Wols Lists wrote:
> On 16/06/20 10:04, Dale wrote:
>> I might add, I don't have LVM on that drive.  I read it does not work
>> well with LVM, RAID etc as you say.  Most likely, that drive will always
>> be a external drive for backups or something.  If it ever finds itself
>> on the OS or /home, it'll be a last resort. 
> LVM it's probably fine with. Raid, MUCH less so. What you need to make
> sure does NOT happen is a lot of random writes. That might make deleting
> an lvm snapshot slightly painful ...
>
> But adding a SMR drive to an existing ZFS raid is a guarantee for pain.
> I don't know why, but "resilvering" causes a lot of random writes. I
> don't think md-raid behaves this way.
>
> But it's the very nature of raid that, as soon as something goes wrong
> and a drive needs replacing, everything is going to get hammered. And
> SMR drives don't take kindly to being hammered ... :-)
>
> Even in normal use, a SMR drive is going to cause grief if it's not
> handled carefully.
>
> Cheers,
> Wol

>From what I've read, I agree.  Basically, as some have posted in
different places, SMR drives are good when writing once and leaving it
alone.  Basically, about like a DVD-R.  From what I've read, let's say I
moved a lot of videos around, maybe moved the directory structure
around, which means a lot of data to move.  I think I'd risk just
putting a new file system on it and then backup everything from
scratch.  It may take a little longer given the amount of data but it
would be easier on the drive.  It would keep it from hammering as you
put it that drive to death. 

I've also read about the resilvering problems too.  I think LVM
snapshots and something about BTFS(sp?) has problems.  I've also read
that on windoze, it can cause a system to freeze while it is trying to
rewrite the moved data too.  It gets so slow, it actually makes the OS
not respond.  I suspect it could happen on Linux to if the conditions
are right.

I guess this is about saving money for the drive makers.  The part that
seems to really get under peoples skin tho, them putting those drives
out there without telling people that they made changes that affect
performance.  It's bad enough for people who use them where they work
well but the people that use RAID and such, it seems to bring them to
their knees at times.  I can't count the number of times I've read that
people support a class action lawsuit over shipping SMR without telling
anyone.  It could happen and I'm not sure it shouldn't.  People using
RAID and such, especially in some systems, they need performance not
drives that beat themselves to death.

My plan, avoid SMR if at all possible.  Right now, I just don't need the
headaches.  The one I got, I'm lucky it works OK, even if it does bump
around for quite a while after backups are done. 

My new to me hard drive is still testing.  Got a few more hours left
yet.  Then I'll run some more tests.  It seems to be OK tho. 

Dale

:-)  :-) 

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