Date: Tue, 24 Apr 2018 13:00:21 +0200 From: Karli =?ISO-8859-1?Q?Sj=F6berg?= <karli@inparadise.se> To: Mikhail Zakharov <zmey20000@yahoo.com> Cc: "freebsd-fs@freebsd.org" <freebsd-fs@freebsd.org>, Mike Tancsa <mike@sentex.net> Subject: Re: ctl_isc_lun_sync: Received conflicting HA LUN Message-ID: <1524567621.9560.65.camel@inparadise.se> In-Reply-To: <615DFFBB-239A-4350-B961-FD10D0C9A8DD@yahoo.com> References: <4cb4aa83-bd49-0c20-4e41-c11c682b0570@sentex.net> <F908B78A-DD9B-4204-BA1E-24CE38059ACF@yahoo.com> <1e1e7cd5-0797-c168-fbce-a36edc6a432e@sentex.net> <1524550160.1130.6.camel@inparadise.se> <615DFFBB-239A-4350-B961-FD10D0C9A8DD@yahoo.com>
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--=-x4uETt1Aeoun59RYDAqh Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2018-04-24 at 12:32 +0300, Mikhail Zakharov wrote: > Hi Karli, >=20 > Thank you, I=E2=80=99m just exploring the storage abilities of my preferr= ed > OS - FreeBSD.=20 >=20 > Three nodes are preferable to choose the quorum for sure, but my idea > was not to establish contacts between nodes. Instead of it, BQ uses a > small partition for the =E2=80=9Cquorum=E2=80=9D on the same space where = data volume > is located.=20 Yes, of course. But there=C2=B4s nothing you from having three nodes connected to the same partition and being able to make more accurate choices on when to take over? If one node stops updating stamps, take over. If two nodes stops updating, then the problem is likely network-related and _must not_ take over to avoid split brain. Something like that? /K > And if a node looses access to the quorum it means, it looses access > to the data volume too. Now, BQ runs on both nodes and both BQ > instances write stamps to the quorum partition. If for any reason BQ > on one node detects, the other node stops updating it=E2=80=99s stamps, i= t > performs failover procedure. It=E2=80=99s quite a questionable, rude way,= I > can agree, and that=E2=80=99s why I always write a warning to use the Bea= ST > for testing only purposes.=20 >=20 > Best regards, > Mike >=20 > > 24 =D0=B0=D0=BF=D1=80. 2018 =D0=B3., =D0=B2 9:09, Karli Sj=C3=B6berg <k= arli@inparadise.se> > > =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB(=D0=B0): > >=20 > > > On Mon, 2018-04-23 at 13:11 -0400, Mike Tancsa wrote: > > > > On 4/23/2018 12:59 PM, Mikhail Zakharov wrote: > > > >=20 > > > > Hello Mike, > > > >=20 > > > > Thank you for your interest to my paper. I appreciate it very > > > > much! > > > > Your error may be a consequence of the initial HA > > > > misconfiguration. > > > > What is in your /boot/loader.conf? Although the described > > > > config is > > > > quite simple, I can recheck the instruction in my paper in a > > > > couple > > > > of weeks only, unfortunately I=E2=80=99m on vacation right now. > >=20 > > [snip] > >=20 > > I read your articles on CTL HA, BQ and BeaST, and just wanted to > > say > > they are amazing, good job! > >=20 > > One thing I=C2=B4m wondering about though is if you can claim HA with > > just > > two nodes, usually you need at least three, where the third is a > > tie- > > breaker. Otherwise with your current setup, both systems may loose > > contact with each other while both still being powered on, leading > > to > > potential split brain situations. What are your thoughts about > > that? > >=20 > > /K >=20 >=20 --=-x4uETt1Aeoun59RYDAqh Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEcBAABCAAGBQJa3w5FAAoJEBpo164N2cuRxRYH/A77xGcrCRgnaB0dvNAgifU2 kBkrQsFSkOpN5SP+JGsdWo4chYrNL7xdaDUy4VNCa1joElP8bgC+PIeUhgqdlOHd F2iolSy7IpXoC7R77kAxqXo4B0zny6rxLhFjwf5gWWAlkiXhswlqZPioPNGScNKc mwpfLzb2m4L9b0n8qwNy2aKb1yDMGP19cCILgPpTVL/yLoiLMI9TloPvh2q+gHP1 wzLI3rKFy6apGLERbAKEgQTVOHPQPbFAmVXlSigsWmOLDfvswwT9UlP4lszhf0sI 7/TFEsjtFAi987W32FecIhauE1+Dx3kNKuNcUX5HMYTsuRbU8iHe/rbWPyayM+8= =wDyl -----END PGP SIGNATURE----- --=-x4uETt1Aeoun59RYDAqh--
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