Re: Apparently spurious ZFS CRC errors (was Re: ZFS data error without reasons)

From: Mark Powell <M.S.Powell_at_salford.ac.uk>
Date: Thu, 26 Mar 2009 08:56:20 +0000 (GMT)
On Wed, 25 Mar 2009, Bernd Walter wrote:

> WC is on, prefetch is off, but only because it had bad performance with
> MySQL.
> Drives are <WDC WD3200AAKS-00SBA0/12.01B01> Serial ATA II

Hmmm. Strange. My previous array was primarily WD5000AAKS, but I didn't 
have these issues with those.
   I actually had 6xWD5000AAKS and 6 more old drives (200GB, 3x250GB, 320GB 
& 400GB) joined together with gstripe and gconcat to make 3x500GB, for a 
total 9x500GB RAIDZ2. With some pretty old PATA Maxtor 200GB and 250GB in 
there; spread across ICH9, JMB363 and Sil3132; I'd've expected CRC issues 
then. I scrubbed my pool every week for 18 months or so, with no errors to 
report.
   However, it's only since I got these 6xWD10EADS that problems have 
occurred. Perhaps the higher throughput of these drives is highlighting 
issues elsewhere?

> I don't know if it is with the drives, but other reasons are less
> likely in my opinion.
> The system is located in a data center and since I only get a few errors
> I decided to live with it and not to debug it further.

I've decided to split my drives in two pools; 5x500GB RAIDZ1 of WD5000AAKS 
and the 6x1TB RAIDZ2 of WD10EADS. I'll see if they perform differently. 
I'm using the defaults of WC on, with all ZFS options enabled.
   Cheers.

-- 
Mark Powell - UNIX System Administrator - The University of Salford
Information & Learning Services, Clifford Whitworth Building,
Salford University, Manchester, M5 4WT, UK.
Tel: +44 161 295 6843  Fax: +44 161 295 5888  www.pgp.com for PGP key
Received on Thu Mar 26 2009 - 07:56:24 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:39:45 UTC