SUMMARY: large LUNs & labels & inodes (plus additional info)

Dear All,

I've got to answers - thanks to Drew Skinner & Mark Day .
Query & answers are attached at the end.

Seems the trick given by Mark should work. However I 
went other way. I did not changed EFI labelling on temporary space
(I'm copying out data from large array in order to replace all disks 
onto temporary space [which is loan array]). But I was more carefull 
creating new luns on my reinstalled array - simply  created more smaller 
luns on array side - all were below some 500GB and it seems this is
safe limit (I had to play little with setting of number of heads and 
cylinders in array) in order to be free in setting fragment size and 
inode size.

Anyway I'm really very disappointed with the fack that for filesystems
(ufs) larger than 1TBytes the inode size must be larger or equal 1Mbytes.
>From my side this makes use of multiterabyte filesystems impractical ...

Few additional notes from copying data:
(note: for Solaris 9 SPARC, after applying patch cluster dated Apr/8/2005
uname -a = SunOS xyz  5.9 Generic_118558-05 sun4u sparc SUNW,Sun-Fire-V440 )

1) cp -rp  does not copy bad symlinks

2) /usr/sbin/tar  - silently ignores (skips) files larger than 8GBytes

I found a patch for last "feature" - 115336-03 (it's free patch) -
which fixes it. Anyone using routinely tar on Solaris 9 machine should
apply this patch (patch is dated Oct/25/2004)

3) /usr/sbin/tar has rarely used option "E" which states for Extended
headers. At first look it changes granulity of access time saved in an
archive, but this option is crutial for files larger than 8GBytes.

Best Regards,

Gb


============================= QUERY =================================
Dear All,

I have the following quite urgent query (I have to start
copying large amount of data immediatelly)  ...

I've got large SCSI array - some 3TBytes.
First I logged to the array and created  2 LUNs - 1.5TB each
(i.e. > 1TB ) and tried to label them with format. The partitions
looked different from "normal old style solaris" ufs partitions -
the first partition (0) started from 34th block and also there were 
partition number 8 called "reserved". I tried to modify them
and I could not start from first block or delete this
"reserved" 8th partition. Finally I gave up and created
partition #6 containing all available blocks. Googling I
learned that for devices > 1TB solaris makes EFI labels.

Then I tried to make ufs filesystem, but I found out
that for filesystems > 1TB the minimal number of bytes per inode
can be 1 Mbytes (i.e mkfs -i 1048576  ... ). Because I have
huge numeber of small file (some 50 milions of files from 1kBytes
to 100Kbytes) that was not an option for me.

So I logged to the array again and created 4 LUNs - 750GB each (i.e < 1TB).
Then I labaled disks (LUNs) again. But that was strange: LUNs # 0 and 2
preserved somehow EFI labels and LUNs # 1 and 3 got old style labels.
I tried to change the labels with format but I could not either
force all EFI or all old style labels. Finnaly I gave up again.

Interesingly when I tried to make filesystems on the LUNs,
I got  unexpected results. For EFI labeled LUNs I could
make "-i 8192" i.e. 8KBytes per inode, but for old style labeled
LUNs I could not make less than 12KBytes per inode (i.e. -i 12000 -
option for mkfs)..

So my question is if there is any tool or way to switch between
"old style" and EFI labels for LUNs smaller than 1TB ???
And other question: may  this labeling  influence on filesystem performance ???

I tried to learn more on sunsolve but most of documents were protected
(usually they were not) ...

THanks for any help.

Kind regards,

Gb

============================== ANSWER 1 ===============================
Drew Skinner <dskinner_at_blueprint.org>
Date: Thu, 07 Apr 2005 14:00:18 -0400

Hi;

I've had exactly the same problem with T3's that were configured with
180GB disks. A 'complete' T3 would present itself as 1.2T which
generated the EFI labels. As I didn't want that, I ended up having to
destroy the LUNs on the T3's and recreate them. The trick I used to
accomplish this was by turning on/off MPXIO on the Solaris host so as to
alter the WWN's being presented back.

I also found them to be persistent (and nasty to get rid of). I didn't
see (or find) any tools to help here and I'm sure using MPXIO in this
manner is unsupported :)

-Drew
============================ ANSWER 2 =================================
Mark Day <Mark.Day_at_mrsc.ucsf.edu>
Date: Thu, 7 Apr 2005 11:00:36 -0700 (PDT)
My notes from when I ran into a similar problem say:

format -e will prompt for label type when labeling a disk that
is incorrectly getting EFI automatically.

Also you can use something like:
# prtvtoc /dev/rdsk/cztydxs2 > /tmp/vtoc
# fmthard -s /tmp/vtoc /dev/rdsk/cxtydzs2

To copy the label from a LUN with identical geometry to another LUN.


Mark Day
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