[geeks] bah.

[Phil Stracchino]

Jonathan C. Patschke wrote:
> On Thu, 12 Mar 2009, Phil Stracchino wrote:
> 
>>> The geom stuff... it has burned me a lot.  The geom raid software will
>>> happily destroy all your data with no warning either from the programs
>>> or the man pages, and they frequently locked up FreeBSD 6 and 7.  I
>>> have not tried FreeBSD 7.1 yet so things may have improved in that
>>> release.
>> Huh.  I used the recommended geom method for boot disk mirroring ...
>> wonder if that was part of the problem?  And considering it was
>> mirroring SATA disks, that sounds like a possible double whammy.
> 
> Knocking on wood, I have one system that has a pair of geom-mirrored
> disks, has seen constant (sometimes very heavy) disk and network activity
> since it was turned on 696 days ago, and has absolutely never gone
> unavailable.

Actually, my "most probable cause" theory about the stability issues is
that the 3Ware board is shaky.  System stable under light load, start
hitting the array hard [say, start copying a third of a terabyte of data
to it] and the machine falls over ... I'd suspect the disk controller,
wouldn't you?

Oh, for a nice pair of LSIs....

In the meantime, once I can get the BIOS flashed to v1.08 I'll be trying
the FreeBSD route again and see if it'll boot amd64 then.


> Let me qualify my praise of geom with a stern damning stemming from its
> needlessly spartan documentation and overall lack of discoverability.  If
> you don't know that it's there (and up until FreeBSD 7 or so, you wouldn't
> know unless you asked someone who knew), you won't stumble across it.
> And, even if you do stumble across it, the handbook and man pages don't go
> into a lot of depth.
> 
> For example, the gjournal manpage nowhere tells you that if you have
> enough I/O activity to overrun the journal, your box will panic.  That's
> the sort of things folks might want to know, just perhaps.


Huh.  Yeah, that'd be an important thing to know ....  but that
shouldn't be relevant to heavy I/O activity on the storage array managed
by ZFS, not on the boot pair managed by geom, should it?


-- 
  Phil Stracchino, CDK#2     DoD#299792458     ICBM: 43.5607, -71.355
  alaric at caerllewys.net   alaric at metrocast.net   phil at co.ordinate.org
         Renaissance Man, Unix ronin, Perl hacker, Free Stater
                 It's not the years, it's the mileage.