I noted
last month that a new OpenMPE Board had been seated and was busily working to
advance the goals of the OpenMPE community. By now you should have seen a
letter on the OpenMPE list from the Board indicating how we have decided to
handle HP’s confidentiality requirements, a controversial topic in the election
campaign. This will hopefully be the first of many regular reports to the
membership. The next year is going to be a critical one for OpenMPE. We need to
energize the MPE-IMAGE community and set up a funding stream. Supporting
OpenMPE is the best shot you have for MPE-IMAGE to exist post 2006 in some
supportable and maintainable form. Hopefully you are already a member. If not a
member, why not? Membership is still free. If you have not joined OpenMPE and
are not planning to, contact me. Give me a chance to talk you into changing
your mind.
Again in
May we had many off-topic political and religious threads on HP3000-L, but in
general the total number of off-topic posts was down comparatively. In fact,
the total number of OT postings for May was down considerably. One wag even
pointed out we went over 24 hours during the middle of one week without a
single off-topic posting! Perhaps the chief OT posters (you know who you are) are
finally getting tired? We can only hope.
I
always like to hear from readers of net.digest and Hidden Value.
Even negative comments are welcome. If you think I’m full of it or goofed, or a
horse's behind, let me know. If something from these columns helped you, let me
know. If you’ve got an idea for something you think I missed, let me know. If
you spot something on HP3000-L and would like someone to elaborate on what was
discussed, let me know. Are you seeing a pattern here? You can reach me at
john@burke-consulting.com.
Homesteaders
take note. Get rid of that internal DDS tape drive.
Several
people complained recently of problems with internal DDS tape drives in systems
located in remote areas with little onsite expertise, problems that led to
frequent drive replacements and downtime. It reminds me of the old vaudeville
joke where the patient comes to the doctor with a complaint, “Doc, it hurts
when I do this.” The doctor replies, “Then don’t do that.”
HP 3000
gurus have been cautioning for years that people should not use internal tape
or disk drives in 9x7, 9x8 or 9x9 production systems. The most likely failure
is a tape drive and the next most likely failure is a disk drive. Everything
else in the system cabinet could easily run for a decade without needing
service or replacing. When an internal tape or disk drive fails you are looking
at serious downtime while the case is opened and the drive is replaced. A
common urban legend says that the primary boot device (LDEV 1) and the
secondary boot device (usually LDEV 7) must be internal. Not true.
Bite the
bullet now. Remove, or at least disconnect (both power and data cables) all
internal drives. Replace the internal DDS drive with an external DDS3 or DDS4
drive. In the case of the DDS drive, you will not even need to make any
configuration changes if you set the SCSI ID to 0 on the external drive.
Usually, the internal DDS drive is at SCSI ID 0 (for a 9x7, this is 52.0.0; for
a 9x8, this is 56/52.0.0; and, for a 9x9, it is something like 10/4/20.0.0). If
you do not want to open the case even to disconnect the drives, you can
probably set the SCSI ID on the external DDS drive to 1 since this is usually
not used. On 9x9s, SCSI ID 2 is used for the CD-ROM. Disk drive addresses will
vary with the system, but even if you replace the internal disk drives with
external JBOD, you are still ahead of the game. Remember, if you have to change
SCSI IDs, you will have to change your SYSGEN configuration and your boot
device paths.
Someone
also asked whether if you changed the boot path you should immediately create a
new SLT. Technically, the answer is no since the SLT contains no information
about boot paths. However, if you have not created an SLT since the device was
added (and why not?), then by all means create a new SLT. It should also be
noted that DDS drives are notorious for not being able to read tapes created on
other DDS drives. So, if you do not think you have time to create a new SLT, at
least use CHECKSLT to verify you can read your existing SLT on your new drive.
If you cannot read your existing SLT, then MAKE TIME to create a new SLT. Your
standard procedures should include regularly creating and SLT and checking it.
Take it from someone with over 25 years of IT management experience, if
anything can go wrong, it will, and at the most inconvenient time. So protect
yourself and your organization’s IT.
So, what do all
those abbreviations that LISTF(ILE) spits out mean?
Every now and then I run across some LISTF or LISTFILE
output that I do not recognize. Usually I can figure out what the abbreviations
mean because I know something about the file. But I do not remember coming
across in one place a description of all the abbreviations. Not surprising
really since a number of different abbreviations have been added over time as
new file types have been added. This month someone ask about a couple in
particular which started people off on their own trips down memory lane.
Finally, Jeff Vance gave what is undoubtedly the definitive list, reproduced
here:
SIZE field
==========
Column 1 (after numeric record width):
if file is ASCII then 'B'
else 'W' and divide recsize by
2
Column 2:
if file has been migrated
then 'm'
elseif file is compressed
then 'c'
else ' ' (space)
TYP field
=========
Column 1:
---------
FIXED 'F';
VARIABLE 'V';
UNDEFINED 'U';
ACCT00 'R'; ## root
GROUP00 'A'; ## MPE account
FILESET00 'G'; ## MPE group
BYTE_STREAM 'B';
HPDIR00 'H'; ## HFS directory
Column 2:
---------
if ASCII then 'A'
else 'B'
Column 3:
---------
if CCTL then 'C'
Column 3 or 4 (depending on CCTL or not):
-------------
if ORDINARY file and
device_type = STREAMS then 's'
elseif RIO then 'R'
elseif NMKSAM then 'K'
elseif CIRCULAR then 'O'
elseif SPOOL then 'S'
elseif MESSAGE then 'M'
elseif KSAM_64 then 'k'
elseif DIR_OBJ then 'D'
elseif FIFO then 'f'
elseif SYMLINK then 'L'
elseif DEVICE_LINK or
TTY_DEV_LINK 'd'
Google is your best friend when looking for information
about MPE.
There are many MPE/iX features/enhancements/procedures that
are only informally “documented” if at all. Frequently this “documentation”
appears on forums such as HP3000-L, etc. The various LISTF(ILE) abbreviations
above are one recent example. Another example that came up this month is
NSSWITCH. A poster said, “Wouldn’t it be nice if MPE/iX supported NSSWITCH?” I
do not know if he checked docs.hp.com, but I did, and got no hits for NSSWITCH
and MPE. Of course I already knew the enhancement had been announced and
discussed several years ago on HP3000-L, so I advised him to check the HP3000-L
archives. Jeff Kell, who through the University of Tennessee at Chattanooga
sponsors and maintains HP3000-L, suggested using Google instead of HP3000-L’s
(raven’s) search engine. Not only is it faster (raven’s search is single
threaded) but it obviously covers more territory, though Jeff pointed out
Google does not seem to index every HP3000-L posting. I tried Google and, sure
enough, it brought up links to the HP3000-L postings in an instant. It also
brought up links to the Hidden Value columns where I consolidated information
about NSSWITCH. Duh!
Accounting structure and user volumes, or, “Why
can’t I add this group?”
This is another one of those things that seems to have
slipped through the cracks for many system managers. The group is the basic
file container for MPE/iX. As long as you only have one volume set,
MPEXL_SYSTEM_VOLUME_SET, the whole process of managing accounts and groups is
relatively straightforward. The confusion comes in when you add one or more
user volumes. The primary accounting structure for groups is housed in the
MPEXL_SYSTEM_VOLUME_SET directory. However, for a group residing on a user
volume set, some directory information also resides on the user volume set. In
this case, you have to add (or delete) a group twice, once for the system
volume set directory and once for the user volume set directory. If you do not
follow this procedure, you can end up with directory group fragments on your
user volume sets, as the poster to HP3000-L did. He was unable to add a new
group because the group already existed in the user volume set directory.
This is one feature of MPE/iX that is well documented, in
this case in the “Volume Management” manual
(http://docs.hp.com/mpeix/pdf/32650-90491.pdf). Several years ago, Jeff Vance
put together a set of UDCs to replace the MPE/iX NEWGROUP, etc. commands so
that you do not have to remember to do the NEWGROUP and PURGEGROUP commands
twice. Many users have found these UDCs quite helpful and have made them a part
of their regular system administration toolkit. The UDCs are available on the
jazz server.
STORE-to-disk, another poorly understood and
underutilized feature.
STORE-to-Disk (StD) is one of those really useful product
features that most people have, but that many people are unaware they have.
Even some people who know they have it are unaware of its power. This feature
allows you to treat a disk file the same as a tape drive, storing information
to disk in the same format, and with most of the same options, available when
storing to tape. It came up in two different contexts this month. Originally,
STORE-to-disk was not part of FOS STORE, but was only delivered with the extra
cost TurboSTORE II. However, it was made part of FOS STORE during the MPE/iX
6.5 time frame with patches available to add it to MPE/iX 6.0 systems. One of
the key attributes of StD is it gives you the ability to move files either
within a system or between systems without the use of external media, all the
while maintaining all the file information, including timestamps. On a single
system, it give you an easy way to move file sets to different groups, or even
the same group on a different volume set, without resorting to tape or changing
any file characteristics. For different systems, you package your files
together as one big file, ftp it to the other system, and then RESTORE the
files from the package. This is how the HP Response Center has handled patches
now for several years. Another way to use StD is to have a JBOD volume set
dedicated to backups. Instead of storing directly to tape, you do your backups
to disk (much faster), and then copy them to tape when convenient. In addition
to cutting down on downtime, this makes unattended backups much less risky.