Re: Jessie (8.0) slow to boot

From	Darac Marjal <mailinglist@darac.org.uk>
Newsgroups	linux.debian.user
Subject	Re: Jessie (8.0) slow to boot
Date	2016-08-31 17:10 +0200
Message-ID	<scfjk-40K-49@gated-at.bofh.it> (permalink)
References	<scewW-3rZ-13@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Aug 31, 2016 at 09:16:00AM -0500, Richard Owlett wrote:
>I have Jessie installed on a desktop and a laptop. They both take 
>about 105-110 seconds to boot. Squeeze on the desktop takes ~15 
>seconds to boot.
>
>Most of the delay seems to be in something that states approximately
>"A start job is running for dev-disk-by\x2duuid?????.device (ttttt}"
>Where ????? is a long alphanumeric string
>      ttttt is a timer display
>That is followed by two message identified as "Warning" in bright 
>yellow.[they pass by to fast to read].
>
>What's going on?

UUID is considered to be the most reliable way to locate a disk, given 
modern kernels' asynchronous device discovery. It is no longer 
considered "safe" to assume that /dev/sda is your main hard drive. On 
small systems, it probably won't change, but if you have several drives, 
they can start at different times, and the order in which they get 
enumerated may change. Therefore, Linux now tends to refer to disks by 
UUID (Universally Unique IDentifier). The boot process now involves 
various methods for finding that UUID and, as you see above, waiting 
some considerable time for the device to appear (the device might be 
dependant on another host, or it might be on a relatively slow bus such 
as USB or SCSI-1 etc)

Now, there are a number of reasons why you might get the messages above, 
but one common 'gotcha' is that systemd is more strict about what 
devices are needed to boot the system. Basically, systemd assumes that, 
if you've listed a device in /etc/fstab and you've not told it 
otherwise, then that device is necessary for the system to boot. The two 
main ways to disabuse it of this notion are to either add the option 
"noauto", in which case the device will not get mounted at boot but you 
can still invoke "mount /path/to/mountpoint" once the system is up, or 
else you can add the option "nofail" which tells systemd that a failure 
to mount the device should not lead to a failure of the service (and 
thus booting can continue).

Another reason, and this may well be something you're hitting, is that 
the UUID doesn't match any devices on the system. UUIDs are, typically, 
created by mkfs (or mkswap). If you reformat a partition, the UUID will 
probably change, and your /etc/fstab might be pointing to the old 
device. If, say, you create filesystems and restore a backup to them, 
then /etc/fstab can be pointing to UUIDs which no longer exist; if 
that's the case, then consider using LABEL=something in /etc/fstab 
instead. UUIDs are reliable, but they are computer generated. Sometimes 
a maintainer-generated identifier is better.

>Are the messages that scroll past preserved anywhere?
>TIA
>
>

-- 
For more information, please reread.

Thread

Jessie (8.0) slow to boot Richard Owlett <rowlett@cloud85.net> - 2016-08-31 16:20 +0200
  Re: Jessie (8.0) slow to boot Greg Wooledge <wooledg@eeg.ccf.org> - 2016-08-31 16:30 +0200
    Re: Jessie (8.0) slow to boot Richard Owlett <rowlett@cloud85.net> - 2016-08-31 17:00 +0200
      Re: Jessie (8.0) slow to boot Greg Wooledge <wooledg@eeg.ccf.org> - 2016-08-31 17:10 +0200
        Re: Jessie (8.0) slow to boot Greg Wooledge <wooledg@eeg.ccf.org> - 2016-08-31 18:10 +0200
        Re: Jessie (8.0) slow to boot Richard Owlett <rowlett@cloud85.net> - 2016-08-31 18:10 +0200
      Re: Jessie (8.0) slow to boot Felix Miata <mrmazda@earthlink.net> - 2016-08-31 17:50 +0200
        Re: Jessie (8.0) slow to boot Richard Owlett <rowlett@cloud85.net> - 2016-08-31 18:30 +0200
          Re: Jessie (8.0) slow to boot Felix Miata <mrmazda@earthlink.net> - 2016-08-31 18:50 +0200
            Re: Jessie (8.0) slow to boot Richard Owlett <rowlett@cloud85.net> - 2016-09-01 13:00 +0200
              Re: Jessie (8.0) slow to boot Gene Heskett <gheskett@shentel.net> - 2016-09-01 16:00 +0200
          Re: Jessie (8.0) slow to boot David Wright <deblis@lionunicorn.co.uk> - 2016-08-31 20:50 +0200
          Problem source verified -Re: Jessie (8.0) slow to boot Richard Owlett <rowlett@cloud85.net> - 2016-09-01 14:10 +0200
            Re: Problem source verified -Re: Jessie (8.0) slow to boot Darac Marjal <mailinglist@darac.org.uk> - 2016-09-01 14:20 +0200
              Re: Problem source verified -Re: Jessie (8.0) slow to boot David Wright <deblis@lionunicorn.co.uk> - 2016-09-01 16:50 +0200
                Re: Problem source verified -Re: Jessie (8.0) slow to boot Michael Biebl <biebl@debian.org> - 2016-09-02 09:50 +0200
                Re: Problem source verified -Re: Jessie (8.0) slow to boot David Wright <deblis@lionunicorn.co.uk> - 2016-09-02 17:40 +0200
                Re: Problem source verified -Re: Jessie (8.0) slow to boot Nicolas George <george@nsup.org> - 2016-09-02 17:50 +0200
                Re: Problem source verified -Re: Jessie (8.0) slow to boot David Wright <deblis@lionunicorn.co.uk> - 2016-09-02 21:40 +0200
                Re: Problem source verified -Re: Jessie (8.0) slow to boot Curt <curty@free.fr> - 2016-09-02 18:30 +0200
            Re: Problem source verified -Re: Jessie (8.0) slow to boot claude juif <claude.juif@gmail.com> - 2016-09-01 16:00 +0200
              Re: Problem source verified -Re: Jessie (8.0) slow to boot Richard Owlett <rowlett@cloud85.net> - 2016-09-02 15:10 +0200
    Re: Jessie (8.0) slow to boot Dominic Knight <dominicknight@gmx.com> - 2016-08-31 18:20 +0200
  Re: Jessie (8.0) slow to boot Darac Marjal <mailinglist@darac.org.uk> - 2016-08-31 17:10 +0200
  Re: Jessie (8.0) slow to boot Alan McConnell <alan@his.com> - 2016-08-31 20:50 +0200
    Re: Jessie (8.0) slow to boot Darac Marjal <mailinglist@darac.org.uk> - 2016-09-01 11:20 +0200

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