Mixing disk sizes in an aggregate is not a problem as long as you create RAID groups for each kind of disk. WAFL creates stripes at the RAID group level. For best results create complete RAID groups each time you add disks to an aggregate.
Paulb
________________________________
From: Jeff Mery [mailto:jeff.mery@ni.com] Sent: Wednesday, September 20, 2006 3:30 PM To: toasters@mathworks.com Subject: Mixed disk sizes within a single aggregate
Greetings fellow toasters! <Background> We're looking at moving our 2 FAS940 systems from tradtional volumes to flexvols + aggregates. </Background>
It would seem to me that the same rules and guidelines for creating traditional volumes now apply directly to the aggregate level (for the most part). By rules and guidelines I mean things like trying not to mix disk sizes, try to avoid volumes (now aggregates?) that span FC adapters, etc.
Are any of these things still a concern on modern versions of ONTAP (7+)? Does anyone have any best practices they'd be willing to share in regards to aggregate creation? NOW says "make them as big as possible using as many spindles as possible", but that doesn't really help much. We use our filers for unstructured data only; cifs + nfs but no databases, no snapmirror, no snapvault, etc..
TIA, Jeff Mery - MCSE, MCP National Instruments
------------------------------------------------------------------------ - "Allow me to extol the virtues of the Net Fairy, and of all the fantastic dorks that make the nice packets go from here to there. Amen." TB - Penny Arcade ------------------------------------------------------------------------ -
What about aggregates across FC adapters? Recommended, not recommended, or not an issue?
Kelley
Kelley R. Green IT Specialist Global Technology Services - Storage Access Line 801-415-0449 Cell 801-916-1273 e-mail: krgreen@us.ibm.com
"Brosseau, Paul" Paul.Brosseau@netapp.com Sent by: owner-toasters@mathworks.com 09/20/2006 06:04 PM
To "Jeff Mery" jeff.mery@ni.com, toasters@mathworks.com cc
Subject RE: Mixed disk sizes within a single aggregate
Mixing disk sizes in an aggregate is not a problem as long as you create RAID groups for each kind of disk. WAFL creates stripes at the RAID group level. For best results create complete RAID groups each time you add disks to an aggregate.
Paulb
From: Jeff Mery [mailto:jeff.mery@ni.com] Sent: Wednesday, September 20, 2006 3:30 PM To: toasters@mathworks.com Subject: Mixed disk sizes within a single aggregate
Greetings fellow toasters! <Background> We're looking at moving our 2 FAS940 systems from tradtional volumes to flexvols + aggregates. </Background>
It would seem to me that the same rules and guidelines for creating traditional volumes now apply directly to the aggregate level (for the most part). By rules and guidelines I mean things like trying not to mix disk sizes, try to avoid volumes (now aggregates?) that span FC adapters, etc.
Are any of these things still a concern on modern versions of ONTAP (7+)? Does anyone have any best practices they'd be willing to share in regards to aggregate creation? NOW says "make them as big as possible using as many spindles as possible", but that doesn't really help much. We use our filers for unstructured data only; cifs + nfs but no databases, no snapmirror, no snapvault, etc..
TIA, Jeff Mery - MCSE, MCP National Instruments
------------------------------------------------------------------------- "Allow me to extol the virtues of the Net Fairy, and of all the fantastic dorks that make the nice packets go from here to there. Amen." TB - Penny Arcade -------------------------------------------------------------------------
Just bear in mind that any aggregate will only perform as well as the slowest RAID group. Spanning an aggregate across multiple adaptors will improve fault tolerance. WAFL will automatically select disks across adapters to maximise that.
________________________________
From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Kelley Green Sent: 21 September 2006 05:07 To: Brosseau, Paul Cc: Jeff Mery; owner-toasters@mathworks.com; toasters@mathworks.com Subject: RE: Mixed disk sizes within a single aggregate
What about aggregates across FC adapters? Recommended, not recommended, or not an issue?
Kelley
Kelley R. Green IT Specialist Global Technology Services - Storage Access Line 801-415-0449 Cell 801-916-1273 e-mail: krgreen@us.ibm.com
"Brosseau, Paul" Paul.Brosseau@netapp.com Sent by: owner-toasters@mathworks.com
09/20/2006 06:04 PM
To "Jeff Mery" jeff.mery@ni.com, toasters@mathworks.com cc Subject RE: Mixed disk sizes within a single aggregate
Mixing disk sizes in an aggregate is not a problem as long as you create RAID groups for each kind of disk. WAFL creates stripes at the RAID group level. For best results create complete RAID groups each time you add disks to an aggregate.
Paulb
________________________________
From: Jeff Mery [mailto:jeff.mery@ni.com] Sent: Wednesday, September 20, 2006 3:30 PM To: toasters@mathworks.com Subject: Mixed disk sizes within a single aggregate
Greetings fellow toasters! <Background> We're looking at moving our 2 FAS940 systems from tradtional volumes to flexvols + aggregates. </Background>
It would seem to me that the same rules and guidelines for creating traditional volumes now apply directly to the aggregate level (for the most part). By rules and guidelines I mean things like trying not to mix disk sizes, try to avoid volumes (now aggregates?) that span FC adapters, etc.
Are any of these things still a concern on modern versions of ONTAP (7+)? Does anyone have any best practices they'd be willing to share in regards to aggregate creation? NOW says "make them as big as possible using as many spindles as possible", but that doesn't really help much. We use our filers for unstructured data only; cifs + nfs but no databases, no snapmirror, no snapvault, etc..
TIA, Jeff Mery - MCSE, MCP National Instruments
------------------------------------------------------------------------ - "Allow me to extol the virtues of the Net Fairy, and of all the fantastic dorks that make the nice packets go from here to there. Amen." TB - Penny Arcade ------------------------------------------------------------------------ -
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On 9/20/06, Brosseau, Paul Paul.Brosseau@netapp.com wrote:
Mixing disk sizes in an aggregate is not a problem as long as you create RAID groups for each kind of disk. WAFL creates stripes at the RAID group level. For best results create complete RAID groups each time you add disks to an aggregate.
Paulb
Paul and others, Is there way to force an aggregate to start a new RAID group when an existing RAID group is not completely full. Here's a situation FAS270 with 2 shelves with 144GB FC drives. RG size is set to 16 for a single aggregate with 26 disks (2 spares). This resulted in 2 RAID groups, 1 with 16 disks and the other with 10. Now we plan to add a 3rd shelf with 300GB FC drives. If we do the regular "aggr add" it will first add the 2 spare 144GB drives, then add 4 new 300GB drives by right sizing them to match the 144GB ones. In order to maximize the capacity on this aggregate, I'd prefer to add 12 of the new drives to a new RAID group but within the same aggregate. Is something like this possible?
Haven't tried this as we don't have the new shelf yet, but can I reduce the raidsize option for the aggregate from 16 to 12, then add the 2 existing spares such that that the 2nd raid-group is now full based on raidsize=12 option. Now add the new shelf and run "aggr add aggr0 12" to add 12 new 300GB drive leaving 2 spares? RAID group /aggr0/plex0/rg0 - 16 disks (144GB each) RAID group /aggr0/plex0/rg1 - 12 disks (144GB each) <-- add the existing 2 spares RAID group /aggr0/plex0/rg2 - 12 disks (300GB each) Spares - two new 300GB drives.
I think it would work, any comments?
-G
"Sto" == Sto Rage© <" netbacker@gmail.com> writes:
Sto> Paul and others,
Sto> Is there way to force an aggregate to start a new RAID group Sto> when an existing RAID group is not completely full.
Certainly, just specify explicity which disks you want in the aggregate:
aggr create aggr300gb -d 12@300
See the output of 'aggr create<return>'
John
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Brosseau, Paul -
John Stoffel -
Kelley Green -
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Sto Rage©