On 13/06/16 18:53, Marc A Kaplan wrote:
How do you set the size of a ZFS file that is simulating a GPFS disk?
How do "tell" GPFS about that?
How efficient is this layering, compared to just giving GPFS direct
access to the same kind of LUNs that ZFS is using?
Hmmm... to partially answer my question, I do something similar, but
strictly for testing non-performance critical GPFS functions.
On any file system one can:
dd if=/dev/zero of=/fakedisks/d3 count=1 bs=1M seek=3000 # create a
fake 3GB disk for GPFS
Then use a GPFS nsd configuration record like this:
%nsd: nsd=d3 device=/fakedisks/d3 usage=dataOnly pool=xtra
servers=bog-xxx
Which starts out as sparse and the filesystem will dynamically "grow" as
GPFS writes to it...
But I have no idea how well this will work for a critical "production"
system...
For "testing" purposes I just create a logical volume and map it through
to my bunch of GPFS KVM instances as a disk. Works a treat and SSD's are
silly money these days so for testing performance is just fine. There
was a 960GB SanDisk on offer for 160GBP last month.
JAB.
--
Jonathan A. Buzzard Email: jonathan (at) buzzard.me.uk
Fife, United Kingdom.
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