This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --LpidP5sDUwnqXvKTBqwmoV4WNgVOc3LVR Content-Type: multipart/mixed; boundary="EuwhS6IvMgri3Uvk0TBflcE1NlHpw3QJU"; protected-headers="v1" From: Kai Wagner <kwagner@suse.com> To: users@ovirt.org Message-ID: <a587b36a-adbd-8f7b-02cf-17c934347ae2@suse.com> Subject: Re: [ovirt-users] Advise needed: building cheap HA oVirt cluster with just 2 physical servers References: <CAAq+Rfab8fvhNV+uP2hEceJywaezEqyRSDwdBx60333SMR7k4A@mail.gmail.com> <15f80d35370.2768.ffe2d6cdf294efc1bb86526523af9945@kafit.se> <0711091c-66a5-7aa5-0241-3ceba2ba1240@arsys.es> <15f80f308a0.2768.ffe2d6cdf294efc1bb86526523af9945@kafit.se> In-Reply-To: <15f80f308a0.2768.ffe2d6cdf294efc1bb86526523af9945@kafit.se> --EuwhS6IvMgri3Uvk0TBflcE1NlHpw3QJU Content-Type: multipart/alternative; boundary="------------2D81AC2A3E3425E12F595D94" Content-Language: en-US This is a multi-part message in MIME format. --------------2D81AC2A3E3425E12F595D94 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Nevertheless you could end up with a split brain situation because you've no quorum. So it doesn't matter which kind of cluster you want to build, but you'll need a third node as a tiebreaker. I know that a 2 node cluster with drbd would work, but not in all cases, so do yourself a favor and get a third node. On 03.11.2017 09:15, Johan Bernhardsson wrote:
On drbd you have one master and use iscsi to share the storage. If the master fails it will fail over to the other.
You have one up that will act as the iscsi storage and jump between the hosts.
If you run drbd master master ... Then you might get split brain and that is not fun :)
On November 3, 2017 09:04:49 Eduardo Mayoral <emayoral@arsys.es> wrote:=
Just genuinely curious, how do you avoid split-brain situations with a 2-node setup (be it drbd, gluster or anything else)?
Eduardo Mayoral Jimeno (emayoral@arsys.es) Administrador de sistemas. Departamento de Plataformas. Arsys internet=
=2E
+34 941 620 145 ext. 5153 On 03/11/17 08:40, Johan Bernhardsson wrote:
Check on drbd. I have used that to build a cluster for two servers. It need some more work than a three node gluster conf but works well.=
I even think they have a white paper on how to do it for virtualizati=
on.
/Johan
On November 3, 2017 08:11:04 Artem Tambovskiy <artem.tambovskiy@gmail.com> wrote:
Looking for a design advise on oVirt provisioning. I'm running a PoC lab on single bare-metal host (suddenly it was setup with just Local Storage domain) and=C2=A0 no I'd like to rebuild the setup by making a cluster of 2 physical servers, no external storage array available. That are the options here? is there any options to build cheap HA cluster with just 2 servers?=C2=A0
Thanks in advance!
Artem _______________________________________________ Users mailing list Users@ovirt.org <mailto:Users%40ovirt.org> http://lists.ovirt.org/mailman/listinfo/users
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
--=20 SUSE Linux GmbH, GF: Felix Imend=C3=B6rffer, Jane Smithard, Graham Norton= , HRB 21284 (AG N=C3=BCrnberg) --------------2D81AC2A3E3425E12F595D94 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable <html> <head> <meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dutf= -8"> </head> <body text=3D"#000000" bgcolor=3D"#FFFFFF"> <p>Nevertheless you could end up with a split brain situation because you've no quorum.</p> <p>So it doesn't matter which kind of cluster you want to build, but you'll need a third node as a tiebreaker.</p> <p>I know that a 2 node cluster with drbd would work, but not in all cases, so do yourself a favor and get a third node. <br> </p> <br> <div class=3D"moz-cite-prefix">On 03.11.2017 09:15, Johan Bernhardsso= n wrote:<br> </div> <blockquote type=3D"cite" cite=3D"mid:15f80f308a0.2768.ffe2d6cdf294efc1bb86526523af9945@kafit= =2Ese"> <div style=3D"color: black;"> <div style=3D"color: black;"> <p style=3D"margin: 0 0 1em 0; color: black;">On drbd you have one master and use iscsi to share the storage. If the master fails it will fail over to the other.</p> <p style=3D"margin: 0 0 1em 0; color: black;">You have one up that will act as the iscsi storage and jump between the hosts.</p> <p style=3D"margin: 0 0 1em 0; color: black;">If you run drbd master master ... Then you might get split brain and that is not fun :)</p>= </div> <div style=3D"color: black;"> <p style=3D"color: black; font-size: 10pt; font-family: Arial, sans-serif; margin: 10pt 0;">On November 3, 2017 09:04:49 Eduardo Mayoral <a class=3D"moz-txt-link-rfc2396E" href=3D"mailto:emayoral@ar= sys.es"><emayoral@arsys.es></a> wrote:</p> <blockquote type=3D"cite" class=3D"gmail_quote" style=3D"margin= : 0 0 0 0.75ex; border-left: 1px solid #808080; padding-left: 0.75ex;"> <p>Just genuinely curious, how do you avoid split-brain situations with a 2-node setup (be it drbd, gluster or anything else)?<br> </p> <pre class=3D"moz-signature" cols=3D"72">Eduardo Mayoral Jime= no (<a class=3D"moz-txt-link-abbreviated" href=3D"mailto:emayoral@arsys.e= s" moz-do-not-send=3D"true">emayoral@arsys.es</a>) Administrador de sistemas. Departamento de Plataformas. Arsys internet. +34 941 620 145 ext. 5153</pre> <div class=3D"moz-cite-prefix">On 03/11/17 08:40, Johan Bernhardsson wrote:<br> </div> <blockquote type=3D"cite" cite=3D"mid:15f80d35370.2768.ffe2d6cdf294efc1bb86526523af99= 45@kafit.se"> <meta http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dutf-8"> <div style=3D"color: black;"> <div style=3D"color: black;"> <p style=3D"margin: 0 0 1em 0; color: black;">Check on drbd. I have used that to build a cluster for two servers. It need some more work than a three node gluster conf but works well.</p> <p style=3D"margin: 0 0 1em 0; color: black;">I even think they have a white paper on how to do it for virtualization.</p> <p style=3D"margin: 0 0 1em 0; color: black;">/Johan</p=
</div> <div style=3D"color: black;"> <p style=3D"color: black; font-size: 10pt; font-family:= Arial, sans-serif; margin: 10pt 0;">On November 3, 2017 08:11:04 Artem Tambovskiy <a class=3D"moz-txt-link-rfc2396E" href=3D"mailto:artem.tambovskiy@gmail.com" moz-do-not-send=3D"true"><artem.tambovskiy@gmail= =2Ecom></a> wrote:</p> <blockquote type=3D"cite" class=3D"gmail_quote" style=3D"margin: 0 0 0 0.75ex; border-left: 1px solid= #808080; padding-left: 0.75ex;"> <div dir=3D"ltr"> <div>Looking for a design advise on oVirt provisioning. I'm running a PoC lab on single bare-metal host (suddenly it was setup with just Local Storage domain) and=C2=A0</div> <div>no I'd like to rebuild the setup by making a cluster of 2 physical servers, no external storage array available. That are the options here? is there any options to build cheap HA cluster with just 2 servers?=C2=A0</div> <div><br> </div> <div>Thanks in advance!</div> <div><br> </div> <div>Artem</div> </div> _______________________________________________<br> Users mailing list<br> <a class=3D"aqm-autolink aqm-autowrap" href=3D"mailto:Users%40ovirt.org" moz-do-not-send=3D"true">Users@ovirt.org</a><br> <a class=3D"aqm-autolink aqm-autowrap" href=3D"http://lists.ovirt.org/mailman/listinfo/use= rs" moz-do-not-send=3D"true">http://lists.ovirt.org/mai= lman/listinfo/users</a><br> <br> </blockquote> </div> </div> <br> <fieldset class=3D"mimeAttachmentHeader"></fieldset> <br> <pre wrap=3D"">____________________________________________= ___ Users mailing list <a class=3D"moz-txt-link-abbreviated" href=3D"mailto:Users@ovirt.org" moz= -do-not-send=3D"true">Users@ovirt.org</a> <a class=3D"moz-txt-link-freetext" href=3D"http://lists.ovirt.org/mailman= /listinfo/users" moz-do-not-send=3D"true">http://lists.ovirt.org/mailman/= listinfo/users</a> </pre> </blockquote> <br> </blockquote> </div> </div> <br> <fieldset class=3D"mimeAttachmentHeader"></fieldset> <br> <pre wrap=3D"">_______________________________________________ Users mailing list <a class=3D"moz-txt-link-abbreviated" href=3D"mailto:Users@ovirt.org">Use= rs@ovirt.org</a> <a class=3D"moz-txt-link-freetext" href=3D"http://lists.ovirt.org/mailman= /listinfo/users">http://lists.ovirt.org/mailman/listinfo/users</a> </pre> </blockquote> <br> <pre class=3D"moz-signature" cols=3D"72">--=20 SUSE Linux GmbH, GF: Felix Imend=C3=B6rffer, Jane Smithard, Graham Norton= , HRB 21284 (AG N=C3=BCrnberg)</pre> </body> </html> --------------2D81AC2A3E3425E12F595D94-- --EuwhS6IvMgri3Uvk0TBflcE1NlHpw3QJU-- --LpidP5sDUwnqXvKTBqwmoV4WNgVOc3LVR Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJZ/DGZAAoJEB6MkVYW48Ruh90H/i/6pG6WJtfRBlwM5LaQ1AcK OvzOmoFaX+ZBjq1jUOjghspUO0UUX1FR4OuSoDXMIUk2p7EAhrUoBKSzpXNjw//2 gCLMMMGW3iNAKXsVvnHeNfm4xTMdM6uNtGGSaS6Z4w9gbvrX99HoPnQx3KdiL7Cl 3uEj3Yl5rp4clTy5MRIFFNTweei6KnWyssSkHgmaH+oeqnkTeIdkvYlfDVDkhXfo dl1/K0FoPMlnEccHzh2mdXEItBFr5FhPxWpFob/6dINci4dSiLy3mQ0h87aTy9+q DUOOM4efQ0wWr5+AOtmo2gPrBR5yNrnm3qMjjgB8gKytWmxKUcFjmNPXFd4ge/o= =oCXV -----END PGP SIGNATURE----- --LpidP5sDUwnqXvKTBqwmoV4WNgVOc3LVR--