro: cannot find startup: ifacemgr

snap changes

 2021/10/05 18:08:26.575087 main.go:176: description of prepare-image's "<target-dir>" is lowercase in locale "pt_BR": "o directório de destino"
    ID   Estado  Gerado              Pronto              Resumo
    132  Done    ontem às 22:49 -03  ontem às 22:49 -03  Reverter o snap "citra-emu"
    133  Done    ontem às 22:55 -03  ontem às 22:55 -03  Actualizar o snap "citra-emu"
    134  Done    hoje às 10:56 -03   hoje às 10:57 -03   Remover o snap "citra-emu"
    135  Done    hoje às 10:58 -03   hoje às 10:59 -03   Instalar snap "citra-emu"
    136  Done    hoje às 12:30 -03   hoje às 12:32 -03   Instalar snap "kdenlive" from "candidate" channel
    137  Done    hoje às 12:37 -03   hoje às 12:37 -03   Actualizar o snap "kdenlive" do canal "latest/edge"
    138  Done    hoje às 12:41 -03   hoje às 12:41 -03   Remover o snap "kdenlive"

and systemd-analyze blame

28.377s dev-sda5.device                                                    
24.963s snapd.service                                                      
19.862s udisks2.service                                                    
17.109s dev-loop28.device                                                  
16.798s dev-loop20.device                                                  
16.748s dev-loop16.device                                                  
16.667s dev-loop27.device                                                  
16.497s dev-loop24.device                                                  
16.440s dev-loop25.device                                                  
16.222s dev-loop22.device                                                  
15.736s dev-loop18.device                                                  
15.691s NetworkManager.service                                             
15.514s dev-loop21.device                                                  
15.407s dev-loop26.device                                                  
15.342s polkit.service                                                     
15.290s dev-loop13.device                                                  
15.289s dev-loop12.device                                                  
15.288s dev-loop19.device                                                  
15.283s dev-loop17.device                                                  
15.282s dev-loop15.device                                                  
15.238s dev-loop23.device                                                  
14.700s systemd-logind.service                                             
13.321s dev-loop3.device                                                   
12.953s dev-loop14.device                                                  
12.825s dev-loop8.device                                                   
12.521s dev-loop2.device                                                   
11.434s dev-loop10.device                                                  
11.005s dev-loop1.device                                                   
10.788s smartmontools.service                                              
10.665s dev-loop9.device                                                   
10.440s dev-loop7.device                                                   
10.119s dev-loop11.device                                                  
 9.055s dev-loop6.device                                                   
 7.118s dev-loop5.device                                                   
 7.039s dev-loop4.device                                                   
 6.602s ModemManager.service                                               
 6.038s dev-loop0.device                                                   
 4.445s systemd-udevd.service                                              
 4.369s rsyslog.service                                                    
 3.997s systemd-modules-load.service                                       
 3.995s ufw.service                                                        
 3.933s e2scrub_reap.service                                               
 3.810s systemd-journal-flush.service                                      
 3.373s packagekit.service                                                 
 3.312s alsa-restore.service                                               
 2.639s apparmor.service                                                   
 2.354s systemd-resolved.service                                           
 2.190s snapd.seeded.service                                               
 2.181s grub-common.service                                                
 2.002s snap-bare-5.mount                                                  
 1.941s snap-citra\x2demu-134.mount                                        
 1.769s kerneloops.service                                                 
 1.694s snap-core-11606.mount                                              
 1.653s snap-core-11743.mount                                              
 1.507s snap-core18-2074.mount                                             
 1.477s snap-core18-2128.mount                                             
 1.446s snapd.apparmor.service                                             
 1.261s snap-core20-1026.mount                                             
 1.224s snap-core20-1081.mount                                             
 1.133s snap-dolphin\x2demulator-507.mount                                 
 1.112s grub-initrd-fallback.service                                       
 1.095s snap-dolphin\x2demulator-526.mount                                 
 1.042s snap-ffsend-47.mount                                               
 1.025s snap-ffsend-48.mount                                               
  935ms colord.service                                                     
  838ms snap-freecad-22.mount                                              
  828ms systemd-sysusers.service                                           
  801ms snap-gnome\x2d3\x2d28\x2d1804-145.mount                            
  796ms systemd-tmpfiles-setup-dev.service                                 
  775ms snap-gnome\x2d3\x2d28\x2d1804-161.mount                            
  729ms snap-gnome\x2d3\x2d34\x2d1804-72.mount                             
  695ms snap-gnome\x2d3\x2d38\x2d2004-76.mount                             
  682ms ua-messaging.service                                               
  680ms systemd-tmpfiles-setup.service                                     
  672ms plymouth-read-write.service                                        
  655ms systemd-sysctl.service                                             
  626ms snap-gtk\x2dcommon\x2dthemes-1515.mount                            
  624ms sysstat.service                                                    
  563ms swapfile.swap                                                      
  546ms snap-gtk\x2dcommon\x2dthemes-1519.mount                            
  538ms systemd-random-seed.service                                        
  471ms snap-kde\x2dframeworks\x2d5-27.mount                               
  437ms snap-snapd-13170.mount                                             
  411ms snap-snapd-12883.mount                                             
  403ms snap-telegram\x2ddesktop-3119.mount                                
  370ms snap-riseup\x2dvpn-172.mount                                       
  361ms snap-telegram\x2ddesktop-3149.mount                                
  351ms snap-kde\x2dframeworks\x2d5\x2dqt\x2d5\x2d15\x2d3\x2dcore20-4.mount
  350ms keyboard-setup.service                                             
  349ms systemd-udev-trigger.service                                       
  344ms systemd-timesyncd.service                                          
  315ms snap-riseup\x2dvpn-168.mount                                       
  296ms snap-kde\x2dframeworks\x2d5\x2dqt\x2d5\x2d15\x2d3\x2dcore20-5.mount
  247ms snap-kde\x2dframeworks\x2d5\x2dqt\x2d5\x2d15\x2dcore20-14.mount    
  245ms upower.service                                                     
  243ms console-setup.service                                              
  192ms user@1000.service                                                  
  143ms systemd-journald.service                                           
  125ms dev-hugepages.mount                                                
  125ms dev-mqueue.mount                                                   
  124ms sys-kernel-debug.mount                                             
  124ms kmod-static-nodes.service                                          
  124ms sys-kernel-tracing.mount                                           
  101ms systemd-remount-fs.service                                         
   99ms sddm.service                                                       
   89ms plymouth-start.service                                             
   86ms rtkit-daemon.service                                               
   81ms systemd-update-utmp.service                                        
   63ms setvtrgb.service                                                   
   41ms plymouth-quit.service                                              
   34ms systemd-user-sessions.service                                      
   12ms user-runtime-dir@1000.service                                      
    5ms sys-fs-fuse-connections.mount                                      
    5ms sys-kernel-config.mount                                            
    5ms systemd-update-utmp-runlevel.service                               
    1ms snapd.socket

I see, the loopback device setup takes very long for some reason. I’ve tried to analyze it a while ago in another topic Snapd causing lengthy boot time? but it looked like the problem is in the kernel. This is probably running from a spinning hard disk drive, isn’t it? Anyway, I don’t think that’s a fair justification for this being slow.

Another observation is that on my Arch and openSUSE boxes, snapd.service does not appear in the critical chain. In fact, it’s not really wanted by the multi-user.target. While on 20.04 cloud image, it’s clearly enabled and in the critical path. You can try running systemctl disable snapd.service snapd.seeded.service, which will prevent snapd from being started during boot, but will keep the snapd.socket around, so snap commands will work normally. A downside is that automatic updates will not be applied until the snapd daemon has been started.

doing that really improved my boot time to what i used to get, yes it’s a wd hdd; despite the downside, this really sort things out