Hi, I know when traditional vols are in use, you don't want to let them get too close to full because performance will be affected.
But what about using FlexVols and Aggrs ?
I have a few Aggrs that are at 100%. But the FlexVols in those Aggrs are mostly under 50%.
I had a NetApp support person tell me that its bad to have Aggrs at 100%, even if the FlexVols are not full.
What's the answer here. Does having Aggrs at 100% because the FlexVols contained in them are sized to fill the Aggr present a performance issue ?
I would think that as long as the flexvols are not close to full, its ok to have the aggr's at 100%.
Thanks,
Paul
I believe it has to do with "recoverability" to a point...
There are snapshots at the AGGR level, if you max out the flexvols to 100%, there is no real room left for aggr snaps.
You can turn off aggr snaps and set the aggr snap reserve to 0%, although I think it is not a best practice...
--tmac
On Jan 31, 2008 10:25 AM, Paul Letta letta@jlab.org wrote:
Hi, I know when traditional vols are in use, you don't want to let them get too close to full because performance will be affected.
But what about using FlexVols and Aggrs ?
I have a few Aggrs that are at 100%. But the FlexVols in those Aggrs are mostly under 50%.
I had a NetApp support person tell me that its bad to have Aggrs at 100%, even if the FlexVols are not full.
What's the answer here. Does having Aggrs at 100% because the FlexVols contained in them are sized to fill the Aggr present a performance issue ?
I would think that as long as the flexvols are not close to full, its ok to have the aggr's at 100%.
Thanks,
Paul
If we are never going to use an aggr snapshot, why do we need them ? We do have the aggr snap reserves set to 0 and do not do aggr level snap shots. Our flexvols have snap scheds that meets the needs of the data on that particular flexvol.
What are the risks with this configuration ?
Thanks,
Paul
tmac wrote:
I believe it has to do with "recoverability" to a point...
There are snapshots at the AGGR level, if you max out the flexvols to 100%, there is no real room left for aggr snaps.
You can turn off aggr snaps and set the aggr snap reserve to 0%, although I think it is not a best practice...
--tmac
I believe SyncMirror is the only product that uses aggregate level snapshot. Snaprestore also would let you restore the whole aggregate back from a snap, should you need to do that for some reason. Personally, I turn them off as well.
Cheers Chris
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-----Original Message-----
From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Paul Letta Sent: 31 January 2008 16:54 To: tmac Cc: toasters@mathworks.com Subject: Re: Aggr's at 100% with FlexVols
If we are never going to use an aggr snapshot, why do we need them ? We
do have the aggr snap reserves set to 0 and do not do aggr level snap shots. Our flexvols have snap scheds that meets the needs of the data on that particular flexvol.
What are the risks with this configuration ?
Thanks,
Paul
tmac wrote:
I believe it has to do with "recoverability" to a point...
There are snapshots at the AGGR level, if you max out the flexvols to 100%, there is no real room left for aggr snaps.
You can turn off aggr snaps and set the aggr snap reserve to 0%, although I think it is not a best practice...
--tmac
There was also some performance aspect with aggrs at 100%, but unsure if that is still the case - NetApp is really good at addressing bugs with performance.
The benefit of aggr snapshots aren't really great: you can only roll back the entire aggr (every volume within it as a byproduct) with those snapshots, unless there have been significant changes.
________________________________
From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of tmac Sent: Thursday, January 31, 2008 11:44 AM To: letta@jlab.org Cc: toasters@mathworks.com Subject: Re: Aggr's at 100% with FlexVols
I believe it has to do with "recoverability" to a point...
There are snapshots at the AGGR level, if you max out the flexvols to 100%, there is no real room left for aggr snaps.
You can turn off aggr snaps and set the aggr snap reserve to 0%, although I think it is not a best practice...
--tmac
On Jan 31, 2008 10:25 AM, Paul Letta letta@jlab.org wrote:
Hi, I know when traditional vols are in use, you don't want to let them get too close to full because performance will be affected.
But what about using FlexVols and Aggrs ?
I have a few Aggrs that are at 100%. But the FlexVols in those Aggrs are mostly under 50%.
I had a NetApp support person tell me that its bad to have Aggrs at 100%, even if the FlexVols are not full.
What's the answer here. Does having Aggrs at 100% because the FlexVols contained in them are sized to fill the Aggr present a performance issue ?
I would think that as long as the flexvols are not close to full, its ok to have the aggr's at 100%.
Thanks,
Paul
we have always turned off aggregate snaps and reserve, with tons of flex vols what does an aggregate snap buy you? i would never snap restore an aggregate and roll back 50+ unrelated volumes. each volume has its own snap schedule and is vaulted to another filer.
maybe im missing something but in 3 years of running 7.x i've never even thought about restoring an entire aggregate.
-- Daniel Leeds Manager, Storage Operations Edmunds, Inc. 1620 26th Street, Suite 400 South Santa Monica, CA 90404
310-309-4999 desk 310-430-0536 cell
-----Original Message----- From: owner-toasters@mathworks.com on behalf of tmac Sent: Thu 1/31/2008 8:43 AM To: letta@jlab.org Cc: toasters@mathworks.com Subject: Re: Aggr's at 100% with FlexVols
I believe it has to do with "recoverability" to a point...
There are snapshots at the AGGR level, if you max out the flexvols to 100%, there is no real room left for aggr snaps.
You can turn off aggr snaps and set the aggr snap reserve to 0%, although I think it is not a best practice...
--tmac
On Jan 31, 2008 10:25 AM, Paul Letta letta@jlab.org wrote:
Hi, I know when traditional vols are in use, you don't want to let them get too close to full because performance will be affected. But what about using FlexVols and Aggrs ? I have a few Aggrs that are at 100%. But the FlexVols in those Aggrs are mostly under 50%. I had a NetApp support person tell me that its bad to have Aggrs at 100%, even if the FlexVols are not full. What's the answer here. Does having Aggrs at 100% because the FlexVols contained in them are sized to fill the Aggr present a performance issue ? I would think that as long as the flexvols are not close to full, its ok to have the aggr's at 100%. Thanks, Paul
You have it opposite. Best practice says the Aggregate threshold max usage should be 80% for best performance, 90% at most. The reasoning is Data ONtap has to search much harder to find free blocks to write with, thus CPU / other resources are consumed in this search.
FlexVols at 100% usage do not have any detrimental impact other than running out of space or throwing filer/dfm alerts, so I like to keep those at 95% or less if they contain static block-level data.
You should reduce the usage of your aggregate immediately!
HTH,
Hadrian
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Paul Letta Sent: Thursday, January 31, 2008 7:25 AM To: toasters@mathworks.com Subject: Aggr's at 100% with FlexVols
Hi, I know when traditional vols are in use, you don't want to let them get too close to full because performance will be affected.
But what about using FlexVols and Aggrs ?
I have a few Aggrs that are at 100%. But the FlexVols in those Aggrs are mostly under 50%.
I had a NetApp support person tell me that its bad to have Aggrs at 100%, even if the FlexVols are not full.
What's the answer here. Does having Aggrs at 100% because the FlexVols contained in them are sized to fill the Aggr present a performance issue ?
I would think that as long as the flexvols are not close to full, its ok to have the aggr's at 100%.
Thanks,
Paul
I have actually run into conditions where dfm reported the aggregate to be over-committed. That's when I realized that snap reserve by default is taking up space for the aggregate. A quick consult with netapp confirmed my suspicion that you do not need aggr reserve space if you are not intending to do an aggr snap. Try setting the aggr reserve space to 0 and you should be fine.
Bob K.
Robert Kleinbrahm Senior Network Engineer First Republic Bank San Frincisco, CA. 94111 (415) 288.1478 rkleinbrahm@firstrepublic.com "Just agree with me and we'll both be right." -----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Paul Letta Sent: Thursday, January 31, 2008 7:25 AM To: toasters@mathworks.com Subject: Aggr's at 100% with FlexVols
Hi, I know when traditional vols are in use, you don't want to let them get too close to full because performance will be affected.
But what about using FlexVols and Aggrs ?
I have a few Aggrs that are at 100%. But the FlexVols in those Aggrs are mostly under 50%.
I had a NetApp support person tell me that its bad to have Aggrs at 100%, even if the FlexVols are not full.
What's the answer here. Does having Aggrs at 100% because the FlexVols contained in them are sized to fill the Aggr present a performance issue ?
I would think that as long as the flexvols are not close to full, its ok
to have the aggr's at 100%.
Thanks,
Paul
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During update from 7.0 to 7.2 we hit the issue of 100% full aggregate - apparently 7.2 requires more space for metadata which suddenly made aggregate overcommitted and turned off space reservation on some of contained FlexVols. As those hosted LUNs it was not exactly the desired result :)
Resolution was to decrease size of overcommitted FlexVols until space reservation was enabled again. So you may want to leave some safety margin on your aggregate anyway.
С уважением / With best regards / Mit freundlichen Grüβen
--- Andrey Borzenkov Senior system engineer -----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Paul Letta Sent: Thursday, January 31, 2008 6:25 PM To: toasters@mathworks.com Subject: Aggr's at 100% with FlexVols
Hi, I know when traditional vols are in use, you don't want to let them get too close to full because performance will be affected.
But what about using FlexVols and Aggrs ?
I have a few Aggrs that are at 100%. But the FlexVols in those Aggrs are mostly under 50%.
I had a NetApp support person tell me that its bad to have Aggrs at 100%, even if the FlexVols are not full.
What's the answer here. Does having Aggrs at 100% because the FlexVols contained in them are sized to fill the Aggr present a performance issue ?
I would think that as long as the flexvols are not close to full, its ok to have the aggr's at 100%.
Thanks,
Paul
Hi,
don't know if i am right, but i prefer to have a look at "aggr show_space"
There one can see the "Space allocated to volumes in the aggregate".
As long as there are still free blocks i do not worry about performance although "df -Ah" shows >95%. Nevertheless we always try not to go that far, for reasons of security (e.g. strong growth of a volume due to application-traces). If this is wrong, please correct me.
Best Regards
Jochen
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Borzenkov, Andrey Sent: Friday, February 01, 2008 7:17 AM To: letta@jlab.org; toasters@mathworks.com Subject: RE: Aggr's at 100% with FlexVols
During update from 7.0 to 7.2 we hit the issue of 100% full aggregate - apparently 7.2 requires more space for metadata which suddenly made aggregate overcommitted and turned off space reservation on some of contained FlexVols. As those hosted LUNs it was not exactly the desired result :)
Resolution was to decrease size of overcommitted FlexVols until space reservation was enabled again. So you may want to leave some safety margin on your aggregate anyway.
�� ��ӧѧا֧ߧڧ֧� / With best regards / Mit freundlichen Gr����en
--- Andrey Borzenkov Senior system engineer -----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Paul Letta Sent: Thursday, January 31, 2008 6:25 PM To: toasters@mathworks.com Subject: Aggr's at 100% with FlexVols
Hi, I know when traditional vols are in use, you don't want to let them get too close to full because performance will be affected.
But what about using FlexVols and Aggrs ?
I have a few Aggrs that are at 100%. But the FlexVols in those Aggrs are mostly under 50%.
I had a NetApp support person tell me that its bad to have Aggrs at 100%, even if the FlexVols are not full.
What's the answer here. Does having Aggrs at 100% because the FlexVols contained in them are sized to fill the Aggr present a performance issue ?
I would think that as long as the flexvols are not close to full, its ok to have the aggr's at 100%.
Thanks,
Paul
We've been told that a fully flex-vol'd aggregate can cause issues with guaranteed reservations due to metadata shortages.
Seems the aggregate will randomly turn off volume reservations if it has no room for aggregate-level metadata, though I'm not entirely certain of what that is made. We've been bitten by it three separate times that I know of, possibly more.
What really hurts is they recommend 5% overhead for this, but with a default 10TB aggregate that's 500GB of metadata overhead. Ouch.
I *think* the original concept for aggregate snapshots was part of Prospero, though I'm not aware that this went anywhere.
Jeff Kennedy QCT Engineering Compute 858-651-6592
-----Original Message----- From: owner-toasters@mathworks.com
[mailto:owner-toasters@mathworks.com]
On Behalf Of Paul Letta Sent: Thursday, January 31, 2008 7:25 AM To: toasters@mathworks.com Subject: Aggr's at 100% with FlexVols
Hi, I know when traditional vols are in use, you don't want to let them get too close to full because performance will be affected.
But what about using FlexVols and Aggrs ?
I have a few Aggrs that are at 100%. But the FlexVols in those Aggrs are mostly under 50%.
I had a NetApp support person tell me that its bad to have Aggrs at 100%, even if the FlexVols are not full.
What's the answer here. Does having Aggrs at 100% because the
FlexVols
contained in them are sized to fill the Aggr present a performance
issue
?
I would think that as long as the flexvols are not close to full, its
ok
to have the aggr's at 100%.
Thanks,
Paul
-
Borzenkov, Andrey -
Glenn Walker -
Hadrian Baron -
Holloway, Chris -
Kennedy, Jeffrey -
Kleinbrahm, Robert -
Leeds, Daniel -
Paul Letta -
tmac -
Willeke, Jochen