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Re: Need SAS HBA for Debian Jessie

On Monday, May 18, 2015 at 5:40:05 AM UTC-5, Petter Adsen wrote:

> >    I don't have money to send to Red Hat.  First of all, one reason
> > (although not the only one, by far) I am using Linux is it is free of
> > commercial restraints.  Secondly, these are not commercial systems.
> > These are a pair of home RAID arrays used primarily to store a
> > personal video library.  Thirdly, I rather dislike Red Hat's
> > distribution and administration system.  I much prefer Debian.
> I am sorry if this is a dumb question

   Not in the least.

> but if this is a home system,
> why can you not go for more commodity hardware? While I do recognize
> there are differences between SAS and SATA, do you really need SAS in
> a home setting - for a media library? SATA may be the simplest/cheapest
> solution, to my way of thinking.

   Not beyond about 10 drives, plus I have had a fair amount of problems with eSATA deployments.  The bottom line, however, is that in trouble shooting my problems with the systems I converted my 20 drive Port Multiplier eSATA chassis to multi-lane.

> I would assume there are far more people running Linux with a SATA
> system than there are for SAS, so it should be more widely tested, and
> information would not be so scarce. Granted, this might be less true
> when you are talking about high-end RAID controllers, but still.

   Oh, you're right, although I had many of the same issues in that area, as well.  That said, I still have not definitively pinpointed the source of the problems.  The LSI controller on the Squeeze system is working without a hard failure, however.  A couple of the drives still suffer timeouts with that controller, but it doesn't barf when they do.  It just resets the drive.  I would happily buy another of these LSI controllers, but they don't have support for the management utility under Jessie (or Wheezy, for that matter).  They work with the kernel, but without using the management software to tweak the controller parameters (especially the write-through cache), performance is truly dismal.  I mean really, really bad.

> Here I agree with you. OTOH, if this had been for a "enterprise"
> setting, a suggestion to check out RH - with their level of commercial
> support - would not necessarily be a bad one.

 Canonical might have been
> another one, I haven't personally dealt with them.
> > > to be very good at reliably supporting a lot of 
> > > different hardware. (I'm out of that consulting 
> > > biz now...for some time now.)
> > 
> >    Honestly, IMO this isn't primarily an issue of hardware support.
> > It is an issue of informational support by the hardware
> > manufacturers.  They post lots of fru-fru information about their
> > product without posting the information one really needs to know to
> > make an informed purchase.  Very few of the HBA manufactureer inform
> > the user whether the card at hand supports LBA 48 or not.  I have
> > purchase several controllers only to find the drive size limited to
> > 2T.  Many devices that only specify RH and / or SuSE are in fact
> > perfectly well supported under Debian and most of its derivatives.
> > Many just report Linux support, when in fact there is no support
> > under many distros.
> Again, I agree. In this scenario, I would find a couple of controllers
> that would seem to suit my purpose, and contact the manufacturers
> directly with very specific questions. One of these questions would be
> whether or not the controller is supported by the Linux kernel itself,
> or if it would require third-party software/modules to work, and if so,
> what systems those are available for.
> Since there are so many distributions that are based on Debian, and
> especially Canonical seems to have a little clout with manufacturers, I
> would suggest to them to investigate support for Debian-based systems.
> Not supporting it in this day and age would seem strange to me.
> > > There are many fates worse than becoming, for certain 
> > > of one's key systems, a RH customer. Even more so if 
> > > making money, or deliverables, is part of the job of 
> > > said key systems.
> > 
> >    It is not, and economy is definitely a key consideration, here.
> > What's more, I am not asking the OS to support any particular
> > hardware.  What I am asking - even if it were REd Hat - is whihc
> > hardware is supported.  That really should not be that difficult a
> > question.  (Yes, I understand why it is in fact a difficult question.)
> Yes, it is indeed a difficult question.
> This is just personal preference, but I would as far as possible avoid
> hardware that isn't supported by the Linux kernel itself, since that
> would leave me at the mercy of the manufacturer with regard to future
> support and updates.
> > > It boils down to the question "How much of my time do 
> > > I want to waste looking for those hens' teeth, and, 
> > 
> >   These aren't hen's teeth.  They are type O-Positive blood donors.
> > I just need the bag labeled with the blood type so I know which one
> > to choose.
> > 
> > > given what my time is worth, do I want to take that 
> > > hit?"
> > 
> >    As opposed to the huge amount of time it would take me to switch
> > operating systems?  Few, if any, of the dozens of scripts I have in
> > place to manage the system would work out of the box.  They would
> > need to be re-written.  Nearly all of the software I have written
> > would have to be re-compiled, and some might need to be re-written.
> > I would also have to spend a lot of time getting far more familiar
> > with Red Hat than I am now.  No, by far the most economical route is
> > just to buy HBAs that are compatible with the OS I have now.
> There really isn't much I can help you with, I'm afraid, other than to
> recommend you press the manufacturers of hardware that might suit your
> purposes to give you the information you need. If they aren't
> willing/able to tell a potential buyer what they need to know before
> purchase, I would stay far away. Also, you can ask them directly which
> of their products they would recommend you use. Get it in writing, if
> necessary.
> If you *do* find a controller that supports the features you need and
> is reported to work with Debian, I would ask here and do some searches
> to find out what experiences people have with that model specifically.
> Other than that, I can only wish you the best of luck :)
> Petter
> -- 
> "I'm ionized"
> "Are you sure?"
> "I'm positive."

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