Date: Fri, 18 May 2012 09:34:44 +0800 From: Marcelo Araujo <araujobsdport@gmail.com> To: Adam Nowacki <nowakpl@platinum.linux.pl> Cc: freebsd-fs@freebsd.org Subject: Re: Mirror of Raidz for data reliability Message-ID: <CAOfEmZgAr4Q8knKaf0=6YJwqK1KqspzxiMt%2BF6XKuxSFUg_v=A@mail.gmail.com> In-Reply-To: <4FB4E1CC.8030501@platinum.linux.pl> References: <CAOfEmZh8v5xbQqkJJ7ZKkan7Ho0FPNrXJ95S1WRpioDXVG6P7w@mail.gmail.com> <20120515102206.GA53750@psconsult.nl> <CAOfEmZiTkr9Xcj6J4FRBd4FzL1ztgEpytSAUc=wZ8DBJtXsH%2Bg@mail.gmail.com> <CA%2BdUSyrG-RFFjchEYfovbvORVBZNHes9r9MhhGG1d568cO-CwA@mail.gmail.com> <CAOfEmZhtxvNM3kiK5mvTZCxzkTiVWKt97yAudfaxFCnjbANQ0g@mail.gmail.com> <CA%2BdUSyppT%2Bngjn9UXBVW1K0eDa93OB00Rd=TX31brwmAaxNy8w@mail.gmail.com> <CA%2BdUSyraV54L_j01gQaWYCsmNJBOt4-j4OayxiiRfMFO4vJLqg@mail.gmail.com> <4FB4E1CC.8030501@platinum.linux.pl>
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Dear Adam, Yes, you are right! 2012/5/17 Adam Nowacki <nowakpl@platinum.linux.pl> > My understanding of this setup is: > - there are 2 chasis housing disks, each with a 2 port SAS expander, > - there are 2 servers, each with a 2 port SAS HBA (1st port connected to > 1st SAS expander, 2nd port connected to 2nd SAS expander). > > > On 2012-05-17 13:17, George Kontostanos wrote: > >> On Thu, May 17, 2012 at 1:52 PM, George Kontostanos >> <gkontos.mail@gmail.com> wrote: >> >>> On Thu, May 17, 2012 at 3:29 AM, Marcelo Araujo<araujobsdport@gmail.com* >>> *> wrote: >>> >>>> George, >>>> >>>> >>>>> If you have 2 machines then your best bet would be HAST. >>>>> >>>> >>>> >>>> So, why use ETHERNET if my Machine can see both JBOD? >>>> >>> >>> I was under the impression that you are talking about 2 different >>> physical machines. >>> >>> If you are worried about data replication you can always use lagg with >>>>> 2 or more interfaces. >>>>> >>>> >>>> >>>> It is different than data replication. It is data protection. >>>> >>> >>> Storing the same data in 2 different locations is data protection. >>> >>> Regards >>> >>> >> Ok, after reading more carefully your first post I realized what you >> are trying to do. >> >> 2 Machines, 2 different controllers. Yet interconnected. So, in a way >> both machines would be able to see both controllers. >> >> This is very interesting but there are some implications. >> >> 1) Suppose you manage to create a mirror consisted by drives on those >> different controllers. If you reboot machine #1 machine#2 might panic. >> It is not like loosing a drive, here we are loosing a controller. >> >> 2) Both machines have to be online and the pool has to be mounted >> readonly on the standby! You don't want both of them to accidentally >> write at the same pool. >> >> 3) HAST requires tcp to work therefore it is a no go. HAST also works >> in the vdev level. Therefore the resources should not be online on the >> standby server. >> >> Good luck, this is certainly very interesting. >> >> > ______________________________**_________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/**mailman/listinfo/freebsd-fs<http://lists.freebsd.org/mailman/listinfo/freebsd-fs>; > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@**freebsd.org<freebsd-fs-unsubscribe@freebsd.org> > " > -- Marcelo Araujo araujo@FreeBSD.org
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