daylight saving, time synchornization on SAN switches

[itai weisman]

Hello,
we have a wide SAN environment, consisted of about ~11 MDS 9000 directors (running SAN OS 3.2.3 and up) and about 50 brocade switches (as IBM Blade centers IO modules), on several fabrics, in a core-edge topology.
can we automate clock changes (twice a year – on daylight saving- anything similar to Unix systems tztab file) and maintain clock synchronization (also on the brocade switches)? this is extremely important, especially when having interoperability issues and other problems that requires analyzing and comparing logs.

[ks6542]

The date and time are specified in the following format, as used on many UNIX systems:

switch:admin> date "mmddHHMMyy"
where:
mm is the month,
dd is the date,
HH is the hour,
MM is minutes,
yy is the year,


If you want to use NTP to synchronize the switch time with a time server please use the tsclockserver and tstimezone command.

tsclockserver command will associate a principal switch with an NTP time server;
the date command then becomes read-only for the rest of the switches in the fabric

[ks6542]

Check the link :

http://www.dectrader.com/docs/set1/ucr_na-CYBAA_RVULC_TE.pdf-1.pdf

Page 58-60 have your answer :)

[itai weisman]

thanks!
do you use these commands on Brocade or Cisco switches?
by using these commands, the time will change even if it is diffrent than the server by more than 5 minutes?

[ks6542 · Accepted solution]

Yes these commands works fine with Brocade and HP branded brocade switches..

First set if instruction is where you can manually set the time using date commands.

If you set NTP time server for your switches it will tune with the time regadrless of any time difference.. :)

[ks6542]

Check these link to configure time settings for cisco mds switches.

http://www.cisco.com/en/US/products/ps5989/products_configuration_guide_chapter09186a0080662d7a.html#wp1509991

http://www.cisco.com/en/US/docs/switches/datacenter/mds9000/sw/4_1/command/reference/CR03_n.html

[krusty]

Hi Itai,

The best way to maintain clock synchronization is the use of an NPT server. Then on switches will all be sync to the same exact time. From there you can set the time zones on the switches to your local time. Both Brocade and Cisco have provided a way to have the correct DST time with the changes last year.

Cisco allows you to set the DST time to the exact time and date, no matter what the gov't changes the your DST to.

clock summer-time PDT 2 sunday march 02:00 1 sunday november 02:00 60 (for USA)

Check with "show clock"

Brocade: tstimezone --interactive

You can check a Brocade switch to see it's current setting using the "tstimezone" command with no switches. If it says

> tstimezone
Time Zone Hour Offset: -8
Time Zone Minute Offset: 0

It is NOT compliant with the new DST. You should see it in this format:

> tstimezone
America/Los_Angeles

Note on the Brocade switches, when you change the timezone to the new format, a reboot IS required for the changes to take affect.

Hope this helps,

Curt