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Re: Homebuilt NAS Advice

From Leslie Rhorer <lesrhorer@att.net>
Newsgroups linux.debian.user
Subject Re: Homebuilt NAS Advice
Date 2020-08-07 09:10 +0200
Message-ID <AB4FP-4ki-9@gated-at.bofh.it> (permalink)
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On 8/6/2020 11:08 AM, Stefan Monnier wrote:
>> 	For better performance, more space, and higher throughput, I would
>> 	probably create a RAID 4 or RAID 6 array from the external enclosure
>> 	and use it as the data repository.
> 
> And you suggest I put a 4-drive enclosure in my backpack next to my laptop?
> Seriously?

	Yes.  Also a bottle of water and a pocket knife.

>>> For the BananaPi, the suggestion is marginally less problematic but
>>> still: a non-trivial constraint with significant immediate downsides.
>> 	Such as?
> 
> Extra space taken, extra power used 24/7 (which in turn requires an
> extra plug because the poor BananaPi can't provide all that power),

	Now it is my turn to ask, "Seriously?"

> extra costs (the single drive I use was itself more than 3/4 the price
> of the whole system, so adding a second drive (complete with external
> power supply and enclosure) would double the price of the system),

	The Banana Pi is indeed extremely economical.  I have ten of them, plus 
17 Raspberry Pi 3B computers.

> Extra failures (more hardware => more failures), ...

	More failures on average, but far less serious and costly ones.


>>> RAID is basically an insurance.
>> 	Not entirely.  A RAID 5 or RAID 6 array is far, far faster than
>> 	a single hard drive.
> 
> Right, RAID-over-USB is of course going to blow my SSD-over-SATA out of
> the water by a wide margin (not!).

	On the Banana Pi it can.  On the laptop, probably not, assuming as you 
say, an SSD.

>> 	It is also much larger than a single hard drive, sometimes at
>> 	less expense than a single large hard drive.
> 
> That's great if you happen to be in that spot, but that's not my case.

	What spot?  You mentioned cost.  For many configurations, 4 small 
drives are cheaper than 1 large one.


>> 	It is also portable from one system to another.  Unplug the array
>> 	from the laptop, plug it in to the Banana Pi, and presto! The array
>> 	is now attached to the Pi.
> 
> Wonderful.  But then it's not a RAID shared with the internal drive
> any more.  So it won't protect my root partition.

	It can, but I probably would not.  Assuimng / is, say, 20G or so, one 
can create a loop device on the array of the same size and make the 
internal drive and the loop device a RAID 1 mirror.  If the main drive 
fails, install a new drive, partition it, boot from a thumb drive, make 
the new partition a mirror of the eternal file.  Go away for an hour or two.

	The same can be done making a partition on the external drives instead 
of a loop device, but it is a little less flexible.

> And if I keep my home
> partition in it, the "presto" comes with the footnote "after you logout
> and log back in" (fun!)

	You lost me.  Why log out?

> but if I don't keep my home partition on it,
> then my home partition is again not protects by RAID at which point I'm
> starting to wonder what I would put on that RAID.

	Data, but then I definitely recommend putting /home on the external 
array, so the question is a bit moot.

>> 	It's really not any different logically than an external drive,
>> 	except it is faster, larger, and more robust.
> 
> It's no different, indeed, except a bit more expensive and bigger.

	Well, OK.  How much is down-time worth?  If you consider the cost of 
the downtime associated with a failed system to be trivial, then that 
aspect is not important.

> But more importantly: there's a reason why I'm not using an external
> drive at all in the first place.

	I am sure there is.  Do you admit that external drives are extremely 
popular?  Literally millions of them are sold every year.

> If a disk dies in the RAID, you still have to replace it

	Well, one should.  It's not required, and there have been cases where I 
could not replace a failed drive for several days.

> and the
> performance is affected for a while.  The cost is never
> completely eliminated.

	It is affected during the rebuild, not the time between the failure and 
replacing the drive.  One can manage the amount of impact, however, and 
one can always delay the rebuild until off hours.


>>> anyway (not to mention that RAID doesn't prevent me from losing work
>>> when the OS or my editor crashes
>> 	Uh, yeah, it can.  It definitely can be used to eliminate data loss
>> 	when the OS crashes,
> 
> Of course it can't: when the OS crashes, the unsaved work in your editor
> is lost.

	Yes, of course.  I mistook what you were saying.  Are you suggesting 
that is not the case for a non-RAID system, however?

>> 	That is another matter.  Indeed, it is probably the most likely
>> 	reason a need for a backup solution exists.
> 
> For my use-case, RAID would cost a fair bit of money and inconvenience,
> and the benefit would be rare and minor.

	How much does downtime and time to rebuild a system cost you?  For many 
of us, even an hour of downtime is very expensive, and rebuilding a 
machine during peak hours can be hideously costly.  It is always a pain 
in the ass.

> I suspect your "world" is one where you have U1 blades and things like

	No.  My servers and workstations are relatively inexpensive desktop 
class clones.

> that and/or where the disk's content is not 100% your own (i.e. other
> people depend on it)

	Not exactly.  It's not the content upo which people rely, per se, but 
the ability of the systems to remain online.  More importantly in my 
case, *I* rely on the systems to be up continuously.  Downtime can be 
very expensive for me.  Certainly more than the cost of a hard drive.

> so for your use case RAID is probably
> a no-brainer.  For me, the choice is similarly blindingly obvious but
> diametrically opposed because my use case is radically different.

	Perhaps so.  How many people - especially Debian users - consider a 
catastrophic failure to be cost-less?  Debian's paradigm is based upon 
being rock solid and stable.  Ubuntu gives up stability for the sake of 
new bells and whistles.  I expect the typical Debian user is concerned 
about things like downtime and reliability.  You seem not to be.  If you 
are aware of and willing to take the risk, then that is fine.  I 
certainly am not, and as a responsible professional I certainly would 
not ever recommend it.  If anyone loses something based on my 
recommendation, they are very likely to come back and scream at me.  I 
really don't care for that to happen.

	Safety at all levels is always my top consideration.  The second is 
safety, followed by safety.  After that, it is speed, efficiency, and 
cost, in that order, unless they impact safety.  One could consider me 
obsessive, I suppose, but I cannot count the number of times being 
exceedingly cautious has saved my butt, and even my life. 
Unfortunately, I also cannot count the number of times not being quite 
cautious enough has jumped up and bitten me hard in the butt.

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Thread

Homebuilt NAS Advice Patrick Bartek <patrick.bartek@gmail.com> - 2020-07-29 22:00 +0200
  Re: Homebuilt NAS Advice Dan Ritter <dsr@randomstring.org> - 2020-07-29 22:20 +0200
    Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-07-29 22:30 +0200
      Re: Homebuilt NAS Advice Dan Ritter <dsr@randomstring.org> - 2020-07-29 23:40 +0200
    Re: Homebuilt NAS Advice Patrick Bartek <patrick.bartek@gmail.com> - 2020-07-30 02:50 +0200
      Re: Homebuilt NAS Advice Tom Dial <tddial@comcast.net> - 2020-07-30 22:50 +0200
        Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-02 01:40 +0200
          Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-02 03:10 +0200
            Re: Homebuilt NAS Advice Keith Bainbridge <ke1th3216@gmail.com> - 2020-08-02 04:50 +0200
              Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-02 06:10 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-02 21:30 +0200
            Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-02 22:10 +0200
          Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-03 06:10 +0200
            Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-03 17:30 +0200
              Re: Homebuilt NAS Advice Dan Ritter <dsr@randomstring.org> - 2020-08-03 17:40 +0200
              Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-03 18:40 +0200
                Re: Homebuilt NAS Advice <tomas@tuxteam.de> - 2020-08-03 19:10 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-03 22:00 +0200
                Re: Homebuilt NAS Advice <tomas@tuxteam.de> - 2020-08-03 22:20 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-03 23:50 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-04 00:50 +0200
            Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-04 00:40 +0200
    Re: Homebuilt NAS Advice Anssi Saari <as@sci.fi> - 2020-07-30 10:00 +0200
      Re: Homebuilt NAS Advice rhkramer@gmail.com - 2020-07-30 13:20 +0200
  Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-07-30 01:50 +0200
    Re: Homebuilt NAS Advice Patrick Bartek <nemommxiv@gmail.com> - 2020-07-30 23:40 +0200
    Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-08 01:30 +0200
      Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-08 03:30 +0200
        Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-09 14:40 +0200
  Re: Homebuilt NAS Advice Peter Ehlert <peter@sdi-baja.com> - 2020-07-30 19:00 +0200
    Re: Homebuilt NAS Advice Charles Curley <charlescurley@charlescurley.com> - 2020-07-30 21:50 +0200
      Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-07-31 13:10 +0200
    Re: Homebuilt NAS Advice Patrick Bartek <nemommxiv@gmail.com> - 2020-07-30 23:30 +0200
      Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-02 01:50 +0200
        Re: Homebuilt NAS Advice Patrick Bartek <nemommxiv@gmail.com> - 2020-08-02 17:50 +0200
  Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-03 17:20 +0200
    Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-04 00:10 +0200
      Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-04 01:20 +0200
        Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-04 10:40 +0200
          Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-04 11:30 +0200
            Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-08-04 16:00 +0200
              Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-04 16:30 +0200
              Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-05 05:50 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-05 16:20 +0200
                Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-05 17:00 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-05 17:40 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-06 12:10 +0200
                Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-08-06 16:10 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-06 17:10 +0200
                Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-08-06 18:10 +0200
                Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-07 18:30 +0200
                Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-08-07 19:40 +0200
                Re: Homebuilt NAS Advice rhkramer@gmail.com - 2020-08-08 00:10 +0200
                Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-08-09 04:30 +0200
                Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-09 11:10 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-09 17:00 +0200
                Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-08-09 18:30 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-09 19:20 +0200
                Re: Homebuilt NAS Advice rhkramer@gmail.com - 2020-08-09 23:50 +0200
                Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-08-10 00:00 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-10 00:30 +0200
                Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-10 00:50 +0200
                Re: Homebuilt NAS Advice rhkramer@gmail.com - 2020-08-10 00:30 +0200
                Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-10 00:30 +0200
                Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-08-09 18:40 +0200
                Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-09 23:00 +0200
                Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-06 18:20 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-07 05:30 +0200
                Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-07 18:30 +0200
                Re: Homebuilt NAS Advice rhkramer@gmail.com - 2020-08-06 17:20 +0200
                Re: Homebuilt NAS Advice Celejar <celejar@gmail.com> - 2020-08-06 18:20 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-06 18:20 +0200
        Re: Homebuilt NAS Advice Andrei POPESCU <andreimpopescu@gmail.com> - 2020-08-04 17:20 +0200
          Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-05 06:20 +0200
        Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-05 04:30 +0200
          Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-05 09:20 +0200
            Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-05 11:00 +0200
              Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-05 21:00 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-06 03:50 +0200
                Re: Homebuilt NAS Advice Kushal Kumaran <kushal@locationd.net> - 2020-08-06 06:20 +0200
                Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-06 18:20 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-07 04:10 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-07 05:50 +0200
            Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-05 12:30 +0200
      Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-05 12:30 +0200
        Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-05 21:10 +0200
          Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-05 23:30 +0200
            Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-06 00:30 +0200
              Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-06 01:20 +0200
                Re: Homebuilt NAS Advice Jonathan Dowland <jon+debian-user@dow.land> - 2020-08-08 09:10 +0200
              Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-06 04:30 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-06 04:50 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-06 06:20 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-06 07:10 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-06 07:30 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-06 18:10 +0200
                Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-06 18:30 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-07 03:00 +0200
                Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-07 03:20 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-07 05:00 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-07 05:40 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-07 08:00 +0200
                Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-07 08:50 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-07 09:10 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-07 17:50 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-08 01:40 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-08 04:50 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-08 22:30 +0200
                Re: Homebuilt NAS Advice Stefan Monnier <monnier@iro.umontreal.ca> - 2020-08-09 00:20 +0200
                Re: Homebuilt NAS Advice deloptes <deloptes@gmail.com> - 2020-08-09 01:30 +0200
                Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-09 22:40 +0200
                Re: Homebuilt NAS Advice David Christensen <dpchrist@holgerdanske.com> - 2020-08-10 00:30 +0200
                Re: Homebuilt NAS Advice Leslie Rhorer <lesrhorer@att.net> - 2020-08-10 01:30 +0200
    Re: Homebuilt NAS Advice Patrick Bartek <nemommxiv@gmail.com> - 2020-08-04 06:30 +0200

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