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

[Morgan Wesström]

Jeremy Chadwick wrote:
> No offence intended by this statement, but: the Green drives are
> specifically intended for workstations.  I don't believe in the whole
> "segregation of drive model" thing, but the fact of the matter is, the
> Green drives are variable-RPM and have numerous firmware-level features
> which intend for them to be used in workstation environments -- that
> means not constant I/O or heavy workload.  Windows has nothing to do
> with this.

No offence taken. You are one of the few highly regarded contributors to
this list and I always appreciate the information you share.
My comment about Windows was based on the fact that Windows-users don't
experience this behaviour. The 8 second Intelli-Park timeout is most
probably tuned to the Windows kernel flush period but I can't say for
sure. But obviously the load/unload cycle isn't triggered nearly as
often on that OS. I just feel frustrated that once again a manufacturer
simply ignore the users who chose to run something else on their
computers than the products from Redmond.
In my case I have several decades worth of experience and knowledge and
I have no problem grasping the various technical features and their
usefullness. The problem is that I as a consumer have no way of knowing
that a feature like this would be incompatible in my environment despite
my experience. In my search to track this problem down I sidetracked
several times in both filesystem and kernel internals until I finally
stumbled over the Intelli-Park feature. It hadn't even crossed my mind
that the problem could be related to a hardware feature and that bothers
me immensely... but I'll deal with it eventually ;)

> Aren't Samsung's drives known for firmware bugs/quirks?  The
> documentation associated with smartmontools discusses this quite a bit.
> This is one reason why I stay away from them.  Fujitsu is another vendor
> I want absolutely nothing to do with (very high failure rates in
> addition to bad sectors with their SCSI-3 disks at my workplace).

I think both you and I know by now that every harddrive manufacturer
have their problems with certain models at some point. What surprises me
is the total lack of understanding from the manufacturers, most recently
the firmware issue of Seagates 7200.11 series where they simply try to
ignore the problem. The only professional response I've seen during my
career is IBM's replacement of their "Deathstar" drives many years ago.
I accept and understand that a manufacturer now and then makes a bad
product but it's how they deal with the situation when it occurs, that
decides whether I will ever buy their products again. With Samsung I've
completed the full circle and if I run into a problem with them and they
don't take their responsibility, well, then I'm not sure what to buy
next time. Maybe I should go for Maxtor again... ;-)

Regards
Morgan