immense delayed write to file system (ZFS and UFS2), performance issues

Jeremy Chadwick freebsd at
Tue Jan 19 11:24:51 UTC 2010

On Tue, Jan 19, 2010 at 11:07:24AM +0100, Gerrit Kühn wrote:
> On Tue, 19 Jan 2010 01:57:36 -0800 Jeremy Chadwick
> <freebsd at> wrote about Re: immense delayed write to file
> system (ZFS and UFS2), performance issues:
> JC> If you want a consumer-edition drive that's better tuned for server
> JC> work, you should really be looking at the WD Caviar Black series or
> JC> their RE/RE2 series.  
> That's exactly what I did. I have WD-RE2 drives here that show exactly
> this problem (RE2/GP)! The model number is WD1000FYPS-01ZKB0.

I should have been more specific.  WD makes RE-series drives which don't
have GP applied to them; those are what I was referring to.

Here's the current list of Western Digital SATA models out there, sans
some earlier revisions.  All below drives are 3.5", SATA300, and have
their SATA power/signal ports placed to permit hot-swapping in drive
carriers unless otherwise noted.

Enterprise high-performance class
WD3000GLFS - WD VelociRatpor, 300GB, 16MB, 10Krpm, no-hotswap
WD1500HLFS - WD VelociRaptor, 150GB, 16MB, 10Krpm
WD3000HLFS - WD VelociRaptor, 300GB, 16MB, 10Krpm
WD1500BLFS - WD VelociRaptor, 150GB, 16MB, 10Krpm, 2.5" bare
WD3000BLFS - WD VelociRaptor, 300GB, 16MB, 10Krpm, 2.5" bare

Enterprise business-critical class
WD2502ABYS - WD RE3, 250GB, 16MB, 7200rpm
WD3202ABYS - WD RE3, 320GB, 16MB, 7200rpm
WD5002ABYS - WD RE3, 500GB, 16MB, 7200rpm
WD1002FBYS - WD RE3,   1TB, 32MB, 7200rpm
WD7502ABYS - WD RE3, 750GB, 32MB, 7200rpm
WD2003FYYS - WD RE4,   2TB, 64MB, 7200rpm

Enterprise energy-saving class
WD5000ABPS - WD RE2-GP, 500GB, 16MB, variable rpm
WD7500AYPS - WD RE2-GP, 750GB, 16MB, variable rpm
WD1000FYPS - WD RE2-GP,   1TB, 16MB, variable rpm
WD2002FYPS - WD RE4-GP,   2TB, 64MB, variable rpm

Desktop class
WD800AAJS  - WD Caviar Blue,   80GB,  8MB, 7200rpm
WD1600AAJS - WD Caviar Blue,  160GB,  8MB, 7200rpm
WD2500AAJS - WD Caviar Blue,  250GB,  8MB, 7200rpm
WD3200AAJS - WD Caviar Blue,  320GB,  8MB, 7200rpm
WD2500AAKS - WD Caviar Blue,  250GB, 16MB, 7200rpm
WD3200AAKS - WD Caviar Blue,  320GB, 16MB, 7200rpm
WD5000AAKS - WD Caviar Blue,  500GB, 16MB, 7200rpm
WD6400AAKS - WD Caviar Blue,  640GB, 16MB, 7200rpm
WD5000AACS - WD Caviar Green, 500GB, 16MB, variable rpm
WD6400AACS - WD Caviar Green, 640GB, 16MB, variable rpm
WD7500AACS - WD Caviar Green, 750GB, 16MB, variable rpm
WD10EACS   - WD Caviar Green,   1TB, 16MB, variable rpm
WD5000AADS - WD Caviar Green, 500GB, 32MB, variable rpm
WD6400AADS - WD Caviar Green, 640GB, 32MB, variable rpm
WD7500AADS - WD Caviar Green, 750GB, 32MB, variable rpm
WD10EADS   - WD Caviar Green,   1TB, 32MB, variable rpm
WD15EADS   - WD Caviar Green, 1.5TB, 32MB, variable rpm
WD20EADS   - WD Caviar Green,   2TB, 32MB, variable rpm
WD6400AARS - WD Caviar Green, 640GB, 64MB, variable rpm
WD8000AARS - WD Caviar Green, 800GB, 64MB, variable rpm
WD10EARS   - WD Caviar Green,   1TB, 64MB, variable rpm
WD15EARS   - WD Caviar Green, 1.5TB, 64MB, variable rpm
WD20EARS   - WD Caviar Green,   2TB, 64MB, variable rpm
WD5001AALS - WD Caviar Black, 500GB, 32MB, 7200rpm
WD6401AALS - WD Caviar Black, 640GB, 32MB, 7200rpm
WD7501AALS - WD Caviar Black, 750GB, 32MB, 7200rpm
WD1001FALS - WD Caviar Black,   1TB, 32MB, 7200rpm
WD2001FAAS - WD Caviar Black,   2TB, 64MB, 7200rpm

So which drive models above are experiencing a continual increase in
SMART attribute 193 (Load Cycle Count)?  My guess is that some of the WD
Caviar Green models, and possibly all of the RE2-GP and RE4-GP models
are experiencing this problem.

I say "some" with regards to WD Caviar Green since I have some which do
not appear to exhibit the heads/actuator arm moved into the landing/park
zone.  I'm at work right now, but when I get home I can verify what
models I've used which didn't experience this problem, as well as what
the manufacturing date and F/W revisions are.  I should note I don't
have said Green drives in use (I use WD1001FALS drives now).

| Jeremy Chadwick                                   jdc at |
| Parodius Networking              |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |

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