Slow rc.conf_mount_ro on APU with CF card



  • I have been travelling around for a few months and have now got back to having a real APU system running 2.2 to play with. I notice that it is slow doing /etc/rc.conf_mount_ro (user symptom is that it takes about 20 seconds to respond to pressing Save when making config changes in the webGUI)
    The APU has a nice new CF card in it, so I do not expect it is running out of write cycles just yet.
    This was an issue on Alix when 2.1 was being developed.
    Do others have this problem?
    Is there a patch that was made to 2.1/FreeBSD8.3 that also needs to be applied to 2.2/FreeBSD10?


  • Rebel Alliance Developer Netgate

    CF? In an APU? Connected how?

    Or do you mean SD card?



  • My mistake - too many years typing CF! Yes, I mean SD card.


  • Rebel Alliance Developer Netgate

    It's pretty quick for me on an ALIX with a CF, and usually I could reproduce it there when it was an issue before.

    Did this start happening on a certain snapshot?

    What sort of times are you seeing?



  • I've just setup a new APU system:

    2.2-BETA (i386)
    built on Mon Oct 06 03:16:41 CDT 2014

    time /etc/rc.conf_mount_rw
    0.160u 0.056s 0:00.60 35.0%    3420+289k 0+30io 0pf+0w
    time /etc/rc.conf_mount_ro
    0.180u 0.111s 0:36.79 0.7%      2481+242k 0+747io 0pf+0w



  • I just updated my APU with SD card to:
    2.2-BETA (amd64)
    built on Tue Oct 07 21:35:10 CDT 2014
    FreeBSD 10.1-RC1

    And here are the timings for RW and RO mount:

    [2.2-BETA][root@apu22.localdomain]/root(4): time /etc/rc.conf_mount_rw
    0.148u 0.062s 0:00.22 90.9%     4097+328k 0+30io 0pf+0w
    [2.2-BETA][root@apu22.localdomain]/root(5): time /etc/rc.conf_mount_ro
    0.146u 0.277s 0:35.52 1.1%      2012+253k 0+2441io 0pf+0w
    [2.2-BETA][root@apu22.localdomain]/root(6): time /etc/rc.conf_mount_rw
    0.162u 0.046s 0:00.21 95.2%     4097+328k 0+30io 0pf+0w
    [2.2-BETA][root@apu22.localdomain]/root(7): time /etc/rc.conf_mount_ro
    0.106u 0.313s 0:34.67 1.1%      2012+249k 0+2441io 0pf+0w
    [2.2-BETA][root@apu22.localdomain]/root(8): time /etc/rc.conf_mount_rw
    0.152u 0.056s 0:00.21 95.2%     3933+309k 0+30io 0pf+0w
    [2.2-BETA][root@apu22.localdomain]/root(9): time /etc/rc.conf_mount_ro
    0.111u 0.309s 0:34.51 1.1%      2006+233k 0+2424io 0pf+0w
    
    

    Around 30+ seconds to go back to RO.

    @obk has a similar timing and is using the i386 image - so we both get the same result regardless of the architecture.

    Can some others contribute sample timings so we can see if this is a widespread issue?



  • Here is a sample of an APU with SD card system on 2.1.5, exactly the same hardware as the test system above:
    2.1.5-RELEASE (amd64)
    built on Mon Aug 25 07:44:45 EDT 2014
    FreeBSD 8.3-RELEASE-p16

    [2.1.5-RELEASE][root@xxx]/home/admin.phil(15): time /etc/rc.conf_mount_rw
    0.201u 0.067s 0:00.27 96.2%     3477+686k 0+27io 0pf+0w
    [2.1.5-RELEASE][root@xxx]/home/admin.phil(16): time /etc/rc.conf_mount_ro
    0.206u 0.066s 0:00.33 78.7%     3582+704k 0+42io 0pf+0w
    
    

    The mount RO takes only 330ms and is consistent when repeated.


  • Rebel Alliance Developer Netgate

    Started a ticket, https://redmine.pfsense.org/issues/3918, to track it.

    The older patch probably needs updated and brought back in.



  • Also having this issue with 2.2 on one of the APU boards. As a bit of a temporary workaround to make things bearable to use you can check the box for the system to leave the media always mounted as RW in the nanoBSD menu.



  • i put the old sysctl there.
    Test it and let us know after upgrading to latest snapshot.



  • 2.2-BETA (amd64)
    built on Tue Oct 14 17:37:25 CDT 2014
    FreeBSD 10.1-RC2

    [2.2-BETA][admin@apu22.localdomain]/root(8): time /etc/rc.conf_mount_rw
    0.158u 0.055s 0:00.22 90.9%     4097+328k 0+30io 0pf+0w
    [2.2-BETA][admin@apu22.localdomain]/root(9): time /etc/rc.conf_mount_ro
    0.153u 0.069s 0:00.44 47.7%     4053+331k 0+43io 0pf+0w
    [2.2-BETA][admin@apu22.localdomain]/root(10): time /etc/rc.conf_mount_rw
    0.146u 0.069s 0:00.22 90.9%     4254+334k 0+30io 0pf+0w
    [2.2-BETA][admin@apu22.localdomain]/root(11): time /etc/rc.conf_mount_ro
    0.174u 0.047s 0:00.44 47.7%     3898+319k 0+42io 0pf+0w
    
    

    My APU is feeling much happier now, thanks.


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