Remember that WAFL still writes across the
entire aggregate. Having a slower RAID group in an aggregate of faster raid
groups would be akin to having a slower disk in a RG of faster disks, would it
not?
Glenn
From:
owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Brosseau, Paul
Sent: Wednesday, September 20,
2006 8:05 PM
To: Jeff Mery;
toasters@mathworks.com
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
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