Mailing List Archive

4 node cluster - only two nodes coming up
Hi all,

We're in the middle of hell, where our 4-node FAS8060 cluster was
shutdown cleanly for a move, but only one pair made it onto the truck
to the new DC. Luckily I have all the volumes snapmirrored between
the two pairs of nodes and their aggregates.

But now I need to bring up the pair that made the trip, figure out
which mirrors are source and which are destination on this pair, and
then break the destination ones so I can promote them to read-write.

This is not something I've practiced, and I wonder that if I have
volume foo, mounted on /foo, and it's snapmirror is volume foo_sm,
when I do the break, will it automatically mount to /foo? I guess
I'll find out later tonight, and I can just unmount and remount.

I think this is all good with just a simple 'snapmirror break ...' but
then when we get the chance to rejoin the other two nodes into the
cluster down the line, I would asusme I just have to (maybe) wipe the
old nodes and rejoin them one at a time. Mostly because by that point
I can't have the original source volumes come up and cause us to lose
all the writes that have happened on the now writeable destination
volumes.

And of course there's the matter of getting epsilon back up and
working on the two node cluster when I reboot it. Along with all the
LIFs, etc. Not going to be a fun time. Not at all...

And of course we're out of support with Netapp. Sigh...

And who knows if the pair that came down won't lose some disks and end
up losing one or more aggregates as well. Stressful times for sure.

So I'm just venting here, but any suggestions or tricks would be
helpful.

And of course I'm not sure if the cluster switches made it down here
yet.

Never put your DC on the second floor if there isn't a second freight
elevator. Or elevator in general. Sigh...

John
_______________________________________________
Toasters mailing list
Toasters@teaparty.net
https://www.teaparty.net/mailman/listinfo/toasters
Re: 4 node cluster - only two nodes coming up [ In reply to ]
John,

If it were me, I would take it one step at a time and first get the systems physically in place, cabled up and clusters switches up and running and once you can login on console or SSH then start looking at the aggregates, LIF's, cluster epsilon/quorum and which volumes are source, etc. Keep me posted if you hit any major roadblocks and I can try to help out.

Thank you,
Tim

________________________________
From: Toasters <toasters-bounces@teaparty.net> on behalf of John Stoffel <john@stoffel.org>
Sent: Saturday, May 15, 2021 6:47 PM
To: <Toasters@teaparty.net> <Toasters@teaparty.net>
Subject: 4 node cluster - only two nodes coming up



Hi all,

We're in the middle of hell, where our 4-node FAS8060 cluster was
shutdown cleanly for a move, but only one pair made it onto the truck
to the new DC. Luckily I have all the volumes snapmirrored between
the two pairs of nodes and their aggregates.

But now I need to bring up the pair that made the trip, figure out
which mirrors are source and which are destination on this pair, and
then break the destination ones so I can promote them to read-write.

This is not something I've practiced, and I wonder that if I have
volume foo, mounted on /foo, and it's snapmirror is volume foo_sm,
when I do the break, will it automatically mount to /foo? I guess
I'll find out later tonight, and I can just unmount and remount.

I think this is all good with just a simple 'snapmirror break ...' but
then when we get the chance to rejoin the other two nodes into the
cluster down the line, I would asusme I just have to (maybe) wipe the
old nodes and rejoin them one at a time. Mostly because by that point
I can't have the original source volumes come up and cause us to lose
all the writes that have happened on the now writeable destination
volumes.

And of course there's the matter of getting epsilon back up and
working on the two node cluster when I reboot it. Along with all the
LIFs, etc. Not going to be a fun time. Not at all...

And of course we're out of support with Netapp. Sigh...

And who knows if the pair that came down won't lose some disks and end
up losing one or more aggregates as well. Stressful times for sure.

So I'm just venting here, but any suggestions or tricks would be
helpful.

And of course I'm not sure if the cluster switches made it down here
yet.

Never put your DC on the second floor if there isn't a second freight
elevator. Or elevator in general. Sigh...

John
_______________________________________________
Toasters mailing list
Toasters@teaparty.net
https://www.teaparty.net/mailman/listinfo/toasters
Re: 4 node cluster - only two nodes coming up [ In reply to ]
You can only bring up two nodes if one of them has epsilon. Otherwise no configuration changes are possible and that includes breaking snap mirror.

If those two nodes do have epsilon, it is just normal procedure to failover LIF. After snap mirror break destinations volumes are not renamed - they remain exactly as they are. Nothing special needs to be done when two remaining nodes arrive - they just join cluster normally.

If these two nodes do not have epsilon, your best bet is to wait for the remaining cluster nodes to arrive. I am not aware of possibility to force epsilon in this case. May be it exists, but you certainly need support case to obtain it and any follow up step.

???????? Outlook ??? iOS<https://aka.ms/o0ukef>
________________________________
??: ???????????? Toasters <toasters-bounces@teaparty.net> ?? ????? ???????????? John Stoffel <john@stoffel.org>
??????????: ???????????, ??? 16, 2021 04:54
????: <Toasters@teaparty.net>
????: 4 node cluster - only two nodes coming up



Hi all,

We're in the middle of hell, where our 4-node FAS8060 cluster was
shutdown cleanly for a move, but only one pair made it onto the truck
to the new DC. Luckily I have all the volumes snapmirrored between
the two pairs of nodes and their aggregates.

But now I need to bring up the pair that made the trip, figure out
which mirrors are source and which are destination on this pair, and
then break the destination ones so I can promote them to read-write.

This is not something I've practiced, and I wonder that if I have
volume foo, mounted on /foo, and it's snapmirror is volume foo_sm,
when I do the break, will it automatically mount to /foo? I guess
I'll find out later tonight, and I can just unmount and remount.

I think this is all good with just a simple 'snapmirror break ...' but
then when we get the chance to rejoin the other two nodes into the
cluster down the line, I would asusme I just have to (maybe) wipe the
old nodes and rejoin them one at a time. Mostly because by that point
I can't have the original source volumes come up and cause us to lose
all the writes that have happened on the now writeable destination
volumes.

And of course there's the matter of getting epsilon back up and
working on the two node cluster when I reboot it. Along with all the
LIFs, etc. Not going to be a fun time. Not at all...

And of course we're out of support with Netapp. Sigh...

And who knows if the pair that came down won't lose some disks and end
up losing one or more aggregates as well. Stressful times for sure.

So I'm just venting here, but any suggestions or tricks would be
helpful.

And of course I'm not sure if the cluster switches made it down here
yet.

Never put your DC on the second floor if there isn't a second freight
elevator. Or elevator in general. Sigh...

John
_______________________________________________
Toasters mailing list
Toasters@teaparty.net
https://www.teaparty.net/mailman/listinfo/toasters
Re: 4 node cluster - only two nodes coming up [ In reply to ]
So the NetApp came up without any major problems, and I can see all the volumes on the two nodes that arrived, but now I need to break the snap mirror relationship (done) and I mount the original volume from the junction path, and mount the mirror onto that new path. Not working well, since the two nodes holding that volume are offline.

I suspect I will have to just delete those nodes from the cluster, which is scary. And accept that when those nodes come back down I will have to initialize them and re-add them into the cluster.

John

Sent from my iPhone

> On May 15, 2021, at 6:52 PM, John Stoffel <john@stoffel.org> wrote:
>
> ?
>
> Hi all,
>
> We're in the middle of hell, where our 4-node FAS8060 cluster was
> shutdown cleanly for a move, but only one pair made it onto the truck
> to the new DC. Luckily I have all the volumes snapmirrored between
> the two pairs of nodes and their aggregates.
>
> But now I need to bring up the pair that made the trip, figure out
> which mirrors are source and which are destination on this pair, and
> then break the destination ones so I can promote them to read-write.
>
> This is not something I've practiced, and I wonder that if I have
> volume foo, mounted on /foo, and it's snapmirror is volume foo_sm,
> when I do the break, will it automatically mount to /foo? I guess
> I'll find out later tonight, and I can just unmount and remount.
>
> I think this is all good with just a simple 'snapmirror break ...' but
> then when we get the chance to rejoin the other two nodes into the
> cluster down the line, I would asusme I just have to (maybe) wipe the
> old nodes and rejoin them one at a time. Mostly because by that point
> I can't have the original source volumes come up and cause us to lose
> all the writes that have happened on the now writeable destination
> volumes.
>
> And of course there's the matter of getting epsilon back up and
> working on the two node cluster when I reboot it. Along with all the
> LIFs, etc. Not going to be a fun time. Not at all...
>
> And of course we're out of support with Netapp. Sigh...
>
> And who knows if the pair that came down won't lose some disks and end
> up losing one or more aggregates as well. Stressful times for sure.
>
> So I'm just venting here, but any suggestions or tricks would be
> helpful.
>
> And of course I'm not sure if the cluster switches made it down here
> yet.
>
> Never put your DC on the second floor if there isn't a second freight
> elevator. Or elevator in general. Sigh...
>
> John
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> https://www.teaparty.net/mailman/listinfo/toasters

_______________________________________________
Toasters mailing list
Toasters@teaparty.net
https://www.teaparty.net/mailman/listinfo/toasters
Re: 4 node cluster - only two nodes coming up [ In reply to ]
The two nodes came up ok, the problem is the svms with a root ok on the missing pair of nodes. Escalating with netapp.


Not sure we have the time to wait for elevator repair to bring the missing pair to the new location, ten hours by truck. Been a hellosh weekend.

I wonder if pod sharing rootvols would have saved us some pain? Maybe not since updates wouldn’t be possible.



Sent from my iPhone

> On May 16, 2021, at 2:18 AM, andrei.borzenkov@fujitsu.com wrote:
>
> ?
> You can only bring up two nodes if one of them has epsilon. Otherwise no configuration changes are possible and that includes breaking snap mirror.
>
> If those two nodes do have epsilon, it is just normal procedure to failover LIF. After snap mirror break destinations volumes are not renamed - they remain exactly as they are. Nothing special needs to be done when two remaining nodes arrive - they just join cluster normally.
>
> If these two nodes do not have epsilon, your best bet is to wait for the remaining cluster nodes to arrive. I am not aware of possibility to force epsilon in this case. May be it exists, but you certainly need support case to obtain it and any follow up step.
>
> ???????? Outlook ??? iOS
> ??: ???????????? Toasters <toasters-bounces@teaparty.net> ?? ????? ???????????? John Stoffel <john@stoffel.org>
> ??????????: ???????????, ??? 16, 2021 04:54
> ????: <Toasters@teaparty.net>
> ????: 4 node cluster - only two nodes coming up
>
>
>
> Hi all,
>
> We're in the middle of hell, where our 4-node FAS8060 cluster was
> shutdown cleanly for a move, but only one pair made it onto the truck
> to the new DC. Luckily I have all the volumes snapmirrored between
> the two pairs of nodes and their aggregates.
>
> But now I need to bring up the pair that made the trip, figure out
> which mirrors are source and which are destination on this pair, and
> then break the destination ones so I can promote them to read-write.
>
> This is not something I've practiced, and I wonder that if I have
> volume foo, mounted on /foo, and it's snapmirror is volume foo_sm,
> when I do the break, will it automatically mount to /foo? I guess
> I'll find out later tonight, and I can just unmount and remount.
>
> I think this is all good with just a simple 'snapmirror break ...' but
> then when we get the chance to rejoin the other two nodes into the
> cluster down the line, I would asusme I just have to (maybe) wipe the
> old nodes and rejoin them one at a time. Mostly because by that point
> I can't have the original source volumes come up and cause us to lose
> all the writes that have happened on the now writeable destination
> volumes.
>
> And of course there's the matter of getting epsilon back up and
> working on the two node cluster when I reboot it. Along with all the
> LIFs, etc. Not going to be a fun time. Not at all...
>
> And of course we're out of support with Netapp. Sigh...
>
> And who knows if the pair that came down won't lose some disks and end
> up losing one or more aggregates as well. Stressful times for sure.
>
> So I'm just venting here, but any suggestions or tricks would be
> helpful.
>
> And of course I'm not sure if the cluster switches made it down here
> yet.
>
> Never put your DC on the second floor if there isn't a second freight
> elevator. Or elevator in general. Sigh...
>
> John
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> https://www.teaparty.net/mailman/listinfo/toasters
Re: 4 node cluster - only two nodes coming up [ In reply to ]
Hi Tim,
Thanks for the offer to help. We will just have to see how long it will take to reunite our cluster pairs, though I’d be happy to just dump the missing pair and handle the data loss.

Which won’t be much if anything at all.

Sent from my iPhone

> On May 15, 2021, at 7:04 PM, Timothy Naple <tnaple@berkcom.com> wrote:
>
> ?
> John,
>
> If it were me, I would take it one step at a time and first get the systems physically in place, cabled up and clusters switches up and running and once you can login on console or SSH then start looking at the aggregates, LIF's, cluster epsilon/quorum and which volumes are source, etc. Keep me posted if you hit any major roadblocks and I can try to help out.
>
> Thank you,
> Tim
>
> From: Toasters <toasters-bounces@teaparty.net> on behalf of John Stoffel <john@stoffel.org>
> Sent: Saturday, May 15, 2021 6:47 PM
> To: <Toasters@teaparty.net> <Toasters@teaparty.net>
> Subject: 4 node cluster - only two nodes coming up
>
>
>
> Hi all,
>
> We're in the middle of hell, where our 4-node FAS8060 cluster was
> shutdown cleanly for a move, but only one pair made it onto the truck
> to the new DC. Luckily I have all the volumes snapmirrored between
> the two pairs of nodes and their aggregates.
>
> But now I need to bring up the pair that made the trip, figure out
> which mirrors are source and which are destination on this pair, and
> then break the destination ones so I can promote them to read-write.
>
> This is not something I've practiced, and I wonder that if I have
> volume foo, mounted on /foo, and it's snapmirror is volume foo_sm,
> when I do the break, will it automatically mount to /foo? I guess
> I'll find out later tonight, and I can just unmount and remount.
>
> I think this is all good with just a simple 'snapmirror break ...' but
> then when we get the chance to rejoin the other two nodes into the
> cluster down the line, I would asusme I just have to (maybe) wipe the
> old nodes and rejoin them one at a time. Mostly because by that point
> I can't have the original source volumes come up and cause us to lose
> all the writes that have happened on the now writeable destination
> volumes.
>
> And of course there's the matter of getting epsilon back up and
> working on the two node cluster when I reboot it. Along with all the
> LIFs, etc. Not going to be a fun time. Not at all...
>
> And of course we're out of support with Netapp. Sigh...
>
> And who knows if the pair that came down won't lose some disks and end
> up losing one or more aggregates as well. Stressful times for sure.
>
> So I'm just venting here, but any suggestions or tricks would be
> helpful.
>
> And of course I'm not sure if the cluster switches made it down here
> yet.
>
> Never put your DC on the second floor if there isn't a second freight
> elevator. Or elevator in general. Sigh...
>
> John
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> https://www.teaparty.net/mailman/listinfo/toasters
Re: 4 node cluster - only two nodes coming up [ In reply to ]
Well, this is the 1 case, where Load-Sharing Mirrors would have been
helpful...

Too late now, though.


Sebastian


On 17.05.2021 02:01, John Stoffel wrote:
> The two nodes came up ok, the problem is the svms with a root ok on
> the missing pair of nodes.  Escalating with netapp.
>
>
> Not sure we have the time to wait for elevator repair to bring the
> missing pair to the new location, ten hours by truck.  Been a hellosh
> weekend.
>
> I wonder if pod sharing rootvols would have saved us some pain?  Maybe
> not since updates wouldn’t be possible.
>
>
>
> Sent from my iPhone
>
>> On May 16, 2021, at 2:18 AM, andrei.borzenkov@fujitsu.com wrote:
>>
>> ?
>> You can only bring up two nodes if one of them has epsilon. Otherwise
>> no configuration changes are possible and that includes breaking snap
>> mirror.
>>
>> If those two nodes do have epsilon, it is just normal procedure to
>> failover LIF. After snap mirror break destinations volumes are not
>> renamed - they remain exactly as they are. Nothing special needs to
>> be done when two remaining nodes arrive - they just join cluster
>> normally.
>>
>> If these two nodes do not have epsilon, your best bet is to wait for
>> the remaining cluster nodes to arrive. I am not aware of possibility
>> to force epsilon in this case. May be it exists, but you certainly
>> need support case to obtain it and any follow up step.
>>
>> ???????? Outlook ??? iOS <https://aka.ms/o0ukef>
>> ------------------------------------------------------------------------
>> *??:* ???????????? Toasters <toasters-bounces@teaparty.net> ?? ?????
>> ???????????? John Stoffel <john@stoffel.org>
>> *??????????:* ???????????, ??? 16, 2021 04:54
>> *????:* <Toasters@teaparty.net>
>> *????:* 4 node cluster - only two nodes coming up
>>
>>
>> Hi all,
>>
>> We're in the middle of hell, where our 4-node FAS8060 cluster was
>> shutdown cleanly for a move, but only one pair made it onto the truck
>> to the new DC.  Luckily I have all the volumes snapmirrored between
>> the two pairs of nodes and their aggregates.
>>
>> But now I need to bring up the pair that made the trip, figure out
>> which mirrors are source and which are destination on this pair, and
>> then break the destination ones so I can promote them to read-write.
>>
>> This is not something I've practiced, and I wonder that if I have
>> volume foo, mounted on /foo, and it's snapmirror is volume foo_sm,
>> when I do the break, will it automatically mount to /foo?  I guess
>> I'll find out later tonight, and I can just unmount and remount.
>>
>> I think this is all good with just a simple 'snapmirror break ...' but
>> then when we get the chance to rejoin the other two nodes into the
>> cluster down the line, I would asusme I just have to (maybe) wipe the
>> old nodes and rejoin them one at a time.  Mostly because by that point
>> I can't have the original source volumes come up and cause us to lose
>> all the writes that have happened on the now writeable destination
>> volumes.
>>
>> And of course there's the matter of getting epsilon back up and
>> working on the two node cluster when I reboot it. Along with all the
>> LIFs, etc.  Not going to be a fun time.  Not at all...
>>
>> And of course we're out of support with Netapp. Sigh...
>>
>> And who knows if the pair that came down won't lose some disks and end
>> up losing one or more aggregates as well. Stressful times for sure.
>>
>> So I'm just venting here, but any suggestions or tricks would be
>> helpful.
>>
>> And of course I'm not sure if the cluster switches made it down here
>> yet.
>>
>> Never put your DC on the second floor if there isn't a second freight
>> elevator.  Or elevator in general.  Sigh...
>>
>> John
>> _______________________________________________
>> Toasters mailing list
>> Toasters@teaparty.net
>> https://www.teaparty.net/mailman/listinfo/toasters
>> <https://www.teaparty.net/mailman/listinfo/toasters>
>
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> https://www.teaparty.net/mailman/listinfo/toasters
Re: 4 node cluster - only two nodes coming up [ In reply to ]
I had something like this a while back.

I ended up just creating a new 1GB volume and the converting it to the root
vol (volume make-vsroot)

--tmac

*Tim McCarthy, **Principal Consultant*

*Proud Member of the #NetAppATeam <https://twitter.com/NetAppATeam>*

*I Blog at TMACsRack <https://tmacsrack.wordpress.com/>*



On Sun, May 16, 2021 at 8:05 PM John Stoffel <john@stoffel.org> wrote:

> The two nodes came up ok, the problem is the svms with a root ok on the
> missing pair of nodes. Escalating with netapp.
>
>
> Not sure we have the time to wait for elevator repair to bring the missing
> pair to the new location, ten hours by truck. Been a hellosh weekend.
>
> I wonder if pod sharing rootvols would have saved us some pain? Maybe not
> since updates wouldn’t be possible.
>
>
>
> Sent from my iPhone
>
> On May 16, 2021, at 2:18 AM, andrei.borzenkov@fujitsu.com wrote:
>
> ?
> You can only bring up two nodes if one of them has epsilon. Otherwise no
> configuration changes are possible and that includes breaking snap mirror.
>
> If those two nodes do have epsilon, it is just normal procedure to
> failover LIF. After snap mirror break destinations volumes are not renamed
> - they remain exactly as they are. Nothing special needs to be done when
> two remaining nodes arrive - they just join cluster normally.
>
> If these two nodes do not have epsilon, your best bet is to wait for the
> remaining cluster nodes to arrive. I am not aware of possibility to force
> epsilon in this case. May be it exists, but you certainly need support case
> to obtain it and any follow up step.
>
> ???????? Outlook ??? iOS <https://aka.ms/o0ukef>
> ------------------------------
> *??:* ???????????? Toasters <toasters-bounces@teaparty.net> ?? ?????
> ???????????? John Stoffel <john@stoffel.org>
> *??????????:* ???????????, ??? 16, 2021 04:54
> *????:* <Toasters@teaparty.net>
> *????:* 4 node cluster - only two nodes coming up
>
>
>
> Hi all,
>
> We're in the middle of hell, where our 4-node FAS8060 cluster was
> shutdown cleanly for a move, but only one pair made it onto the truck
> to the new DC. Luckily I have all the volumes snapmirrored between
> the two pairs of nodes and their aggregates.
>
> But now I need to bring up the pair that made the trip, figure out
> which mirrors are source and which are destination on this pair, and
> then break the destination ones so I can promote them to read-write.
>
> This is not something I've practiced, and I wonder that if I have
> volume foo, mounted on /foo, and it's snapmirror is volume foo_sm,
> when I do the break, will it automatically mount to /foo? I guess
> I'll find out later tonight, and I can just unmount and remount.
>
> I think this is all good with just a simple 'snapmirror break ...' but
> then when we get the chance to rejoin the other two nodes into the
> cluster down the line, I would asusme I just have to (maybe) wipe the
> old nodes and rejoin them one at a time. Mostly because by that point
> I can't have the original source volumes come up and cause us to lose
> all the writes that have happened on the now writeable destination
> volumes.
>
> And of course there's the matter of getting epsilon back up and
> working on the two node cluster when I reboot it. Along with all the
> LIFs, etc. Not going to be a fun time. Not at all...
>
> And of course we're out of support with Netapp. Sigh...
>
> And who knows if the pair that came down won't lose some disks and end
> up losing one or more aggregates as well. Stressful times for sure.
>
> So I'm just venting here, but any suggestions or tricks would be
> helpful.
>
> And of course I'm not sure if the cluster switches made it down here
> yet.
>
> Never put your DC on the second floor if there isn't a second freight
> elevator. Or elevator in general. Sigh...
>
> John
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> https://www.teaparty.net/mailman/listinfo/toasters
>
> _______________________________________________
> Toasters mailing list
> Toasters@teaparty.net
> https://www.teaparty.net/mailman/listinfo/toasters
Re: 4 node cluster - only two nodes coming up [ In reply to ]
Sebastian> Well, this is the 1 case, where Load-Sharing Mirrors would
Sebastian> have been helpful... Too late now, though.

Maybe... it's not clear if it would have helped all that much. What
we should have done in hindsight, since we had the capacity, would be
to split off two nodes of the cluster ahead of the move, then
snapmirror between them.

It still would have been a pain, but recovery would have been
simpler. We're still working on issues, but most things are working.

John



Sebastian> Sebastian

Sebastian> On 17.05.2021 02:01, John Stoffel wrote:

Sebastian> The two nodes came up ok, the problem is the svms with a root ok on the missing pair of nodes.  Escalating with netapp.

Sebastian> Not sure we have the time to wait for elevator repair to bring the missing pair to the new location, ten hours by truck.  Been a hellosh
Sebastian> weekend.

Sebastian> I wonder if pod sharing rootvols would have saved us some pain?  Maybe not since updates wouldn’t be possible.  

Sebastian> Sent from my iPhone

Sebastian> On May 16, 2021, at 2:18 AM, andrei.borzenkov@fujitsu.com wrote:

Sebastian> You can only bring up two nodes if one of them has epsilon. Otherwise no configuration changes are possible and that includes
Sebastian> breaking snap mirror.

Sebastian> If those two nodes do have epsilon, it is just normal procedure to failover LIF. After snap mirror break destinations volumes are not
Sebastian> renamed - they remain exactly as they are. Nothing special needs to be done when two remaining nodes arrive - they just join cluster
Sebastian> normally.

Sebastian> If these two nodes do not have epsilon, your best bet is to wait for the remaining cluster nodes to arrive. I am not aware of
Sebastian> possibility to force epsilon in this case. May be it exists, but you certainly need support case to obtain it and any follow up step.

Sebastian> ???????? Outlook ??? iOS
Sebastian> -------------------------------------------------------------------------------------------------------------------------------------
Sebastian> ??: ???????????? Toasters <toasters-bounces@teaparty.net> ?? ????? ???????????? John Stoffel <john@stoffel.org>
Sebastian> ??????????: ???????????, ??? 16, 2021 04:54
Sebastian> ????: <Toasters@teaparty.net>
Sebastian> ????: 4 node cluster - only two nodes coming up
Sebastian>  

Sebastian> Hi all,

Sebastian> We're in the middle of hell, where our 4-node FAS8060 cluster was
Sebastian> shutdown cleanly for a move, but only one pair made it onto the truck
Sebastian> to the new DC.  Luckily I have all the volumes snapmirrored between
Sebastian> the two pairs of nodes and their aggregates. 

Sebastian> But now I need to bring up the pair that made the trip, figure out
Sebastian> which mirrors are source and which are destination on this pair, and
Sebastian> then break the destination ones so I can promote them to read-write.

Sebastian> This is not something I've practiced, and I wonder that if I have
Sebastian> volume foo, mounted on /foo, and it's snapmirror is volume foo_sm,
Sebastian> when I do the break, will it automatically mount to /foo?  I guess
Sebastian> I'll find out later tonight, and I can just unmount and remount. 

Sebastian> I think this is all good with just a simple 'snapmirror break ...' but
Sebastian> then when we get the chance to rejoin the other two nodes into the
Sebastian> cluster down the line, I would asusme I just have to (maybe) wipe the
Sebastian> old nodes and rejoin them one at a time.  Mostly because by that point
Sebastian> I can't have the original source volumes come up and cause us to lose
Sebastian> all the writes that have happened on the now writeable destination
Sebastian> volumes. 

Sebastian> And of course there's the matter of getting epsilon back up and
Sebastian> working on the two node cluster when I reboot it.  Along with all the
Sebastian> LIFs, etc.  Not going to be a fun time.  Not at all...

Sebastian> And of course we're out of support with Netapp.  Sigh...

Sebastian> And who knows if the pair that came down won't lose some disks and end
Sebastian> up losing one or more aggregates as well.  Stressful times for sure.

Sebastian> So I'm just venting here, but any suggestions or tricks would be
Sebastian> helpful.

Sebastian> And of course I'm not sure if the cluster switches made it down here
Sebastian> yet.

Sebastian> Never put your DC on the second floor if there isn't a second freight
Sebastian> elevator.  Or elevator in general.  Sigh...

Sebastian> John
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Re: 4 node cluster - only two nodes coming up [ In reply to ]
>>>>> "tmac" == tmac <tmacmd@gmail.com> writes:

tmac> I had something like this a while back.
tmac> I ended up just creating a new 1GB volume and the converting it to the root vol (volume make-vsroot)

Since we have a snapmirror of the old rootvol, I was able to promote
it once I had broken the copy. So we're ok now, though still fighting
other issues.

John
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