SUMMARY: Re: DST Patch for Solaris 6 and 7

From: D G Teed <>
Date: Sat Feb 10 2007 - 02:51:13 EST
Here is the best information I've gleaned on the topic.

Sun has an info page at covering
their products.  You might want to check with any database
vendors to see if their software is impacted by the changes.

Solaris 8 and up are covered by Sun's patches and don't
need to worry about these details as much.

First of all, you need to be aware of your timezone.  Try
'echo $TZ' or look at how it is set in /etc/default/init .

If your timezone is a format like EST5EDT, you are using
POSIX timezone format.  This requires a patched libc to have
the new DST rules.  You will not get this from working with
the source timezone files.  If you are running Solaris 6 or 7
and your $TZ looks like a POSIX format , you might want to consider
switching to the other format.  Again, you should consult with
any database vendor or other significant software on the impact
of changing the timezone format.

If your timezone looks something like "Canada/Atlantic" or
then you are using a Olson format.  This only requires changes
under /usr/share/lib/zoneinfo .

If you use the patch from Terix
it only updates zoneinfo files, not libc.  Basically Terix
is providing the same thing as this brief howto
emailed to me by Michael Imrick:

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =

Download data from:

gunzip -c tzdata2007a.tar.gz | tar xf -

for i in africa antarctica asia australasia etcetera europe northamerica
pacificnew southamerica backward
  echo $i
  zic $i

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =

It is important to include 'backward' last in this list, or else it can't
some of the things it needs to link.  I didn't try the Terix patch
but I'd imagine it would be fine for those who prefer patch commands.

There are a couple of ways to test.  You can change the date and watch.
That is too low tech for me.  I trust the system.  DST isn't new after all.

Query the zoneinfo with whatever your $TZ is (which you may want to change
if you have been using POSIX format).

zdump -v $TZ | grep 2007

For my part of the world, this returns these dates:
Canada/Atlantic  Sat Feb 10 07:37:39 2007 UTC = Sat Feb 10 03:37:39 2007 AST
Canada/Atlantic  Sun Mar 11 05:59:59 2007 UTC = Sun Mar 11 01:59:59 2007 AST
Canada/Atlantic  Sun Mar 11 06:00:00 2007 UTC = Sun Mar 11 03:00:00 2007 ADT
Canada/Atlantic  Sun Nov  4 04:59:59 2007 UTC = Sun Nov  4 01:59:59 2007 ADT
Canada/Atlantic  Sun Nov  4 05:00:00 2007 UTC = Sun Nov  4 01:00:00 2007 AST

If you see April and October dates (for North America anyway), then test
with another timezone and consider your options if you find a better one.

Some software is sensitive to the timezone changes.  At least when libc
is included in the patch from Sun, I've seen services fail like apache
and ssh.  It is something that really should have a reboot immediately
after applying the change, or schedule it for your usual maintenance window.

Thanks for the replies everyone.  I am truly impressed with the sunmanager
user community.


--Donald Teed
sunmanagers mailing list
Received on Mon Feb 12 10:13:50 2007

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