Thick in prod, thin in the replication filer.
________________________________ From: Jordan Slingerland Jordan.Slingerland@independenthealth.com To: Fred Grieco fredgrieco@yahoo.com; Jeff Mohler speedtoys.racing@gmail.com Cc: "Toasters@teaparty.net" Toasters@teaparty.net Sent: Friday, September 13, 2013 3:23 PM Subject: RE: high CP_reads/writes ratioA
At 87% it is certainly possible that wafl doesn’t have enough contagious free space to write a chain in a single pass…slowing things down substantially. Are your volumes thick provisioned? That could cloud the equation. --JMS From:Fred Grieco [mailto:fredgrieco@yahoo.com] Sent: Friday, September 13, 2013 3:16 PM To: Jordan Slingerland; Jeff Mohler Cc: Toasters@teaparty.net Subject: Re: high CP_reads/writes ratio The prod one is 87%. The replication one is 71% but it was much higher during disaster recovery testing.
I'll run a reallocate measure on the DR side this weekend and see what comes back.
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From:Jordan Slingerland Jordan.Slingerland@independenthealth.com To: Jeff Mohler speedtoys.racing@gmail.com; Fred Grieco fredgrieco@yahoo.com Cc: "Toasters@teaparty.net" Toasters@teaparty.net Sent: Friday, September 13, 2013 3:12 PM Subject: RE: high CP_reads/writes ratio Are your aggregates more then 65-85% full? From:toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] On Behalf Of Jeff Mohler Sent: Friday, September 13, 2013 3:09 PM To: Fred Grieco Cc: Toasters@teaparty.net Subject: Re: high CP_reads/writes ratio Wafl free space fragmentation most likely. Reallocate all volumes in the affected aggregate. Do not reallocate the _aggregate_.
Sent from my iPhone
On Sep 13, 2013, at 1:06 PM, Fred Grieco fredgrieco@yahoo.com wrote: What kinds of things can cause a high CP_reads/writes ratio? And what can I do about it?
I have an Oracle system with ASM that doing writes in a 15 minute cycle, and it causes a lot of writes with CP reads. The oracle ASM luns are basically the only thing on the aggregate. Disk alignment is fine (which is the first thing I thought of). I've
attached a screenshot of the Oncommand graph for one of the disks in this aggr-- not sure if that will come through.
The filer is a 3220 with 8.1.2 7-mode. Fibre channel attach, and there are about 20 luns under two volumes.
TIA,
Fred
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