** Description changed: [Impact] - autofs service in xenial takes extremely long time since its creating - the directory hierarchy for all direct mounts maps, thus it will take - too long to make all the automount shares available when using autofs - with large direct mappings, customer is complaining about this point. So - we need to backport the following upstream patch. + autofs service in xenial takes extremely long time since it parses the + mount table /etc/mtab in contained_in_local_fs() to determine if the mount + patch would be created on a local file system, that means startup process will read /etc/mtab for every mount, so the performance is extremely low. The customer is complaining about this point, we need to backport the + following upstream patch. https://git.kernel.org/pub/scm/linux/storage/autofs/autofs.git/commit/?id=67e7d613a4b09eeffc57ab44a7acb52027d897b2 + + This fix patch removes contained_in_local_fs, and use fs.f_type in is_remote_fstype() to determine if the mount patch would be created on a + local file system instead. [Test Case] * Create an autofs direct mount map with large direct mappings (eg: - more than 20k) + 8k), below is the test script I used. - * Start autofs service to see if it will take too much time to - automount all mappings. + echo "/- auto.direct --timeout 60" >> /etc/auto.master + END=8000 + for i in $(seq 1 $END); do echo $i; echo "/test/samba/test"$i" -fstype=cifs,rw,username=hua,password=password ://192.168.99.169/share" >> /etc/auto.direct; done + + * Start autofs service to see if it will take too much time, below is my + result before/after applying the fix patch. + + root@node1:~# time service autofs start + real 3m5.481s + user 0m0.256s + sys 0m0.080s + root@node1:~# time service autofs start + real 0m0.833s + user 0m0.000s + sys 0m0.004s [Regression Potential] - With this upstream patch, we can avoid creating path compnents on remote - file system unless that file system is the root file system. so - theoretically there is no regression potential. + * We are well aware of the principle of this fix patch - avoiding parsing + the mount table to improve startup time, so seems infinitely better for + all cases. + + * This fix from upstream has been backported into Redhat as well, and both + me and customer have positive test results with automount start timings. [Other Info] - - Redhat [1] also already backported the following patch, see: https://bugzilla.redhat.com/show_bug.cgi?id=1440769 + + * Redhat [1] also already backported the following patch, see: https://bugzilla.redhat.com/show_bug.cgi?id=1440769 + * This mailing list also discussed this problem, see: http://www.spinics.net/lists/autofs/msg01161.html
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1686679 Title: [SRU] Ubuntu16.04 : autofs takes extreamly long with large number of direct maps To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/autofs5/+bug/1686679/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
