Hi all,
Thanks to you who offered your opinions and recommendations regarding our
proposed changes to the DSTAT command. Below we have summarized your input
and have offered a revised proposal. There are still a couple of questions
remaining, sprinkled throughout this posting.
[ There are 3 questions, did you see them? }
Objectives:
-----------
(1) Enhance DSTAT to handle up to 5 digit LDEV numbers and model numbers
greater than 7 characters. Long term we expect model numbers to be up to
28 characters long.
(2) Enhance DSTAT to show HAFO (High Availability Failover) information
for dual ported disks like the Nikes.
Feedback Summary:
-----------------
* It's OK to increase LDEV number and model number fields but don't
add any additional info to the default DSTAT output. Output will
continue to be in upper case. Specifically, it is ok to shift the
default output 1 or 2 characters to the right to accomodate 4 and 5
digit LDEV numbers. It is ok to increase the model field from 7 bytes
to a fixed size of 12 bytes. Note: today, DSTAT shifts one character
right for 4 digit LDEVs. Model numbers greater than 12 characters can
be silently truncated. Thus, the longest DSTAT line could look like:
today:
LDEV-TYPE STATUS VOLUME (VOLUME SET - GEN)
---------- -------- --------------------------
4-C3010M1 MEMBER MEMBER4 (MPEXL_SYSTEM_VOLUME_SET-0)
13-C3010M1 MEMBER MEMBER13 (MPEXL_SYSTEM_VOLUME_SET-0)
131-C2490AM MEMBER MEMBER131 (MPEXL_SYSTEM_VOLUME_SET-0)
1234-C23456 CP*MEMBER-MDMEMBER35 (MPEXL_SYSTEM_VOLUME_SET-0)
Proposal:
new Choice 1:
LDEV-TYPE STATUS VOLUME (VOLUME SET - GEN)
-------------- ------------ --------------------------------------------
4-C3010M1 MEMBER MEMBER4 (MPEXL_SYSTEM_VOLUME_SET-0)
13-C3010M1 MEMBER MEMBER13 (MPEXL_SYSTEM_VOLUME_SET-0)
131-C2490AM MEMBER MEMBER131 (MPEXL_SYSTEM_VOLUME_SET-0)
1234-C23456 CP*MEMBER-MD MEMBER35 (MPEXL_SYSTEM_VOLUME_SET-0)
12345-C23456789012 CP*MEMBER-MD MEMBER35 (MPEXL_SYSTEM_VOLUME_SET-0)
new Choice 2:
LDEV-TYPE STATUS VOLUME (VOLUME SET - GEN)
-------------- ------------ --------------------------------------------
4-C3010M1 MEMBER MEMBER4 (MPEXL_SYSTEM_VOLUME_SET-0)
13-C3010M1 MEMBER MEMBER13 (MPEXL_SYSTEM_VOLUME_SET-0)
131-C2490AM MEMBER MEMBER131 (MPEXL_SYSTEM_VOLUME_SET-0)
1234-C23456 CP*MEMBER-MD MEMBER35 (MPEXL_SYSTEM_VOLUME_SET-0)
12345-C23456789012 CP*MEMBER-MD MEMBER35 (MPEXL_SYSTEM_VOLUME_SET-0)
The difference between choices 1 and 2 are:
o choice 1 keeps the LDEV column aligned as it is today for all rows with
LDEVs three or less digits long. However, 4 digit LDEVs break this rule
today and 5 digit LDEVs will break it again tomorrow.
o choice 2 says bite the bullet and shift everything over to accomodate 5
digit LDEVs thus impacting the column location for all LDEVs not just those
that are 4 or more digits. Small shops with low LDEVs could be affected
by choice 2 and not by choice 1; however if we agree to increase the model
field to 12 bytes then we have potentially impacted everyone anyways.
>>> QUESTION <<<
Do you prefer Choice 1 as the new default for DSTAT, or choice 2?
VOTE:
___ Choice 1
___ Choice 2
___ Don't care
___ other
___ Don't change current output at all
* It is OK to abbreviate the STATUS field in the default case if we
don't have sufficient space to display bigger model names. However, today
the status field can contain 12 characters of data, as shown above. We
don't see an oppertunity to shorten the width of this field.
* Don't stagger the output of a single disk across multiple lines in
the default case.
* The default output will just truncate the model number if it's too
big and we will not display any character to indicate truncation.
* With the new DETAIL option, display HAFO info, disk size (in GB/MB ???)
and %free space of every volume (not volume set) also.
>>> QUESTION <<<
What should the units of measure be for the new disk capacity field?
VOTE:
___ megabytes (2^20)
___ gigabytes (2^30)
___ other
* Use lower case for the output in the new DETAIL format.
* Align the data for the output with DETAIL option so that everything
starts on the same column.
* Any field that doesn't have significance for a particular volume
should be left blank. Don't display NONE or NA etc.
Below are all of the fields and their max size (width) for the new
DSTAT FORMAT=detail output:
------------------------
LDEV: nnnnn (5)
MODEL: xxxxxxxxxxxxxxxxxxxxxxxx (24)
VOLNAME: xxxxxxxxxxxxxxxx (16)
VOLTYPE: xxxxxxxxxxxx (12)
VOLSET-GEN: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx-n (34)
DISK SIZE: xxxxGB (4) or xxxxxxxMB (7)
PRIMARY PATH: xxxxxxxxx (9)
PRIMARY STATUS: xxxxxxxx (8)
ALT PATH: xxxxxxxxx (9)
ALT STATUS: xxxxxxxx (8)
EVENT TIME: hh:mm:ss (8)
Important HAFO related fields
-----------------------------
PRIMARY PATH - path string for ldev
ALTERNATE PATH - alternate path (DAM path) to which I/O will be
rerouted for failover.
PRIMARY STATUS - status or operational readiness of primary path.
Status could be: array failure, failover failed, ready, test failover,
unknown failure, unknown status
ALTERNATE STATUS - status for alternate path. Status could be:array
failure, failover failed, ready, unknown failure, unknown status, not
validated
EVENT TIME - formatted date and time of failover event. Events will
be loged in the sysdiag file with additional time information.
The ALT PATH, ALT STATUS and EVENT line will be displayed only for
HAFO devices. These fields will be left blank for non-HAFO disks.
>>> QUESTION <<<<
or, should we just not display the ALT PATH, ALT STATUS and EVENT rows
if the device is not a HAFO device???
VOTE:
___ Always display the above three rows even if they don't apply to a
particular device (there will be no data after the label)
___ Don't display the rows/labels if they don't apply to a particular device
___ Don't care
___ other
Here's what it would look like for several devices -- some HAFO,
others not:
:dstat all;format=detail
LDEV: 31
MODEL: c2490am-nike
VOLNAME: member1
VOLTYPE: master
VOLSET-GEN: mpexl_system_volume_set-0
DISK SIZE (gb): 28.7
PRIMARY PATH: 8.0.0
PRIMARY STATUS: ready
ALT PATH: 16.0.0
ALT STATUS: ready
EVENT TIME:
LDEV: 32
MODEL: c2390am
VOLNAME: member2
VOLTYPE: member
VOLSET-GEN: mpexl_system_volume_set-0
DISK SIZE (mb): 28700
PRIMARY PATH: 8.0.1
PRIMARY STATUS: ready
ALT PATH:
ALT STATUS:
EVENT TIME:
LDEV: 31
MODEL: c2490am-nike
VOLNAME: member1
VOLTYPE: master
VOLSET-GEN: mpexl_system_volume_set-0
DISK SIZE (gb): 28.7
PRIMARY PATH: 9.0.0
PRIMARY STATUS: failover
ALT PATH: 17.0.0
ALT STATUS: ready
EVENT TIME: 09:09:09
------------------------------------------------------------
Thanks and regards,
Narayan, CSY
Jeff Vance, CSY
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