Topic: Should I upgrade from V8?

[david000]

I'm running SME v8 and all's well.

I'm setting up a spare server just in case the one we are using fails and wondered if it's time to move to v9. Any thoughts ?

We're running Roundcube web mail but it would be cool to move to a up to date version of horde.  Other than that I expect our set-up is pretty vanilla. One possibility is to run SME as a domain controller - we're a small business and need to get a handle on user accounts.

On the subject of building a backup server - is it possible to configure two SME boxes and have one mirror the other ?

Thanks in advance.

[guest22]

SME Server 9.x is the latest version and on par with CentOS 6.x. New features and development will target SME Server 9.x 64 bit only. SME Server 8.x is in 'idle' or 'maintenance' mode only, read security fixes until EOL.

In short, all you deploy as new or replacement should be SME Server 9.x

[mercyh]

On the subject of building a backup server - is it possible to configure two SME boxes and have one mirror the other ?

Yes, but maybe not exactly how you are thinking.

I have been running Affa since SME version 7.x and it works great...

This will not be a live mirror but you can set the backup\sync schedule to multiple times a day if needed....
With the "Rise" command, the backup server is cloned as the production server. This process takes less than 30min in most situations.

[david000]

Thank you.

RequestedDeletion, V9 it is then.   The only slight glitch is that I don't think I'm running it on a 64bit box as yet.   I assume that's not an issue - I'm downloading the  i386 iso as I type.

mercyh,  That sounds ideal. The idea is to be able to get a 'spare' box online with the minimum of trouble if need be. I'll check Affa  

[janet]

david000

sme v9 64 bit supports Software Collections which allows multiple versions of the same packages (eg php, mysql) to be installed & utilised by other packages requiring a certain version of dependency rpms.
see

sme v9 32bit only has very limited support for Software Collections mainly from very few external non Red Hat repositories.

If you do not need to run bleeding edge versions of packages then 32 bit should be OK.
It has been said that there is very little speed difference between equivalent machines running 32 or 64 bit server versions.
The need for 64 bit OS will probably depend on how demanding your server requirements are, eg for server side applications etc.
It seems new hardware is mostly 64 bit, so eventually we will all have to go the 64 bit path for sme server OS.

"Rising" an Affa backup server takes about 20 minutes, compared to many hours if restoring from a USB (or similar etc) backup, so speed is Affa's advantage.
IIRC you still need to reinstall contribs so there could be an hour to a few hours of work to get the risen server looking "identical".
Then as well you still need to resolve & fix whatever problem occurred with the main server & restore from your Affa backups, which can still take many hours, so there can still be many hours work required "behind the scenes".

You could in theory just have a basically configured sme standby server (say with users only & some standard data), which you could have running at the flick of a switch (or the plugin of a cable), & that then gives you time to rebuild your main server behind the scenes (eg by fixing the hardware problem, installing the clean OS & restoring from backup). You then need to add in any changes made to the standby server eg incoming mail messages etc.

AFAIK no one has really yet developed a true hot swap standby server "contrib or howto", although the technical bits & pieces seem to exist.

You could also achieve a similar end result by having a highly reliable main server, say with various spare parts, motherboard, power supply, RAM etc, & use a 2 or 3 disk RAID1 (disks in removable caddies or drive slots) with a few spare disks you swap daily & rebuild the array each time.
In the event of a failure you can use one of the removed hard drives to get a degraded array up & running in a few minutes.
The data would be as good (ie current) as at the time of the most recent disk swap. More technically involved, but less work to do to rebuild the server, as all contribs etc are already installed (on the RAID1 drive).

[david000]

Thanks Janet.

We're a small office with just a few account so I would guess not very demanding. I'm downloading the x64 version at the mo and will see if it will take. If it does not i don't think it will be a problem. I doubt that at the moment we need bleeding edge, after all, things are fine on the v8 server which is x32.

My idea is to set up a standby server (exactly the same hardware as the main one) which can be switched in when needed. If I understand correctly, I can create a duplicate SME server complete with the same contribs, and use Affa to schedule back ups from the main to the duplicate. Does it follow that after 'Rising' the new one would match the original, complete with contribs ?

Presumably them, the 'backup' server becomes the new main server and then the problem is fixed the 'old' can then be the reserve ?  This would save having to try and merge or sync the difference between the two email sets.


Another quick question - is there a quick way to check what contribs I have on the existing v8 server ?

[DanB35]

On the 64-bit question, what's your hardware?  If it's at all modern, it should be fine. If you're using an old Pentium II, maybe not.

[janet]

david000

You cannot install the 64 bit OS on 32 bit hardware.
If you are reusing 32 bit hardware, then you need to install from the 32 bit OS media.

Is the main sme server a Domain Controller (DC)., if so it will have machine accounts for the workstation login (which are unique), so you cannot just create a duplicate server, you will have to backup & restore from the main server to the backup server.

Affa will backup the standard sme server backup folders.
It has been a while since I did a Affa rise, but  I think you still need to reinstall contribs (maybe someone else could confirm).
All other data & configuration would match that as at the last backup time.

Presumably them, the 'backup' server becomes the new main server and then the problem is fixed the 'old' can then be the reserve ?  This would save having to try and merge or sync the difference between the two email sets.

Yes & no. Typically you would use the risen server until the main server is repaired & then put the main server back into use, & unrise the backup server. I suggest you do some testing before deploying it. Particularly run through a rise & unrise & see what happens.
See
http://wiki.contribs.org/Affa

Another quick question - is there a quick way to check what contribs I have on the existing v8 server ?

Affa does report installed rpm differences between main server & the backup server.

You can also run
/sbin/e-smith/audittools/newrpms
to get a list of all installed rpms different from the original base version

For other useful diagnostic tools do
ls /sbin/e-smith/audittools

[david000]

janet,

Is the main sme server a Domain Controller (DC)., if so it will have machine accounts for the workstation login (which are unique), so you cannot just create a duplicate server, you will have to backup & restore from the main server to the backup server.

No domain controller at the moment, BUT I do expect that we will go that way in the future. If that's the case then it sounds as if Affa isn't helpful ?

It turns out that the boxes I'm using are x64, so we are good on that front.

Thanks for the commands, just the job.

In the first instance I'll see how the upgrade from 8 to 9 goes (which will also confirm my existing back-up regime) and then see how best to manage having a 'spare'.

 

[janet]

david000

No domain controller at the moment, BUT I do expect that we will go that way in the future. If that's the case then it sounds as if Affa isn't helpful ?

Affa will be OK to use as it backs up the accounts database (which contains the machine accounts).

[guest22]

just as a reference, in a previous decade, I created this http://distro.ibiblio.org/smeserver/contribs/rmitchell/smeserver/howto/High%20Availability%20How-To%20for%20Linux%20Mitel%20SME%20v5.htm


It's old and very outdated, but I wonder if would have covered the requirements...?

[david000]

I spent my Sunday installing and upgrading to v9.  All things considered everything went very smoothly and as advertised. The initial x 64  install went ok as did the eventual restore.

A few comments to help others trying the same thing:
1. To restore back from your backup, the new machine has to be names exactly as the original machine.
2. After rebooting, of course the 'fresh' machine comes up on the same IP as the old....
3. To save the 'fresh' machine collecting mail I 'broke' the gateway IP prior to doing the restore.

I wanted to do the restore offline, form a USB hard drive. However I could not work out how to mount it so had to connect to the Lan and restore from the NAS backup location.

What was impressive was the speed of the restore, maybe 15 or 20 minutes (which sort of makes me wonder if its all there!). 

I also noticed the RAID capability so will double up the drives to get full redundancy.

RequestedDeletion, from what I read it looks like it covers everything. It looks like you do it via serial cables ?  I'll read further later.

janet, Cheers, I'll read up on Affa.  I assume that the usual SME-Backup will create a complete machine, including ibays, but less contribs ? 

One last question - is there anything specific to double check to ensure everything has come over to the 'fresh' V9 machine OK.  I intend to swap it to become the 'Live' Machine next weekend, doing a final restore then.

Thanks again for all your help & suggestions.

   

[janet]

david000

Before doing a backup on the server (immediately prior to switchover to a new server), you should disconnect all workstations (LAN cables or the hub cable), disconnect the WAN cable (to router/Internet), so that no one (external or local or web related) can make changes to the server after the backup is done.

Re speed, that might be OK for a fast server & fast LAN/USB connection with little data, but it is very quick if you have hundereds of Gb on your server hard drive, so ...... I would be checking ?

Did you Verify your backup after it completed ? (to make sure it was a good backup) 

Did you wait for the message Restore is complete, before proceeding (it can take a long time before that message appears even though it seems the restore has finished)

Remember you still have to reinstall Contribs & make sure you use sme 9 versions, & make sure that compatible contribs exist for the essential contribs you already use. Many/most of the sme8 contribs will not work on sme9 due to different path requirements for some items.

You do not tell us how much data (used space) on the drive, or CPU speed/RAM etc of the old & new servers, so it is hard for us to comment.

Re HA Howto.
That is a very old & no longer applicable howto, RequestedDeletion posted it for information only.
DO NOT follow it, but be aware others have attempted to create what you were asking for.
AFAIK Hsing Foo did or suggested some more work using newer software tools (was it Zen ?) but as far as I know dropped his efforts.
If you Google heartbeat & high reliability etc you may see work others have developed or attempted. It is a complex beast so tread carefully, it is not a simple thing to implement (or someone would have already done it for sme server), & the database structure of sme server makes it harder/difficult to achieve.

I assume that the usual SME-Backup will create a complete machine, including ibays, but less contribs ?

Yes, but that is also what Affa will do (just a different underlying procedure)
Here is some additional info re backups, it is worth reading to help you understand what a backup & restore really does in different scenarios
http://wiki.contribs.org/Backup_server_config
in particular
http://wiki.contribs.org/Backup_server_config#Backup_and_Restore_concepts.2C_issues_and_other_information
You may want to add /opt to the backup inclusions, refer wiki Contrib & Howto articles re this

Re restored data.
Yes check everything, users, ibays, data in the ibays, mysql databases, websites, workstation login & user access, contribs working correctlky (after reinstall) & so on. The basic server should be OK from the restore, but add ons & extras & custom templates are where there are likely to be issues, but these can usually be fixed on a "one at at time basis".

I intend to swap it to become the 'Live' Machine next weekend, doing a final restore then.

Final full restore should only be done to a clean fresh installation of sme server from the CD/DVD.  You should not do additional restores over the top of an already done (prior) restore. You can end up with inconsistent folders & data etc.

So reinstall the OS from CD & then restore from the latest backup that you do immediately prior to switchover (maybe overnight if it is big).

Treat what you have done as a test only to prove you are doing it correctly.

[david000]

Hi Janet,

According to 'disk usage' I'm backing up \ restoring about 8gb over a cat5 Lan.

I've installed a new 1tb WD Red (I'm going to double that up before going live) so plenty of space.  It is an older x64 processor with 4Gb RAM.  (Was an XP box).

I did wait for the OK, and it rebooted on the button so I'm pretty sure it's probably OK. It doesn't take much time to verify a backup.

Thanks for the notes on restoring and needing to do a fresh install. That's a shame, but not the end of the world and means that Affa is more appealing.

Point taken on the how to. I'm still very much learning....

Best

David


 

 

[janet]

david000

That amount of data is small so 20 minutes seems OK.