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Need Advice For New Install and Migration From Exchange

Posted: Thu Nov 15, 2018 1:44 pm
by keshmekesh
We are planning to migrate our Exchage server to Zimbra. On exchange we have currently total 10k users and 2000(mobile+web app) online users in day about 20k mail transfers(incoming+outgoing).

1.We are deciding to setup multihost instalation. For our setup we need some advice.
Our current plans are =>

--------- -------------
| MTA | | MailStore |
| Proxy | <-----> | zmlogger | ... more mailstores when needed
| LDAP | | etc . |
--------- --------------
MTA server 16 GB ram 8 CPU Mailstore Server 32GB ram 8CPU and enough disk size. We ll install all on virtual servers.


we ll setup all roles on 2 servers and using like that.

or give some advices about planning pls :)

Re: Need Advice For New Install and Migration From Exchange

Posted: Thu Nov 15, 2018 3:07 pm
by DualBoot

MTA server 16 GB ram 8 CPU

From my point of view it is overkill. You should split into at least 2 MTA (which give redundancy) like that :
zimbra MTA = 2 CPU 2 Go RAM
MTA can be CPU killer due to amavis, but you will be able to adjust it by adding core or socket after the installation without re-calibrate Zimbra (like JVM or MySQL).

For the store 4 CPU and 12-16 Go should do the job.


Re: Need Advice For New Install and Migration From Exchange

Posted: Thu Nov 15, 2018 3:41 pm
by pup_seba

For 10K users with that amount of mail (i'm guessing after spam is filtered), I would suggest this conf:
- 2 Zimbra LDAP in mmr configuration. Both Zimbra with 2vCPU and 8GB of RAM
- 3 Stores. Try to spread the accounts so the same volume of info is among the servers. 4vCPU should be enough. For RAM, consider 6GB only for the JVM, + 4 for the OS + 6GB (initially) for the innodb_buffer of mariadb. Once you have all the info in the new servers, check the real size of your mariadb and size the buffer accordingly. Try not to have more than 2TB of info in each will just make you have a big db in there and will also slow any backup/restore operation way too much imho. Always scale horizontally if you can.
- 1 or 2 MTA/Proxy servers, depending in if you have the possiblity to use a loadbalancer in front of them or not. 4vCPU and 8GB of RAM is enough, even if you consider using a 1GB of ramdisk for amavis later on.
- 1 Server for Zimbra DOCs if you are planning on using that functionality. 2vCPUs and 8GB of RAM should be more than enough.

If you are running in a virtual env, phisical memory will usually be consumed if it is being used. So for LDAPs and MTAs, which will usually be way below the 8GB of consumed memory, is not like you are consuming physical memory and you are in a "safe" zone in regards of Zimbra support as you are sizing you VMs with the minimum ram required for zimbra which is 8GB.

Re: Need Advice For New Install and Migration From Exchange

Posted: Fri Nov 16, 2018 8:37 am
by keshmekesh
Thanks for all advices.
We decided to have 2 MTA-Proxy-Ldap and min 3 DataStores
For MTA servers 2-4vCPU and 8 GB ram and for DataStores 2vCPU 8GB ram

we want to install LDAP servers(with mmr) in mta and proxy is it a good option or we need to seperate ldap servers ?
We ll keep to use our active directory servers so we wont focus on zimbra LDAP servers for directory services (this ldap servers are going to use only by zimbra)

And also read at some forums making dynamic mail groups for more than 10k users is a problem in zimbra. What are u using for managing huge dynamic mail lists ?