[Gluster-Maintainers] [Gluster-devel] [Gluster-users] Don't allow data loss via add-brick (was Re: Add single server)

[Raghavendra Talur]

On Tue, May 2, 2017 at 8:46 PM, Nithya Balachandran <nbalacha at redhat.com> wrote:
>
>
> On 2 May 2017 at 16:59, Shyam <srangana at redhat.com> wrote:
>>
>> Talur,
>>
>> Please wait for this fix before releasing 3.10.2.
>>
>> We will take in the change to either prevent add-brick in
>> sharded+distrbuted volumes, or throw a warning and force the use of --force
>> to execute this.

Agreed, I have filed bug and marked as blocker for 3.10.2.
https://bugzilla.redhat.com/show_bug.cgi?id=1447608


>>
> IIUC, the problem is less the add brick operation and more the
> rebalance/fix-layout. It is those that need to be prevented (as someone
> could trigger those without an add-brick).

Yes, that problem seems to be with fix-layout/rebalance and not add-brick.
However, depending on how users have arranged their dir structure, a
add-brick without a fix-layout might be useless for them.

I also had a look at the code to see if I can do the cli/glusterd
change myself. However, sharding is enabled just as a xlator and not
added to glusterd_volinfo_t.
If someone from dht team could work with glusterd team here it would
fix the issue faster.

Action item on Nithya/Atin to assign bug 1447608 to someone. I will
wait for the fix for 3.10.2.

Thanks,
Raghavendra Talur

>
> Nithya
>>
>> Let's get a bug going, and not wait for someone to report it in bugzilla,
>> and also mark it as blocking 3.10.2 release tracker bug.
>>
>> Thanks,
>> Shyam
>>
>> On 05/02/2017 06:20 AM, Pranith Kumar Karampuri wrote:
>>>
>>>
>>>
>>> On Tue, May 2, 2017 at 9:16 AM, Pranith Kumar Karampuri
>>> <pkarampu at redhat.com <mailto:pkarampu at redhat.com>> wrote:
>>>
>>>     Yeah it is a good idea. I asked him to raise a bug and we can move
>>>     forward with it.
>>>
>>>
>>> +Raghavendra/Nitya who can help with the fix.
>>>
>>>
>>>
>>>     On Mon, May 1, 2017 at 9:07 PM, Joe Julian <joe at julianfamily.org
>>>     <mailto:joe at julianfamily.org>> wrote:
>>>
>>>
>>>         On 04/30/2017 01:13 AM, lemonnierk at ulrar.net
>>>         <mailto:lemonnierk at ulrar.net> wrote:
>>>
>>>                 So I was a little but luck. If I has all the hardware
>>>                 part, probably i
>>>                 would be firesd after causing data loss by using a
>>>                 software marked as stable
>>>
>>>             Yes, we lost our data last year to this bug, and it wasn't a
>>>             test cluster.
>>>             We still hear from it from our clients to this day.
>>>
>>>                 Is known that this feature is causing data loss and
>>>                 there is no evidence or
>>>                 no warning in official docs.
>>>
>>>             I was (I believe) the first one to run into the bug, it
>>>             happens and I knew it
>>>             was a risk when installing gluster.
>>>             But since then I didn't see any warnings anywhere except
>>>             here, I agree
>>>             with you that it should be mentionned in big bold letters on
>>>             the site.
>>>
>>>             Might even be worth adding a warning directly on the cli
>>>             when trying to
>>>             add bricks if sharding is enabled, to make sure no-one will
>>>             destroy a
>>>             whole cluster for a known bug.
>>>
>>>
>>>         I absolutely agree - or, just disable the ability to add-brick
>>>         with sharding enabled. Losing data should never be allowed.
>>>         _______________________________________________
>>>         Gluster-devel mailing list
>>>         Gluster-devel at gluster.org <mailto:Gluster-devel at gluster.org>
>>>         http://lists.gluster.org/mailman/listinfo/gluster-devel
>>>         <http://lists.gluster.org/mailman/listinfo/gluster-devel>
>>>
>>>
>>>
>>>
>>>     --
>>>     Pranith
>>>
>>>     _______________________________________________
>>>     Gluster-users mailing list
>>>     Gluster-users at gluster.org <mailto:Gluster-users at gluster.org>
>>>     http://lists.gluster.org/mailman/listinfo/gluster-users
>>>     <http://lists.gluster.org/mailman/listinfo/gluster-users>
>>>
>>>
>>>
>>>
>>> --
>>> Pranith
>>>
>>>
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