Hi Neil, docs mention two live nodes of replica 3 blaming each other and refusing to do IO.
https://gluster.readthedocs.io/en/latest/Administrator%20Guide/Split%20brain%20and%20ways%20to%20deal%20with%20it/#1-replica-3-volume On Sep 7, 2017 17:52, "Alastair Neil" <ajneil.t...@gmail.com> wrote: > *shrug* I don't use arbiter for vm work loads just straight replica 3. > There are some gotchas with using an arbiter for VM workloads. If > quorum-type is auto and a brick that is not the arbiter drop out then if > the up brick is dirty as far as the arbiter is concerned i.e. the only good > copy is on the down brick you will get ENOTCONN and your VMs will halt on > IO. > > On 6 September 2017 at 16:06, <lemonni...@ulrar.net> wrote: > >> Mh, I never had to do that and I never had that problem. Is that an >> arbiter specific thing ? With replica 3 it just works. >> >> On Wed, Sep 06, 2017 at 03:59:14PM -0400, Alastair Neil wrote: >> > you need to set >> > >> > cluster.server-quorum-ratio 51% >> > >> > On 6 September 2017 at 10:12, Pavel Szalbot <pavel.szal...@gmail.com> >> wrote: >> > >> > > Hi all, >> > > >> > > I have promised to do some testing and I finally find some time and >> > > infrastructure. >> > > >> > > So I have 3 servers with Gluster 3.10.5 on CentOS 7. I created >> > > replicated volume with arbiter (2+1) and VM on KVM (via Openstack) >> > > with disk accessible through gfapi. Volume group is set to virt >> > > (gluster volume set gv_openstack_1 virt). VM runs current (all >> > > packages updated) Ubuntu Xenial. >> > > >> > > I set up following fio job: >> > > >> > > [job1] >> > > ioengine=libaio >> > > size=1g >> > > loops=16 >> > > bs=512k >> > > direct=1 >> > > filename=/tmp/fio.data2 >> > > >> > > When I run fio fio.job and reboot one of the data nodes, IO statistics >> > > reported by fio drop to 0KB/0KB and 0 IOPS. After a while, root >> > > filesystem gets remounted as read-only. >> > > >> > > If you care about infrastructure, setup details etc., do not hesitate >> to >> > > ask. >> > > >> > > Gluster info on volume: >> > > >> > > Volume Name: gv_openstack_1 >> > > Type: Replicate >> > > Volume ID: 2425ae63-3765-4b5e-915b-e132e0d3fff1 >> > > Status: Started >> > > Snapshot Count: 0 >> > > Number of Bricks: 1 x (2 + 1) = 3 >> > > Transport-type: tcp >> > > Bricks: >> > > Brick1: gfs-2.san:/export/gfs/gv_1 >> > > Brick2: gfs-3.san:/export/gfs/gv_1 >> > > Brick3: docker3.san:/export/gfs/gv_1 (arbiter) >> > > Options Reconfigured: >> > > nfs.disable: on >> > > transport.address-family: inet >> > > performance.quick-read: off >> > > performance.read-ahead: off >> > > performance.io-cache: off >> > > performance.stat-prefetch: off >> > > performance.low-prio-threads: 32 >> > > network.remote-dio: enable >> > > cluster.eager-lock: enable >> > > cluster.quorum-type: auto >> > > cluster.server-quorum-type: server >> > > cluster.data-self-heal-algorithm: full >> > > cluster.locking-scheme: granular >> > > cluster.shd-max-threads: 8 >> > > cluster.shd-wait-qlength: 10000 >> > > features.shard: on >> > > user.cifs: off >> > > >> > > Partial KVM XML dump: >> > > >> > > <disk type='network' device='disk'> >> > > <driver name='qemu' type='raw' cache='none'/> >> > > <source protocol='gluster' >> > > name='gv_openstack_1/volume-77ebfd13-6a92-4f38-b036-e9e55d752e1e'> >> > > <host name='10.0.1.201' port='24007'/> >> > > </source> >> > > <backingStore/> >> > > <target dev='vda' bus='virtio'/> >> > > <serial>77ebfd13-6a92-4f38-b036-e9e55d752e1e</serial> >> > > <alias name='virtio-disk0'/> >> > > <address type='pci' domain='0x0000' bus='0x00' slot='0x04' >> > > function='0x0'/> >> > > </disk> >> > > >> > > Networking is LACP on data nodes, stack of Juniper EX4550's (10Gbps >> > > SFP+), separate VLAN for Gluster traffic, SSD only on Gluster all >> > > nodes (including arbiter). >> > > >> > > I would really love to know what am I doing wrong, because this is my >> > > experience with Gluster for a long time a and a reason I would not >> > > recommend it as VM storage backend in production environment where you >> > > cannot start/stop VMs on your own (e.g. providing private clouds for >> > > customers). >> > > -ps >> > > >> > > >> > > On Sun, Sep 3, 2017 at 10:21 PM, Gionatan Danti <g.da...@assyoma.it> >> > > wrote: >> > > > Il 30-08-2017 17:07 Ivan Rossi ha scritto: >> > > >> >> > > >> There has ben a bug associated to sharding that led to VM >> corruption >> > > >> that has been around for a long time (difficult to reproduce I >> > > >> understood). I have not seen reports on that for some time after >> the >> > > >> last fix, so hopefully now VM hosting is stable. >> > > > >> > > > >> > > > Mmmm... this is precisely the kind of bug that scares me... data >> > > corruption >> > > > :| >> > > > Any more information on what causes it and how to resolve? Even if >> in >> > > newer >> > > > Gluster releases it is a solved bug, knowledge on how to treat it >> would >> > > be >> > > > valuable. >> > > > >> > > > >> > > > Thanks. >> > > > >> > > > -- >> > > > Danti Gionatan >> > > > Supporto Tecnico >> > > > Assyoma S.r.l. - www.assyoma.it >> > > > email: g.da...@assyoma.it - i...@assyoma.it >> > > > GPG public key ID: FF5F32A8 >> > > > _______________________________________________ >> > > > Gluster-users mailing list >> > > > Gluster-users@gluster.org >> > > > http://lists.gluster.org/mailman/listinfo/gluster-users >> > > _______________________________________________ >> > > Gluster-users mailing list >> > > Gluster-users@gluster.org >> > > http://lists.gluster.org/mailman/listinfo/gluster-users >> > > >> >> > _______________________________________________ >> > Gluster-users mailing list >> > Gluster-users@gluster.org >> > http://lists.gluster.org/mailman/listinfo/gluster-users >> >> >> _______________________________________________ >> Gluster-users mailing list >> Gluster-users@gluster.org >> http://lists.gluster.org/mailman/listinfo/gluster-users >> > > > _______________________________________________ > Gluster-users mailing list > Gluster-users@gluster.org > http://lists.gluster.org/mailman/listinfo/gluster-users >
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