Re: [ceph-users] When all Mons are down, does existing RBD volume continue to work

[Gregory Farnum]

I think things would keep running, but I'm really not sure. This is just
not a realistic concern as there are lots of little housekeeping things
that can be deferred for a little while but eventually will stop forward
progress if you can't talk to the monitors to persist cluster state updates.

On Tue, Mar 6, 2018 at 9:50 AM Mayank Kumar  wrote:

> Thanks Gregory. This is basically just trying to understand the behavior
> of the system in a failure scenario . Ideally we would track and fix mons
> going down promptly .
>
> In an ideal world where nothing else fails and there cephx is not in use
> but mons are down , what happens if the osd pings to mons time-out ? Would
> that start resulting in I/O failures ?
>
>
> On Mon, Mar 5, 2018 at 9:44 PM Gregory Farnum  wrote:
>
>> On Sun, Mar 4, 2018 at 12:02 AM Mayank Kumar  wrote:
>>
>>> Ceph Users,
>>>
>>> My question is if all mons are down(i know its a terrible situation to
>>> be), does an existing rbd volume which is mapped to a host and being
>>> used(read/written to) continues to work?
>>>
>>> I understand that it wont get notifications about osdmap, etc, but
>>> assuming nothing fails, does the read/write ios on the exsiting rbd volume
>>> continue to work or that would start failing ?
>>>
>>
>> Clients will continue to function if there are transient monitor issues,
>> but you can't rely on them continuing in a long-term failure scenario.
>> Eventually *something* will hit a timeout, whether that's an OSD on its
>> pings, or some kind of key rotation for cephx, or
>>
>
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Re: [ceph-users] When all Mons are down, does existing RBD volume continue to work

[Mayank Kumar]

Thanks Gregory. This is basically just trying to understand the behavior of
the system in a failure scenario . Ideally we would track and fix mons
going down promptly .

In an ideal world where nothing else fails and there cephx is not in use
but mons are down , what happens if the osd pings to mons time-out ? Would
that start resulting in I/O failures ?


On Mon, Mar 5, 2018 at 9:44 PM Gregory Farnum  wrote:

> On Sun, Mar 4, 2018 at 12:02 AM Mayank Kumar  wrote:
>
>> Ceph Users,
>>
>> My question is if all mons are down(i know its a terrible situation to
>> be), does an existing rbd volume which is mapped to a host and being
>> used(read/written to) continues to work?
>>
>> I understand that it wont get notifications about osdmap, etc, but
>> assuming nothing fails, does the read/write ios on the exsiting rbd volume
>> continue to work or that would start failing ?
>>
>
> Clients will continue to function if there are transient monitor issues,
> but you can't rely on them continuing in a long-term failure scenario.
> Eventually *something* will hit a timeout, whether that's an OSD on its
> pings, or some kind of key rotation for cephx, or
>
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Re: [ceph-users] When all Mons are down, does existing RBD volume continue to work

[Gregory Farnum]

On Sun, Mar 4, 2018 at 12:02 AM Mayank Kumar  wrote:

> Ceph Users,
>
> My question is if all mons are down(i know its a terrible situation to
> be), does an existing rbd volume which is mapped to a host and being
> used(read/written to) continues to work?
>
> I understand that it wont get notifications about osdmap, etc, but
> assuming nothing fails, does the read/write ios on the exsiting rbd volume
> continue to work or that would start failing ?
>

Clients will continue to function if there are transient monitor issues,
but you can't rely on them continuing in a long-term failure scenario.
Eventually *something* will hit a timeout, whether that's an OSD on its
pings, or some kind of key rotation for cephx, or
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[ceph-users] When all Mons are down, does existing RBD volume continue to work

[Mayank Kumar]

Ceph Users,

My question is if all mons are down(i know its a terrible situation to be),
does an existing rbd volume which is mapped to a host and being
used(read/written to) continues to work?

I understand that it wont get notifications about osdmap, etc, but assuming
nothing fails, does the read/write ios on the exsiting rbd volume continue
to work or that would start failing ?

-Mayank
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