I'm telling you that they (the Linux and BSD solutions you mentioned) are not real HA. Real general purpose HA requires shared memory clustering and custom kernels. This is not commodity stuff. I believe Oracle and EMC both have expensive offerings here. Not sure who else. But you probably don't have that requirement.
If you want a block level replication that can be done. Not even difficult modulo edge case handling. But is that what you want? Your stated app is not really an HA requirement. Mail is EASY. Hell we did this with shared NFS decades ago at Qualcomm. You do need an underlying HA server for your backend. There are numerous ways to get there both commercial and non commercial. I am not in a position to consult on this for you myself but I'm sure there are people here who are willing to help you design an illumos solution to your application and availability needs. First start with the requirements. Sent from my iPhone > On Dec 23, 2014, at 7:09 PM, Miles Fidelman via illumos-discuss > <[email protected]> wrote: > > Garrett, you're missing the point. There is a general purpose HA solution for > Linux, and most of one for BSD. There isn't for illumos (well, not a FOSS > one). That's a significant lack. > > > Garrett D'Amore wrote: >> Ha mail just needs an HA filesystem. That isn't hard to achieve. Can even >> spool over NFS though that is kind of painful and possibly risky. A >> distributed filesystem like ceph might work here. Or use a mail server >> backed by a distributed database. That's not postfix but options do exist. >> >> Again solving for this app requirement is probably lots easier than solving >> for the HA requirement in general. >> >> Sent from my iPhone >> >>> On Dec 23, 2014, at 3:03 PM, Miles Fidelman via illumos-discuss >>> <[email protected]> wrote: >>> >>> HA at application level is just fine for most things, but less so for >>> things like mail systems and mailing lists that use the file system for >>> ques in ways that are not all that easy to pick apart. >>> >>> I've been running our postfix infrastructure and sympa mailing list handler >>> (along with the associated antivirus, antispam, dbms, and web server) in a >>> Xen virtual machine, backed by DRBD and Pacemaker for over a decade. It >>> may not be a magic bullet, but it works rather reliably. >>> >>> I have yet to find all the comparable building building blocks for either >>> BSD or illumos. Seems like a lack in the ecosystems to me. >>> >>> Miles Fidelman >>> >>> Garrett D'Amore via illumos-discuss wrote: >>>> HAST would not be hard to do in illumos. But the trick is failure modes. >>>> >>>> In practice you can choose latency or consistency. >>>> >>>> Modern times ha clustering is fine locally with shared storage clusters >>>> using eg shared SAS or iscsi. But you still need something like zfs send >>>> recv for DR. >>>> >>>> There are no silver bullets. If you think your Linux config is one then >>>> you haven't done the full failure analysis. >>>> >>>> Realistically HA is almost always best done at the app level rather than >>>> the OS. Because there is no magic when we're taking about commodity >>>> hardware. >>>> >>>> Sent from my iPhone >>>> >>>>> On Dec 23, 2014, at 2:15 PM, Miles Fidelman via illumos-discuss >>>>> <[email protected]> wrote: >>>>> >>>>> It really is a pain. >>>>> >>>>> In the Linux world, Xen or KVM + DRBD + Pacemaker + CRM gives you a >>>>> relatively painless HA cluster. >>>>> In the BSD world, there's HAST + CARP get you pretty far along the same >>>>> path. >>>>> But there's nothing equivalent in the illumos world (Xen is pretty thin >>>>> too). >>>>> >>>>> Kind of a large gap when it comes to using illumos in any kind of >>>>> production environment. >>>>> >>>>> Miles Fidelmn >>>>> >>>>> -- >>>>> In theory, there is no difference between theory and practice. >>>>> In practice, there is. .... Yogi Berra >>>>> >>>>> >>>>> >>>>> ------------------------------------------- >>>>> illumos-discuss >>>>> Archives: https://www.listbox.com/member/archive/182180/=now >>>>> RSS Feed: >>>>> https://www.listbox.com/member/archive/rss/182180/22003744-9012f59c >>>>> Modify Your Subscription: https://www.listbox.com/member/?&; >>>>> Powered by Listbox: http://www.listbox.com >>>> ------------------------------------------- >>>> illumos-discuss >>>> Archives: https://www.listbox.com/member/archive/182180/=now >>>> RSS Feed: >>>> https://www.listbox.com/member/archive/rss/182180/26374045-77b11078 >>>> Modify Your Subscription: https://www.listbox.com/member/?&; >>>> Powered by Listbox: http://www.listbox.com >>> >>> -- >>> In theory, there is no difference between theory and practice. >>> In practice, there is. .... Yogi Berra >>> >>> >>> >>> ------------------------------------------- >>> illumos-discuss >>> Archives: https://www.listbox.com/member/archive/182180/=now >>> RSS Feed: >>> https://www.listbox.com/member/archive/rss/182180/22003744-9012f59c >>> Modify Your Subscription: https://www.listbox.com/member/?&; >>> Powered by Listbox: http://www.listbox.com > > > -- > In theory, there is no difference between theory and practice. > In practice, there is. .... 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