Results 1 to 10 of 13

Thread: Shared Storage space for MailStore or building High Availabiltiy

Hybrid View

  1. #1
    Join Date
    Sep 2011
    Posts
    256
    Rep Power
    4

    Default Shared Storage space for MailStore or building High Availabiltiy

    Hi Folks,

    I am trying to configure HA MailBox server with the help of external Load balancer and due to the budget constraint we are evaluating the simpler ways to configure the scenario rather than investing on SAN at this moment.

    We are evaluatiing NFS storage space where two MBOX server would share common /opt/zimbra/message and /opt/zimbra/index. Or thinking to go with DRBD. Please let me know if NFS can work well in this scenario? Can we share the same data store with two servers and create the high availability?

    Just would like to know the forum's opinion on the same. Also, how can we build High Available Zimbra environment in Geographically dispersed locations and/or with Two ISPs?

  2. #2
    Join Date
    Sep 2008
    Location
    Latvia
    Posts
    165
    Rep Power
    7

    Default

    I am trying to configure HA MailBox server with the help of external Load balancer and due to the budget constraint we are evaluating the simpler ways to configure the scenario rather than investing on SAN at this moment.
    I'd still suggest to investigate at least decent SAN solution, as often people hours turn out to be more expensive, rather look for decent automation implementation. Although, it adds some layer of complexity any way.

    We are evaluatiing NFS storage space where two MBOX server would share common /opt/zimbra/message and /opt/zimbra/index. Or thinking to go with DRBD. Please let me know if NFS can work well in this scenario? Can we share the same data store with two servers and create the high availability?
    This forum is quite full with DRBD and HA discussions, although, you have to count on some consequences and work overhead (more details below). Actually it depends on what you want to achieve. Here is a good step-by-step discussion on DRBD implementation. http://www.zimbra.com/forums/adminis...rbd-howto.html and another one http://www.zimbra.com/forums/adminis...mbra-drbd.html

    As per Zimbra wiki, there is recommendation to avoid NFS storages, but I must say, that it all depends on actual configuration. Still, you have to cope with potential file locking, thus thinking about some kind of cluster file system, to be clean.

    If you think of geographically dispersed locations, this probably would not be a SAN issue, as you mention budget constraints.

    Just would like to know the forum's opinion on the same. Also, how can we build High Available Zimbra environment in Geographically dispersed locations and/or with Two ISPs?
    Please take in mind, that best practice asks to keep all ZCS servers within the same versions, to eliminate additional issues that may rise in case of troubleshooting. At least major ones. But I managed to link two different versions together (had an issue with poxy and static js/css files). The biggest pitfall here from terms of usability, is in fact, that all ZCS servers still communicate between themselves, especially when finding LDAP for user authentication and authorization, and if these servers are located in really wide area (say one in EU, one in US), you have to count on significant network latency while LDAP discovery & authentication process completes. It would be more wise, to spread these servers because of user location, not because of load balancing, or the other way, one session might be fast, another - slow. Consider LDAP slave implementation on remote servers, to gain increase for auth process.

    DRBD

    DRBD was working well in my former deployment, but I decided to go HA beyond Zimbra servers - on hypervizer level. Supported way of DRBD is Hot/Cold solution, which sync disk block devices (another option is to look at Ceph or GlusterFS - have not tried them, but recommended to look at from High Availability | www.hastexo.com). You may sync all /opt/zimbra folder. The main problem, if it suites you, is that when HA discovers, that main master server is down, it launches virtual IP migration and boots Zimbra on slave server (yes, Zimbra does not run on both servers, as DRBD for that time didn't support active/active solution). Taking in mind this, in my case it took about 2 minutes, to fully load Zimbra server and recover operations. So this is not hot snap in way. You may sync data over internet too (dealing with security kept in mind), but in some cases if net connection is poor, it might not be 1:1 sync of servers.

    Planning your HA infrastructure, keep in mind, that you have to upgrade servers too, and potentially with minimal downtime. So it would be wise to find out things regarding your chosen solution.

  3. #3
    Join Date
    Sep 2011
    Posts
    256
    Rep Power
    4

    Default

    I see so NFS would not be an good option and investing on descent SAN would be an fair idea.

    I am trying to achieve HA at LAN as well as at WAN level. Or trying to set up DR site and evaluating option. What clues you guys can provide at WAN level.
    Adding two MTA can be an option but then how can I have configuration of Site A is replicated to Site B.

    Would appreciate if you can forward me any good docs you might have in this regards.

  4. #4
    Join Date
    Sep 2011
    Posts
    256
    Rep Power
    4

    Default

    Further to that, I was searching through forum/wiki about setting up backup MX server for just accepting mails until the primary server comes up. But didnt find any good article how can one build a backup MX using zimbra.

    Has anyone every configured this scenario? If so kindly share the document with us.

  5. #5
    phoenix is offline Zimbra Consultant & Moderator
    Join Date
    Sep 2005
    Location
    Vannes, France
    Posts
    23,587
    Rep Power
    58

    Default

    Quote Originally Posted by blason View Post
    Further to that, I was searching through forum/wiki about setting up backup MX server for just accepting mails until the primary server comes up. But didnt find any good article how can one build a backup MX using zimbra.
    You'd do that the same as you would for any Postfix server - there's tons of articles on the web. I would, however, recommend against setting up your own backup server. A backup MX is a hot target for spammers and you'd be better using a professional service for that, you could get that server as an add-on to another service such as DNS hosting. I use EasyDNS for my DNS and they provide a full backup MX that will forward mail to your server when it's back on-line (after a failure) and they retain the mail for up-to five days.
    Regards


    Bill


    Acompli: A new adventure for Co-Founder KevinH.

  6. #6
    Join Date
    Sep 2011
    Posts
    256
    Rep Power
    4

    Default

    Thanks Bill need to explore that option as well.

    Further to that as I stated earlier what options can you recommend to set up zimbra in a geographical dispersed locations with HA? Two MX entries with one backup as we discussed? The main concern is how can we sync up MailStore? Though I agree it wont happen in real time and user is definitely gonna loose few mails but that is understood.

    Also even if we somehow migrate to other site how can users on Internet use the same A record in their mail client to send mails? Just like imagine this scenario

    SITE A - domain example.com

    MX = mail.example.com 10 [Site A]
    mail1.example.com 20 [Site B]

    if users have configured their mail clients using mail.example.com to receive mail or send mail in case of failure doesn't look possible to have them again configured A record for Site B in their mail clients. That would start syncing up emails all over again. And even if do the trick in DNS and add two A records with same name with RoundRobin or LB mechanism few users will still be reached to site A which is down hence wont be able to download or send any messages.

    Now the only option then I think of is using DNS Global Traffic Manager which can eliminate the A records which are down.

    Am I right? Just wanted to be clear on thought process. Or any other approach you can think of?

Similar Threads

  1. Storage space is getting low
    By aiko in forum Administrators
    Replies: 3
    Last Post: 10-19-2012, 08:40 AM
  2. New hardware/OS/version - shared storage
    By su_A_ve in forum Installation
    Replies: 0
    Last Post: 06-30-2011, 05:41 AM
  3. Extending storage space for Briefcase
    By tenpagyatso in forum Administrators
    Replies: 0
    Last Post: 10-06-2009, 01:03 PM
  4. zimbra failover with shared storage and same ip address
    By twilighthaevhen in forum Administrators
    Replies: 1
    Last Post: 12-08-2008, 11:11 PM
  5. Shared storage and ZCS / load balancing store servers
    By bureado in forum Administrators
    Replies: 0
    Last Post: 08-22-2008, 11:32 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •