On 7/23/14, 2:18 PM, Miles Fidelman via illumos-discuss wrote: > Saso Kiselkov via illumos-discuss wrote: >> On 7/23/14, 1:38 PM, Miles Fidelman via illumos-discuss wrote: >>> Saso Kiselkov wrote: >>>> On 7/23/14, 12:57 PM, Miles Fidelman via illumos-discuss wrote: >>>>> Hi Folks, >>>>> >>>>> Is there anything like DRBD or HAST for illumos? Seems like ZFS + >>>>> DRBD >>>>> would be really sweet for high availability clusters - but so far, >>>>> none >>>>> of the pieces are together in one place. >>>>> >>>>> Trying to get to a small cluster w/ Xen+ZFS+HA >>>>> >>>>> ZFS: illumos, FreeBSD, not really stable anywhere else >>>>> Replication: DRBD for Linux, HAST for BSD*, ??? for illumos >>>>> Xen: Linux, NetBSD >>>>> >>>>> Sigh... >>>> AFAIK there's no native remote block-level synchronous replication >>>> solution for Illumos. >>>> >>>> For async replication, incremental snapshots are the way to go. Just >>>> transfer an incremental snapshot every 30-60s. They're relatively >>>> inexpensive and robust, so pool corruption doesn't immediately get >>>> propagated to the replication pair. >>>> >>>> For sync replication I personally use SAS fabrics and mirrored pools >>>> (conceptually, this is essentially what sync replication does, only >>>> over >>>> a special protocol). Passive SAS cabling can run 3m (so rack-to-rack is >>>> possible) and 20m with active cabling (room-to-room even). If longer >>>> links are needed I'd opt for iSCSI. At Nexenta we've got some early >>>> stuff in ZFS that allows us to prioritize reads & writes to mirror >>>> sides, but it's still pretty new and not battle proven. >>>> >>>> I know these are conceptually not exactly the same as DRBD or HAST, but >>>> functionally it's identical. >>>> >>> Thanks for the model. It's kind of overkill for what we're doing - tiny >>> (4-node) cluster, mostly for development, but we run mail and a list >>> manager in a HA-configuration. >>> >>> The basic stack, right now is: >>> >>> VM (Debian Dom1) >>> DRBD >>> LVM >>> software raid >>> Xen (Debian Linux Dom0) >>> >>> Pretty stable, except... if you're following the Linux world, and the >>> stuff w/ systemd (moving lots of core functions into a monolithic blob) >>> - instead of upgrading Linux, I've been seriously looking at migrating >>> to either a BSD or Solaris based stack. Complicated by having a couple >>> of older machines in our cluster that don't have hardware virtualization >>> extensions. >>> >>> Kind of what I'd LIKE to do is: >>> >>> VM (illumos if I can get all the mail, list, antivirus, etc. to run, >>> otherwise Linux) >>> <something like DRBD or HAST> >>> ZFS (exported ZVOL) >>> Xen (illumos-based Dom0) >>> >>> Can't seem to find a full set of comparable software in either the BSD* >>> or illumos worlds. Sigh... >> For the VM stuff, I'd recommend having a look at SmartOS. Sure, you >> won't be able to do KVM on machines without HVM and EPT support, but >> you'll still be able to run zones on there and run your mail (latest >> postfix, postgrey, etc.), AV (latest clamav), web (latest apache, nginx, >> ruby, php, etc.), DB (latest mysql, postgres, etc.) and other stuff. All >> of these are available in packaged form from the Joyent repos, so no >> need to compile from source. And to insure disaster recovery, unless you >> need sync replication (and judging by your description of your >> environment as "tiny"), run an incremental zfs send/recv job and be done >> with it - if need be, you can even run it every 10s. >> > > SmartOS looks really sweet. > > I'm just quite sure I'm ready to give up: > Xen - I rely prefer it's overall architecture and environment to any of > the other virtualization solutions > synchronous replication > The combination makes failover a no-brainer. With zfs send/receive, > somethings going to get out of whack, sooner or later - good for > backups, not so good for HA failover.
If you think sync replication absolves you of the need to do regular backups, you are so in for a bad a surprise down the road. -- Saso ------------------------------------------- illumos-discuss Archives: https://www.listbox.com/member/archive/182180/=now RSS Feed: https://www.listbox.com/member/archive/rss/182180/21175430-2e6923be Modify Your Subscription: https://www.listbox.com/member/?member_id=21175430&id_secret=21175430-6a77cda4 Powered by Listbox: http://www.listbox.com
