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Re: zfs update

-----Original Message-----
From: Scott Duensing <scott@jaegertech.com>
Reply-to: silug-discuss@silug.org
To: silug-discuss <silug-discuss@silug.org>
Subject: Re: zfs update
Date: Sat, 19 Apr 2014 22:22:08 -0500

It took you a week to move 2.3T of data?  That sounds very wrong.  I have a similar setup here (10 x 4TB in RAIDZ2) and migrated my 9TB+ of data in just a couple days across GigE.

Scott,

I attribute at least part of the slowness of the first pass to the 4096:512 emulation which the ashift=12 parameter should have fixed on the return pass. There's something -- possibly inadequate caching memory space -- that ran up the load factor on the return pass to over 8 at one point. The pod has only 8GB and the smallest/slowest AMD 6000 series CPU. Another possibility is that the 1:5 SATA port expanders are inefficient.  The main server with a 2TB ZFS array has a proper server motherboard with dual quad-core 2000 series AMD CPUs and 32GB of ECC registered RAM.

--Doc