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File Formats                                          synclist(4)



NAME
     synclist - list of files to be  synchronized  when  changing
     from one boot environment to another

SYNOPSIS
     /etc/lu/synclist

DESCRIPTION
     The synclist file lists files that will be synchronized when
     you  switch  from  one boot environment (BE) to another. The
     file is part of the Live  Upgrade  feature  of  the  Solaris
     Operating  Environment.  See live_upgrade(5) for an overview
     of the Live Upgrade software.

     The synclist file consists of a list of  entries,  with  two
     fields  per entry. The first field is a pathname, the second
     a keyword. The keyword can be one of OVERWRITE,  APPEND,  or
     PREPEND.  The meanings of these keywords is described below.
     synclist accepts comments; a comment is indicated by a  hash
     mark (#) in the first character position on a line.

     The way in which a file is updated is indicated by the  key-
     word in the second field of its synclist entry. All of these
     operations occur upon the first boot of  a  newly  activated
     BE. The keywords have the following semantics:

     OVERWRITE
           Overwrite the contents of a file with the contents  of
           the file of the same name on the previously booted BE.
           Both  directories  and  files  can  be  specified  for
           overwriting. If you specify a directory, every file in
           and beneath the listed directory is subject  to  being
           overwritten.  (Whether an individual file or directory
           is overwritten depends on  the  outcome  of  the  com-
           parison  of file versions, described below.) Following
           an overwrite operation, a file on a  new  BE  has  the
           same date of creation, mode, and ownership as the file
           of the same name on the previously booted BE.

     APPEND
           Append the contents of a file on the previously booted
           BE to the contents of the file of the same name on the
           new BE. Use of APPEND allows for  the  possibility  of
           duplicate  entries  in  a  file. You cannot use APPEND
           with directories. Following  an  append  operation,  a
           file  on  a new BE will have a different modified date
           and time from the same file on the  previously  booted
           BE.  The  mode  and ownership will be the same between
           the two files.

     PREPEND
           Prepend the contents  of  a  file  on  the  previously



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File Formats                                          synclist(4)



           booted BE to the contents of the file of the same name
           on the new BE. Use of PREPEND allows for the possibil-
           ity  of  duplicate  entries  in a file. You cannot use
           PREPEND with directories. Following a  prepend  opera-
           tion,  a  file on a new BE will have a different modi-
           fied date and time from the same file  on  the  previ-
           ously  booted  BE.  The mode and ownership will be the
           same between the two files.

     The second (keyword) field in a synclist entry can be empty,
     in which case the OVERWRITE action is assumed.

     In deciding when to update a file on a newly  activated  BE,
     Live  Upgrade  uses  an  algorithm  illustrated in the table
     below. In the table, "old"  refers  to  a  BE  relinquishing
     activated  status; "new" refers to a newly activated BE. The
     "resulting state" occurs when the new BE is first booted.

     _______________________________________________________________
    | State of File    |  State of File     | Resulting State      |
    |                  |                    |                      |
    |      on Old BE   |       on New BE    |      on New BE       |
    |__________________|____________________|______________________|
    | Unchanged        |  Unchanged         | Not updated          |
    |__________________|____________________|______________________|
    | Updated          |  Unchanged         | Updated              |
    |__________________|____________________|______________________|
    | Unchanged        |  Updated           | Not updated          |
    |__________________|____________________|______________________|
    | Updated          |  Updated           | Conflict Indicated   |
    |__________________|____________________|______________________|


     When a file is updated on both an old and new BE,  as  shown
     in the last row of the table above, Live Upgrade reports the
     conflict and allows you to resolve it.

     Modify the contents of synclist with caution. Adding certain
     files  to  synclist  might  render a BE unbootable. Also, be
     careful in using the file-inclusion and  -exclusion  options
     in  lucreate(1M)  in conjunction with changes you might make
     in synclist. Again, you could render a system unbootable  or
     end up with different results from what you expected.

     Switching BEs among different Solaris Operating  Environment
     marketing  releases  (for  example, from a Solaris 9 BE to a
     Solaris 2.6 BE) requires care. This is  especially  true  if
     you  make  any  modifications to synclist. For example, con-
     sider that the last-active BE contains  Solaris  9  and  you
     want to activate a BE that contains Solaris 2.6. In synclist
     in the Solaris 9 BE, you have added files that  are  present
     in Solaris 9 that are not present in Solaris 2.6 or that are



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File Formats                                          synclist(4)



     no longer compatible with Solaris 2.6. If  you  forced  syn-
     chronization  with the luactivate(1M) -s option, the BE con-
     taining Solaris 2.6 might be synchronized  with  files  that
     might not work under Solaris 2.6.

EXAMPLES
     Example 1: Updating the passwd File

     Consider the following scenario:

     1. You create a BE, named first.

     2. You create a new BE, named second,  using  first  as  the
        source.

     3. You add a new user to first, thereby making  an  addition
        to the passwd file in first.

     4. Using luactivate(1M), you activate second. At this point,
        Live  Upgrade  recognizes  that  the passwd file has been
        updated in first and not in second.

     5. When you boot second for the first  time,  Live  Upgrade,
        directed  by  the  keyword  OVERWRITE in synclist, copies
        passwd from first to second, overwriting the contents  in
        the latter BE.

     The result described above obtains with  any  of  the  files
     associated  with  the  OVERWRITE keyword in synclist. If the
     reverse had occurred-you edited passwd on  second  and  left
     passwd  in first untouched-Live Upgrade would not have modi-
     fied passwd in second when that BE was first booted.

     Example 2: Updating the /var/log/syslog File

     Consider the following scenario:

     1. You create a BE, named first.

     2. You create a new BE, named second,  using  first  as  the
        source.

     3. Logging occurs, adding to the contents of /var/log/syslog
        in first.

     4. Using luactivate(1M), you activate second. At this point,
        Live  Upgrade  recognizes  that  /var/log/syslog has been
        updated in first and not in second.

     5. When you boot second for the first  time,  Live  Upgrade,
        directed  by  the keyword APPEND in synclist, appends the
        contents of /var/log/syslog in first to the same file  in



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File Formats                                          synclist(4)



        second.

     The result described above obtains with  any  of  the  files
     associated  with  the  APPEND  keyword  in  synclist. If the
     reverse had occurred-you changed /var/log/syslog  on  second
     and  left  /var/log/syslog  in  first untouched-Live Upgrade
     would not have modified /var/log/syslog in second when  that
     BE was first booted.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWluu                     |
    |_____________________________|_____________________________|
    | Interface Stability         | Evolving                    |
    |_____________________________|_____________________________|


SEE ALSO
     luactivate(1M),  lucreate(1M),  lumake(1M),   attributes(5),
     live_upgrade(5)






























SunOS 5.9            Last change: 6 Aug 2003                    4