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festive

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Quick System mirroring under Solaris 8 between different arch(s)

Greetings fellow Solaris people.

I have a question of approach...

The question is the BEST method based on simplicity and speed that will do the following:

I need to Mirror (filesystems etc etc) the following:
romulus:a sparc 10 with 2 disks, a tape drive and cdrom
remus:  a sparc 5 with 1 disk, and a cdrom drive.

the systems are both running Solaris 8 - but the sparc 5 is not at the same patchlevel etc (which is one of the reasons to do this)

obviously the hostname, ip etc need to be preserved/restored - but apart from that all should be the same.

the two machines are limited to a 10mbit connection (by virtue of standard interfaces.

I have been musing over the rhost type option for ufsdump etc, dd,cpio,tar,ufsdump,rdist to tape etc etc.

Preferably the process needs to be a PUSH from the sparc10.

Kind Regards,
Festive
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yuzh

You can use rsync (they are almost the same between, it only do the difference) to do the job.

You can download it from:
http://sunfreeware.com/

If you are going to give it a try, please remember to put all the hostname ip related file in your excluding file.

eg:


     /etc/nodename    
     /etc/hostname.interface    (eg hostname.le0 )
     /etc//etc/nsswitch.conf
     /etc/resolv.conf      
     /etc/defaultdomain  
     /etc/defaultrouter      
     /etc/inet/networks            
     /etc/inet/netmasks            
     /etc/n/etc/net/ticots/hosts          
     /etc/ticlts/hosts            
     /etc/net/ticotsord/hosts      

   once you install rsync, do a man rsync to find out the usage.



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ASKER

Thanks for your comment - I will wait for the other experts to weigh-in their opinions.

You will need to be a little more specific. ie command line options for this to be of use to me (I appreciate the file list)

Also - I will need to know which end is to execute what, and whether this will work - ie for all files (as the systems are quite a bit out of sync at present and different HW platforms)
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yuzh

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Why do you not just apply the required patches?  

I would download the patch file from Sun, burn it onto a cd, then apply it to both machines (in single user mode).  

Last time I did a sparc-5 this way it took a few hours.  Can you afford the downtime?  Sync'ing 2 machines may seem elegant, but I prefer the simpler approach of just adding the patches.  

Is the tape drive internal, or external?  If it is external, or if you can borrow one, then another option would be to backup the sparc-10 and restore to the sparc-5 (after backing up the sparc-5 first, of course!)
A small comment on the rsync option - you might want to run this on top of SSH instead or rsh, as SSH is more secure.
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ASKER

blowfish:

thanks for your input.

there are a few reasons why the mirroring is desirable:
1) Non-patch content needs to be mirrored
2) to reduce bandwidth requirements (charged by the mb)
3) to make the process fully automated with no manual intervention.

the tape drive is external - but attached to a production system, but the total volume of the prod system is only 6gb and I would propose to do the mirroring each night (when the systems are at minimal load).

Kind regards,
Festive
Blowfish:

First, the Sparc 5 architecture is different from the Sparc 10 (5 has CPU on board, while 10 as CPU cards).  So using a copy of the installation from one machine to the other won't work.

Couple of years back, we had a problem on a Sparc 10.  We took out the disk, put it in a disk box (the interface inside the machines are different) and connected it to a Sparc 20 and it worked because the 10 and 20 have an architecture that is about the same (CPU cards).  But, one day we had installed a brand new Sparc 5, we tried the disk in a Sparc 20 and it never worked, because of the difference in architecture.

So your backup solution wouldn't work (unless I'm wrong, but I dout it this time).

So an rsync or rdist solution would be better, or even an
Install server that could double as a Patch server.

Cheers,

Richard
That's why to keep an excluding file list. Some time ago, One of my Ultra 10 box CPU dead, I endup have to put it in one of my Ultra 5 box for a few days, it works find. I have also try to mv system from an Ultra 1 to Ultra 10, not a straight forward move, have to  get some of the files from the original Ultra 10 box.

You might end up have to keep th and the mount table as well if you do sync the files on the fly. When you have to
move the HD to the other box, you can always force the system to rebuild the kernel to make it work.
What is the goal of the mirror?  DR, system sync or other?

As for files to exclude, it is easier to identify non-OS dependant files and binaries.  If this can not be done, than user data and binaries have been tightly integrated into the system, preventing easy seperation.

A thought, if this is for standard backups, and a DR solution, organizing or standardizing the filesystem, using NFS mounted binaries, appropreiate project dirs, etc. simplifies the task of rebuilding the machine when that becomes necessary.

For instance, a jumpstart server with the appropreiate configuration (pre and post install scripts), patches, etc could be used to reimage and configure a system to replace a failed unit.  Then use rdist or rsync to copy the information back to the system.  In an SUN only environment, I would use rdist.  However, I lean towards rsync becuase I no longer work in that type of environment.  

Hope that helps
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ASKER

Thanks all for your suggestions.

They are (as always) of the highest quality.

I have decided to go with the rsync option, as I can see no major issues and it would appear the simplest most adaptable solution.

Kind Regards,
Festive
This type of mirroring is usefull (for a Server with a lot of applications installed, and take a lot of time to config). Let's say incase the HD in the Sparc 10 is dead (sorry festive), you can move the HD from the Sparc 5 to the Sparc 10 to make it up and running in a few minutes.
(in the worst case, you only need to change the flat files in the excluding list, and than run an upgrade install on top of it, and you down have to worry about to reconfig the applications)

Use an installation server, + rdist + post-installation-scripts some config files is very handly for workstation. (I use it for installing new work station, and sometime for repairing systems), but it will take more time than the mirroring approach to get a system going again.
You might need to excluding your sendmail config file (if one of the box is a mail sever, and the other one is not)
/etc/mail/sendmail.cf

and whatever aliase files you have under /etc/mail.

festive, thanks for your grading.