[Gluster-users] about tail command

[Anuradha Talur]

----- Original Message -----
> From: "songxin" <songxin_1980 at 126.com>
> To: "Anuradha Talur" <atalur at redhat.com>
> Cc: "gluster-user" <gluster-users at gluster.org>
> Sent: Wednesday, March 2, 2016 4:09:01 PM
> Subject: Re:Re: [Gluster-users] about tail command
> 
> 
> 
> Thank you for your reply.I have two more questions as below
> 
> 
> 1. the command "gluster v replace-brick " is async or sync?  The replace is
> complete when the command quit ?
It is a sync command, replacing the brick finishes as the command returns.

In one of the earlier mails I gave incomplete command for replace brick, sorry about that.
The only replace-brick operation allowed from glusterfs 3.7.9 onwards is
'gluster v replace-brick <volname> <hostname:src_brick> <hostname:dst_brick> commit force'.
> 2.I run "tail -n 0" on mount point.Does it trigger the heal?
> 
> 
> Thanks,
> Xin
> 
> 
> 
> 
> 
> 
> 
> At 2016-03-02 15:22:35, "Anuradha Talur" <atalur at redhat.com> wrote:
> >
> >
> >----- Original Message -----
> >> From: "songxin" <songxin_1980 at 126.com>
> >> To: "gluster-user" <gluster-users at gluster.org>
> >> Sent: Tuesday, March 1, 2016 7:19:23 PM
> >> Subject: [Gluster-users] about tail command
> >> 
> >> Hi,
> >> 
> >> recondition:
> >> A node:128.224.95.140
> >> B node:128.224.162.255
> >> 
> >> brick on A node:/data/brick/gv0
> >> brick on B node:/data/brick/gv0
> >> 
> >> 
> >> reproduce steps:
> >> 1.gluster peer probe 128.224.162.255 (on A node)
> >> 2. gluster volume create gv0 replica 2 128.224.95.140:/data/brick/gv0
> >> 128.224.162.255:/data/brick/gv0 force (on A node)
> >> 3.gluster volume start gv0 (on A node)
> >> 4. mount -t glusterfs 128.224.95.140:/gv0 gluster (on A node)
> >> 5.create some files (a,b,c) in dir gluster (on A node)
> >> 6.shutdown the B node
> >> 7.change the files (a,b,c) in dir gluster (on A node)
> >> 8.reboot B node
> >> 9.start glusterd on B node but glusterfsd is offline (on B node)
> >> 10. gluster volume remove-brick gv0 replica 1
> >> 128.224.162.255:/data/brick/gv0
> >> force (on A node)
> >> 11. gluster volume add-brick gv0 replica 2 128.224.162.255:/data/brick/gv0
> >> force (on A node)
> >> 
> >> Now the files are not same between two brick
> >> 
> >> 12." gluster volume heal gv0 info " show entry num is 0 (on A node)
> >> 
> >> Now What I should do if I want to sync file(a,b,c) on two brick?
> >> 
> >Currently, once you add a brick to a cluster, files won't sync
> >automatically.
> >Patch has been sent to handle this requirement. Auto-heal will be available
> >soon.
> >
> >You could kill the newly added brick and perform the following operations
> >from mount
> >for the sync to start :
> >1) create a directory <dirname>
> >2) setfattr -n "user.dirname" -v "value" <dirname>
> >3) delete the directory <dirname>
> >
> >Once these steps are done, start the killed brick. self-heal-daemon will
> >heal the files.
> >
> >But, for the case you have mentioned, why are you removing brick and using
> >add-brick again?
> >Is it because you don't want to change the brick-path?
> >
> >You could use "replace-brick" command.
> >gluster v replace-brick <volname> <hostname:old-brick-path>
> ><hostname:new-brick-path>
> >Note that source and destination should be different for this command to
> >work.
> >
> >> I know the "heal full" can work , but I think the command take too long
> >> time.
> >> 
> >> So I run "tail -n 1 file" to all file on A node, but some files are sync
> >> but
> >> some files are not.
> >> 
> >> My question is below:
> >> 1.Why the tail can't sync all files?
> >Did you run the tail command on mount point or from the backend (bricks)?
> >If you run from bricks, sync won't happen. Was client-side healing on?
> >To check if they were on or off, run `gluster v get volname all | grep
> >self-heal`, cluster.metadata-self-heal, cluster.data-self-heal,
> >cluster.entry-self-heal should be on.
> >
> >> 2.Can the command "tail -n 1 filename" trigger selfheal, just like "ls -l
> >> filename"?
> >> 
> >> Thanks,
> >> Xin
> >> 
> >> 
> >> 
> >> 
> >> 
> >> 
> >> 
> >> 
> >> 
> >> 
> >> 
> >> _______________________________________________
> >> Gluster-users mailing list
> >> Gluster-users at gluster.org
> >> http://www.gluster.org/mailman/listinfo/gluster-users
> >
> >--
> >Thanks,
> >Anuradha.
> 

-- 
Thanks,
Anuradha.