start ... force is, indeed, a dangerous command. If your brick failed to mount, gluster will not find the volume-id extended attribute and will recognize that the path is not a brick and will not start the brick daemon preventing filling up your root partition with replicated files. When you replace a brick, the new filesystem will not have that attribute so "force" is required to override that safety check. On August 11, 2016 6:43:54 AM PDT, Gandalf Corvotempesta <gandalf.corvotempesta@xxxxxxxxx> wrote: >2016-08-11 13:08 GMT+02:00 Lindsay Mathieson ><lindsay.mathieson@xxxxxxxxx>: >> Also "gluster volume status" lists the pid's of all the bricks >processes. > >Ok, let's break everything., just to try. > >This is a working cluster. I have 3 server with 1 brick each, in >replica 3, thus, all files are replicated on all hosts. > ># gluster volume info > >Volume Name: gv0 >Type: Replicate >Volume ID: 2a36dc0f-1d9b-469c-82de-9d8d98321b83 >Status: Started >Number of Bricks: 1 x 3 = 3 >Transport-type: tcp >Bricks: >Brick1: 1.2.3.112:/export/sdb1/brick >Brick2: 1.2.3.113:/export/sdb1/brick >Brick3: 1.2.3.114:/export/sdb1/brick >Options Reconfigured: >nfs.disable: on >performance.readdir-ahead: on >transport.address-family: inet >features.shard: off >features.shard-block-size: 10MB >performance.write-behind-window-size: 1GB >performance.cache-size: 1GB > > >I did this on a client: > ># echo 'hello world' > hello ># md5sum hello >6f5902ac237024bdd0c176cb93063dc4 hello > >Obviously, on node 1.2.3.112 I have it: > ># cat /export/sdb1/brick/hello >hello world ># md5sum /export/sdb1/brick/hello >6f5902ac237024bdd0c176cb93063dc4 /export/sdb1/brick/hello > > > >Let's break everything, this is funny. >I take the brick pid from here: ># gluster volume status | grep 112 >Brick 1.2.3.112:/export/sdb1/brick 49152 0 Y >14315 > > ># kill -9 14315 > ># gluster volume status | grep 112 >Brick 1.2.3.112:/export/sdb1/brick N/A N/A N >N/A > >this should be like a dregraded cluster, right ? > >Now I add a new file from the client: >echo "hello world, i'm degraded" > degraded > >Obviously, this file is not replicated on node 1.2.3.112 > ># gluster volume heal gv0 info >Brick 1.2.3.112:/export/sdb1/brick >Status: Transport endpoint is not connected >Number of entries: - > >Brick 1.2.3.113:/export/sdb1/brick >/degraded >/ >Status: Connected >Number of entries: 2 > >Brick 1.2.3.114:/export/sdb1/brick >/degraded >/ >Status: Connected >Number of entries: 2 > > > >This means that "/" dir and "/degraded" file should be healed from >.113 and .114 ? > >Let's format the disk on .112 ># umount /dev/sdb1 ># mkfs.xfs /dev/sdb1 -f >meta-data=/dev/sdb1 isize=256 agcount=4, >agsize=122094597 blks > = sectsz=4096 attr=2, projid32bit=1 > = crc=0 finobt=0 >data = bsize=4096 blocks=488378385, >imaxpct=5 > = sunit=0 swidth=0 blks >naming =version 2 bsize=4096 ascii-ci=0 ftype=0 >log =internal log bsize=4096 blocks=238466, version=2 > = sectsz=4096 sunit=1 blks, lazy-count=1 >realtime =none extsz=4096 blocks=0, rtextents=0 > > >Now I mount it again on the old place: > ># mount /dev/sdb1 /export/sdb1 > >it's empty: ># ls /export/sdb1/ -la >total 4 >drwxr-xr-x 2 root root 6 Aug 11 15:37 . >drwxr-xr-x 3 root root 4096 Jul 5 17:03 .. > >I create the "brick" directory used by gluster: > ># mkdir /export/sdb1/brick > >Now I run the volume start force: > ># gluster volume start gv0 force >volume start: gv0: success > >But brick process is still down: > ># gluster volume status | grep 112 >Brick 1.2.3.112:/export/sdb1/brick N/A N/A N >N/A > > > >And now ? > >What I really don't like is the use of "force" in "gluster volume >start" >Usually (in all software) force is used when "bad things" are needed. >In this case, the volume start is mandatory, thus why I have to use >the force? >If the volume is already started, gluster should be smart enough to >start only the missing processes, without force, or, better, another >command should be created, something like: "gluster bricks start" >using the force means running dangerous operation, not a common >administrative task. >_______________________________________________ >Gluster-users mailing list >Gluster-users@xxxxxxxxxxx >http://www.gluster.org/mailman/listinfo/gluster-users -- Sent from my Android device with K-9 Mail. Please excuse my brevity. _______________________________________________ Gluster-users mailing list Gluster-users@xxxxxxxxxxx http://www.gluster.org/mailman/listinfo/gluster-users
