[OpenIndiana-discuss] sd.conf trouble and illumos bug #3220

Wed Jan 8 22:51:13 UTC 2014

I think a wiki update is in order.  As simple an idea as it is, it was not obvious to me to do that.
I'm sure this will come up again.

--------------------------------------------
On Wed, 1/8/14, Bryan N Iotti <ironsides.medvet at runbox.com> wrote:

 Subject: Re: [OpenIndiana-discuss] sd.conf trouble and illumos bug #3220
 To: openindiana-discuss at openindiana.org
 Date: Wednesday, January 8, 2014, 1:55 PM

 Adding a wildcard for the all devices
 to use the 4K block size did indeed work and drastically
 improved the performance (and, I guess, life expectancy) of
 that SSD.

 I also added "physical-block-size=512" entries for all
 traditional 512-byte block disks connected to this machine
 and they are running fine.

 The scrub speed on the SSD (only quick test I could think of
 to try sustained read and write) went from 160MB/sec to
 250MB/sec. If I use 8K it doesn't change as much, but seems
 to be more constant. System has been running for a couple of
 hours and it's nice and snappy.

 Should I add a line to the OI wiki about the wildcard
 options? I didn't see them there last time I looked and they
 can be handy for newcomers and the like.

 Bryan

 On Mon, 6 Jan 2014 12:49:53 -0800 (PST)
 Reginald Beardsley <pulaskite at yahoo.com>
 wrote:

 > Sadly yahoo mail makes a mess of replies embedded in
 the text :-(
 > 
 > I'll have to try the 3 TB USB drive again.  I
 certainly can't see any reason that your wildcarding scheme
 shouldn't work.  If there is a problem it's probably a
 bug.
 > 
 > There are so many lies being told about geometry that
 it's hard to say what you should do.  At one point I
 wound up with a partition that was not 4k aligned if I
 started with cylinder #1, so I used #2 which was 4k
 aligned.  However, the 2k aligned partition seemed to
 work OK, so I'm not certain.  I wasn't willing to leave
 it that way to avoid wasting a little space.
 > 
 > I can't think of any reason that 512B drives wouldn't
 work fine aligned to larger boundaries.   The
 only consequence I can see is some wasted space which really
 isn't an issue given we're talking pennies per GB.  I
 can't imagine a performance issue that could result.
 > 
 > It seems to me that the default alignment rules would
 give less trouble if the alignment was to the most
 restrictive requirement.
 > 
 > --------------------------------------------
 > On Mon, 1/6/14, Bryan N Iotti <ironsides.medvet at runbox.com>
 wrote:
 > 
 >  Subject: Re: [OpenIndiana-discuss] sd.conf
 trouble and illumos bug #3220
 >  To: openindiana-discuss at openindiana.org
 >  Date: Monday, January 6, 2014, 12:08 PM
 >  
 >  Hi Reginald,
 >  
 >  Thanks for your reply.
 >  
 >  In the end, I just booted from a live DVD and
 plugged that
 >  drive in on my laptop using a double asterisk as
 the sd.conf
 >  line and an 8k block size. A test pool create
 read back
 >  ashift=13, which should be fine.
 >  
 >  Then I used format -e and fdisk to create a
 single Solaris
 >  slice with start and end blocks that would fall
 on a
 >  cylinder number that was divisible by 8 (I did it
 like for
 >  4K disks, if I'm wrong I'd like some input on
 that please).
 >  
 >  Then I created the rpool in the first slice and
 moved the
 >  disk over to the final system, where I sent and
 received the
 >  zfs datasets. Change menu.lst, install grub and I
 was done.
 >  Working fine so far (160MB/sec sustained on a
 scrub, normal
 >  wsvc_time and asvc_time in iostat).
 >  
 >  Would anyone see any problem in doing the sd.conf
 line
 >  backwards, I mean masking all drives as "**" with
 a 4K
 >  blocksize and adding entries for the other
 512-byte drives?
 >  What would happen if ZFS thought a 512-byte block
 device
 >  used a 4K block size? Wasted space, performance
 issue,
 >  errors?
 >  
 >  Thanks, as always, for any and all input.
 >  
 >  
 >     Bryan
 >  
 >  
 >  On Sun, 5 Jan 2014 16:10:58 -0800 (PST)
 >  Reginald Beardsley <pulaskite at yahoo.com>
 >  wrote:
 >  
 >  > I can't comment on your particular issue
 which is why I
 >  didn't respond earlier.  However,  I had
 trouble
 >  getting a 3 TB Toshiba USB drive to work
 properly.  I
 >  spent a bunch of time reading the code that
 parses sd.conf,
 >  but finally gave up and didn't go further.
 >  > 
 >  > On reflection I wonder if the problem is a
 failure to
 >  propagate the information about block size to ZFS
 correctly
 >  under certain circumstances.  I think it would
 be nice
 >  if one could force ashift when creating a
 pool. 
 >  Automagic is nice, but there's often no
 substitute for human
 >  intelligence.  I spent a couple of days trying
 to
 >  persuade OI to create a properly aligned pool
 before I gave
 >  up.
 >  > 
 >  > 
 >  >  
 >  > 
 >  >
 _______________________________________________
 >  > OpenIndiana-discuss mailing list
 >  > OpenIndiana-discuss at openindiana.org
 >  > http://openindiana.org/mailman/listinfo/openindiana-discuss
 >  > 
 >  
 >  
 >  -- 
 >  Bryan N Iotti
 >  
 >  +39 366 3708436
 >  ironsides.medvet at runbox.com
 >  
 >  _______________________________________________
 >  OpenIndiana-discuss mailing list
 >  OpenIndiana-discuss at openindiana.org
 >  http://openindiana.org/mailman/listinfo/openindiana-discuss
 >  
 > 
 > _______________________________________________
 > OpenIndiana-discuss mailing list
 > OpenIndiana-discuss at openindiana.org
 > http://openindiana.org/mailman/listinfo/openindiana-discuss
 > 

 -- 
 Bryan N Iotti

 +39 366 3708436
 ironsides.medvet at runbox.com

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