Re: [Gluster-users] Replica 3 - how to replace failed node (peer)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On Thu, Apr 11, 2019 at 12:43 PM Martin Toth <snowmailer@xxxxxxxxx> wrote:
Hi Karthik,

more over, I would like to ask if there are some recommended settings/parameters for SHD in order to achieve good or fair I/O while volume will be healed when I will replace Brick (this should trigger healing process). 
If I understand you concern correctly, you need to get fair I/O performance for clients while healing takes place as part of  the replace brick operation. For this you can turn off the "data-self-heal" and "metadata-self-heal" options until the heal completes on the new brick.
Turning off client side healing doesn't compromise data integrity and consistency. During the read request from client, pending xattr is evaluated for replica copies and read is only served from correct copy. During writes, IO will continue on both the replicas, SHD will take care of healing files.
After replacing the brick, we strongly recommend you to consider upgrading your gluster to one of the maintained versions. We have many stability related fixes there, which can handle some critical issues and corner cases which you could hit during these kind of scenarios.

Regards,
Karthik
I had some problems in past when healing was triggered, VM disks became unresponsive because healing took most of I/O. My volume containing only big files with VM disks.

Thanks for suggestions.
BR, 
Martin

On 10 Apr 2019, at 12:38, Martin Toth <snowmailer@xxxxxxxxx> wrote:

Thanks, this looks ok to me, I will reset brick because I don't have any data anymore on failed node so I can use same path / brick name.

Is reseting brick dangerous command? Should I be worried about some possible failure that will impact remaining two nodes? I am running really old 3.7.6 but stable version.

Thanks,
BR!

Martin
 

On 10 Apr 2019, at 12:20, Karthik Subrahmanya <ksubrahm@xxxxxxxxxx> wrote:

Hi Martin,

After you add the new disks and creating raid array, you can run the following command to replace the old brick with new one:

- If you are going to use a different name to the new brick you can run
gluster volume replace-brick <volname> <old-brick> <new-brick> commit force

- If you are planning to use the same name for the new brick as well then you can use
gluster volume reset-brick <volname> <old-brick> <new-brick> commit force
Here old-brick & new-brick's hostname &  path should be same.

After replacing the brick, make sure the brick comes online using volume status.
Heal should automatically start, you can check the heal status to see all the files gets replicated to the newly added brick. If it does not start automatically, you can manually start that by running gluster volume heal <volname>.

HTH,
Karthik

On Wed, Apr 10, 2019 at 3:13 PM Martin Toth <snowmailer@xxxxxxxxx> wrote:
Hi all,

I am running replica 3 gluster with 3 bricks. One of my servers failed - all disks are showing errors and raid is in fault state.

Type: Replicate
Volume ID: 41d5c283-3a74-4af8-a55d-924447bfa59a
Status: Started
Number of Bricks: 1 x 3 = 3
Transport-type: tcp
Bricks:
Brick1: node1.san:/tank/gluster/gv0imagestore/brick1
Brick2: node2.san:/tank/gluster/gv0imagestore/brick1 <— this brick is down
Brick3: node3.san:/tank/gluster/gv0imagestore/brick1

So one of my bricks is totally failed (node2). It went down and all data are lost (failed raid on node2). Now I am running only two bricks on 2 servers out from 3.
This is really critical problem for us, we can lost all data. I want to add new disks to node2, create new raid array on them and try to replace failed brick on this node.

What is the procedure of replacing Brick2 on node2, can someone advice? I can’t find anything relevant in documentation.

Thanks in advance,
Martin
_______________________________________________
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
https://lists.gluster.org/mailman/listinfo/gluster-users


_______________________________________________
Gluster-devel mailing list
Gluster-devel@xxxxxxxxxxx
https://lists.gluster.org/mailman/listinfo/gluster-devel

[Index of Archives]     [Gluster Users]     [Ceph Users]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux