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- Newsgroups: biz.sco.general
- Path: sparky!uunet!uunet.ca!xenitec!news
- From: news@xenitec.on.ca (xenitec.on.ca News Administrator)
- Subject: SCO Mailing List Technical FAQ
- Resent-From: mmdf@xenitec.on.ca
- Submit-To: scogen@xenitec.on.ca
- Organization: [resent by] The SCOGEN gateway and Propagation Society
- Date: Thu, 24 Dec 1992 03:01:10 GMT
- Message-ID: <1992Dec24.030110.16615@xenitec.on.ca>
- Precedence: bulk
- Lines: 355
-
- The SCO Mailing List/biz.sco.general Technical FAQ
- --------------------------------------------------
-
- Revision Information
- --------------------
- Version: 1.17
- Date: 30 November 1992 *** NO CHANGES SINCE LAST POSTING ***
- Author: Stephen M. Dunn
- stephen@bokonon.UUCP
- {uunet.ca,becker.gts.org,xrtll.UUCP}!bokonon!stephen
- New Features: Table of contents added; UUCP broken into own section;
- minor editing; added some contact information for
- compressed backup utilities
-
- NOTE: All lines that have been added or modified since the previous
- version are marked with ** at the start of the line.
-
- ****************************NEW SECTION BEGINS*****************************
- Table of Contents
- -----------------
- One Bit of Administrivia
-
- Questions and Answers Common to Unix, Xenix and ODT
- -How do I stop banners from printing?
- -Are there any screen savers?
- -How do I compress my backups?
- -My serial connections are losing characters
- -I don't like being restricted to 14 character filenames
- -How do I get a copy of adb?
- -I can't find crypt
-
- Questions and Answers Specific to Unix
- -I have a system memory dump in my swap space; how do I delete it?
- -How do I save kernel panic dumps to tape?
- -At boot time, the "Enter the root password or ^D" message doesn't work!
- -My Unix 3.2.0-3.2.2 machine gives errors on filenames greater than 14 chars
- -I just upgraded to 3.2v4 but I still can't use long filenames
- -The permissions on /usr/adm/sa and its children are wrong
-
- Questions and Answers about TCP/IP and NFS
- -telnet doesn't work properly
- -How do I know if I have enough streams buffers for TCP/IP and/or NFS?
- -TCP/IP gives messages like "Notice: TCP SUM: SRC 89270107 SUM 0000D7AD"
-
- Questions and Answers about UUCP
- -I can transfer small files via UUCP but large ones won't go
- -I can transfer small files via UUCP but large ones go really slowly
- -How do I change uucico's window size?
- -I increased my window size but nothing changed
- -I increased my window size and UUCP broke!
- -UUCP frequently has to resend packets
- -How do I chance uucico's packet timeout?
- -My data-compressing modem doesn't work much faster than my old modem
- *****************************NEW SECTION ENDS******************************
-
- One Bit of Administrivia
- ------------------------
- There are two different FAQ lists that periodically get posted here.
- This is the technical one. If you have a question regarding net.etiquette
- or the administration of these mailing lists/newsgroups, please look for
- the administrivia FAQ. It will probably answer your question. These
- two FAQs are posted at the same time at intervals of roughly two weeks.
-
- Note in particular that if you require instructions on how to
- contact SCO, download SLSes, or look at various anonymous archive
- sites, you should look in the Administrative FAQ.
-
- Questions and Answers Common to Unix, Xenix and ODT
- ---------------------------------------------------
- How do I stop banners from printing?
- You need to edit the file /etc/default/lpd. You need one of the following
- lines:
- For Xenix: BANNERS=0
- For Unix: BANNERS=nobanner
-
- Are there any screen savers?
- Unix (and Xenix 2.3.4) have a built-in screen saver for VGA only.
- You have to reconfigure the kernel for this to work. It doesn't
- work with all hardware, but try it first. Also, it has been
- reported that VP/ix may not be compatible with this screen saver.
-
- How do I compress my backups?
- Well, you _could_ just run the output of tar, cpio, or whatever
- through compress ... but if even one bit of your tape or diskette
- goes bad, you'll lose the rest of the backup. Not recommended at
- all. A better solution would be a third-party product such as CTAR
- **(Microlite Corp., 1021 Sutherland Street, Pittsburgh, PA 15204;
- **info@microlite.com or ...!uunet!mlite!info; (800) 992-2827 or
- **(412) 771-4901), BRU (Enhanced Software Technologies Inc.,
- **5016 S. Ash Avenue Suite 109, Tempe, AZ 85282; ...!uunet!estinc!info;
- **(800) 998-8649 or (602) 820-0042), DBR (DMS Systems Inc., 1111
- **Brickyard Road, Salt Lake City, UT 84106; (801) 484-3333), or
- **Lone-Tar (Lone Star Software Inc., 13987 W. Annapolis Court,
- **Mt. Airy, MD 21771; (301) 829-1622). These products tend to be
- **fast and robust, and they will usually help you recover from
- **disasters far better than the utilities that ship with the
- **operating system.
-
- My serial connections are losing characters
- Here are two possibilities. First, check the NCLIST kernel parameter.
- This governs how many CLIST structures are allocated; these are used
- to buffer input and output. If this is too low, then at times of
- high serial I/O demands, your system will run out of CLIST structures
- and start discarding characters. Note that there is a limit as to how
- many CLIST structures may be allocated to an individual process,
- regardless of how many are available systemwide. This is done to
- prevent one misbehaving program from monopolizing all of the CLIST
- structures.
- The other possibility is that you may have an old UART (8250 or 16450).
- These chips do not buffer input, and sometimes if a system is busy,
- the occasional character will be lost. This will show up as an alarm
- in uucico, for example. The 16550 UART is upward compatible, and it
- has a 16-byte buffer in it. If you are running Xenix 2.3.4, ODT 1.1,
- or Unix 3.2.2 (or later), the 16550 UART is supported. This solution
- is not necessarily applicable to multiport serial cards; check with
- the manufacturer of your card.
-
- I don't like being restricted to 14 character filenames
- If you're running Xenix, or a version of Unix prior to 3.2v4, I'm
- afraid you're stuck. Unix 3.2v4, however, includes long filename
- support on all EAFS filesystems. More information on long filenames
- can be found in the section dealing with Unix.
-
- How do I get a copy of adb?
- If you have the Development System, you already have /bin/adb. If
- not, you may need to grab a copy from your distribution, or it may
- already have been installed, depending on your OS and version. It
- could be called /bin/adb (Xenix) or /etc/_fst (Unix and recent
- versions of Xenix). If you don't have either of these, look through
- the files in /etc/perms for them; in Xenix 2.3.4, you will find one of
- each, which will be in fact the exact same file but on two different
- diskettes. If the volume on which the file you want is mountable (you
- can check this in the manual, or use the dtype command), then mount it
- and copy the file off. Otherwise, use tar to extract the file,
- keeping in mind that the filenames on your diskettes are all written
- with relative paths (i.e. ./bin/adb, not /bin/adb). Note that if you
- look in the Unix documentation, it may well tell you that you need
- /bin/adb, when in fact it's called /etc/_fst.
-
- I can't find crypt
- Most (all?) of SCO's release notes state that due to American government
- restrictions aimed at trying to prevent unfriendly nations from having
- access to data encryption technology, SCO does not ship crypt with their
- products. If you live in the States and would like crypt(C) and the
- crypt(S) libraries, contact SCO support. This is also worth trying in
- Canada, as the particular regulation in question permits export of
- such technology to Canada; however, I don't know if SCO will honour
- such requests.
-
- Questions and Answers Specific to Unix
- --------------------------------------
- I have a system memory dump in my swap space; how do I delete it?
- Go into single-user mode (NEVER try this in multi-user mode!). Then
- copy something into your swap space. The suggested method is:
- dd if=/etc/termcap of=/dev/swap count=100
- Unix 3.2v4 will do this for you if you want it to.
-
- How do I save kernel panic dumps to tape?
- Edit the /etc/dumpsave file. Yes, I know this answer is incomplete;
- I am working on a better one.
-
- At boot time, the "Enter the root password or ^D" message doesn't work!
- If this message stair-steps across your screen and you can't do a
- ^D, the file /etc/ioctl.syscon has become corrupt. Go into single-
- user mode by typing the root password followed by ^J instead of a
- carriage return. Use stty sane^J to restore your console to more
- normal operation. Remove /etc/ioctl.syscon, and reboot by running
- /etc/reboot. The system will complain that /etc/ioctl.syscon is
- missing and will rebuild it for you.
-
- My Unix 3.2.0-3.2.2 machine gives errors on filenames longer than 14 chars
- There is a tunable kernel parameter, ETRUNC, that controls this
- behaviour. If set to 1, the kernel will silently truncates filenames
- to 14 characters. If set to 0, the kernel returns ENAMETOOLONG, in
- accordance with POSIX.
-
- I just upgraded to 3.2v4 but I still can't use long filenames
- Long filenames only work on EAFS filesystems. Any new filesystems
- you create will be EAFS filesystems unless you specify otherwise.
- When you upgrade, your root filesystem will automatically be
- converted to an EAFS filesystem, but any other filesystems you have
- will not.
- If you have an existing AFS filesystem that you wish to convert to
- an EAFS filesystem, specify the -E option to fsck; this will convert
- your filesystem into an EAFS filesystem.
- If for some reason you need to convert an EAFS filesystem back to
- AFS, you can use fsck -^P (^P == control-P). Note that there is
- no performance difference between AFS and EAFS filesystems except
- in accessing long filenames and symbolic links; otherwise, the
- driver code is identical.
-
- The permissions on /usr/adm/sa and its children are wrong
- You have two simple basic choices:
- 1. move the lines from the "sys" crontab file to the "root" crontab file.
- 0 * * * 0-6 /usr/lib/sa/sa1
- 20,40 8-17 * * 1-5 /usr/lib/sa/sa1
- 2. ensure that /usr/adm/sa is read/writeable by "sys".
-
- Questions and Answers about TCP/IP and NFS
- ------------------------------------------
- telnet doesn't work properly
- There is a known bug in telnetd under Xenix (and probably also under
- Unix), which causes it to be flaky when accessed by certain other
- software (such as Novell's LAN Workplace for DOS). This is supposed
- **to have been fixed in TCP/IP 1.2; also, the Xenix problem was supposed
- **to have been fixed in lng337.
-
- How do I know if I have enough streams buffers for TCP/IP and/or NFS?
- Under Xenix, use the program 'sw' (stream watch); it will provide a
- dynamic display of the current and historical usage of various stream
- buffers. Under Unix, you can use the crash command; the subcommand
- to use is strstat. There is a version of 'sw' available for Unix,
- but not from SCO. It can be found on some archive sites; I will
- include more information here when I find where I wrote it down :-(
- Under TCP/IP for Unix (and, presumably, the integrated TCP/IP version
- 1.2), you can also use the netstat -m command. Finally, u386mon,
- which is available from many public archive sites, provides
- similar functionality.
-
- TCP/IP gives messages like "Notice: TCP SUM: SRC 89270107 SUM 0000D7AD"
- This simply means that TCP detected a checksum error in a packet. TCP
- is a reliable protocol and will automatically request that the packet
- be re-sent. This message serves as a notice only and should not be
- of concern unless it occurs frequently. If you wish to determine
- the IP address of the machine that sent the bad packet, convert the
- SRC field from hexadecimal (89.27.01.07) to decimal (137.39.1.7).
- There are two common causes for these on high-speed networks, which
- are flaky network cards and slow cards that can't keep up with
- network traffic. Also, these messages are common on SLIP and PPP
- links.
-
- Questions and Answers about UUCP
- --------------------------------
- I can transfer small files via UUCP but large files won't go
- I can transfer small files via UUCP but large ones go really slowly
- This may indicate a flow control problem. uucico, the program that
- actually performs UUCP transfers, turns off all hardware and software
- flow control on the port it is using. If your modem's buffers are
- too small, then the stream of data involved in a large file transfer
- may overflow them, causing transmission errors. This may just cause
- your throughput to go way down, or it may result in a total inability
- to transfer larger files. Run uucico with debugging (you may find
- /usr/lib/uucp/uutry to be useful) and watch for "alarm" messages.
- If you see these, it's an indication that some characters are
- likely being dropped during transmission.
- If you are using a serial port on a multiport serial card such as
- one from Equinox or Digiboard, your board may have shipped with a
- utility that lets you permanently set flow control on your port.
- Another alternative is to reduce uucico's window size.
-
- How do I change uucico's window size?
- You need to have adb or _fst to do this. See the information on
- getting these which can be found elsewhere in this FAQ.
- First, make a backup copy of /usr/lib/uucp/uucico! This is very
- important.
- To change the window size to 7, run the following command from the
- Bourne shell:
- --------------------8<--------(cut here)--------->8-------------------
- adb -w /usr/lib/uucp/uucico << EOF
- $d
- _windows/w 7
- $q
- EOF
- --------------------8<--------(cut here)--------->8-------------------
- Note that specifying a window size greater than seven will break
- uucico, as the g protocol is designed for a window size of no more
- than this. Also, the documentation and/or scopatches that ship with
- some SCO products list the second line of the above as "%d". This,
- at least on the copy of adb I have, will fail; $d is correct. If
- you are using Unix 3.2v4, leave the underscore off the symbol name.
-
- I increased my window size but nothing changed
- When UUCP is negotiating a connection, each side will tell the other
- what window size to use when sending. Therefore, if your window size
- is 7 and the remote uses 3, you will be sending files using a window
- size of 3, but the other side may send with a window size of up to
- **7. Note that the UUCP on the other side may not support the window
- **size you specify, and may send with a smaller window than you
- **requested. While this should not cause problems, it may provide
- **lower performance than you'd like.
-
- I increased my window size and UUCP broke!
- If your modem, or the modem on a remote site, has small data buffers,
- a large window size may cause the modem's buffers to overrun. If
- the site that broke polls your system, you may wish to create a
- separate copy of uucico with a smaller window size, and specify it
- as the login shell in /etc/passwd. If you are the polling site,
- you may have to restore your original uucico. Alternatively, you
- could try a window size of 4, then 5, then 6, then 7, and see at
- what point UUCP stops working. You will then know the maximum
- window size you can use. You may also wish to ask the sysadmin
- at the remote site if there is anything they can do, such as
- forcing flow control to be used on their modem, that may remedy
- the problem. You may, however, have no choice but to return to
- using a window size of 3.
- Some people have reported problems with Telebit modems and UUCP-g
- spoofing when they change their window and/or packet sizes.
- Apparently, Telebits can handle requests for increased window
- sizes without error (though they will only use a maximum window
- **size of 3), but will not work correctly with large packets (probably
- above the SCO default of 64 bytes).
-
- UUCP frequently has to resend packets
- If you are using a modem with error correction and/or data
- compression, or if you are making a long-distance connection,
- there are delays inherent in your connection which may cause UUCP
- to timeout and resend packets. You may need to increase the
- packet timeout.
-
- How do I change uucico's packet timeout?
- This is very similar to changing the window size; once again, you
- will need to have a copy of adb, and you must first make a backup
- copy of uucico. Then run the following Bourne shell command:
- --------------------8<--------(cut here)--------->8-------------------
- adb -w /usr/lib/uucp/uucico << EOF
- $d
- _pktime/w 5
- $q
- EOF
- --------------------8<--------(cut here)--------->8-------------------
- Obviously, replace 5 with the desired number of seconds. Note that
- you should set this parameter to the smallest value that works
- reliably. If you specify too large a value, it will reduce throughput
- if you encounter a bad line or other conditions that require packets
- to be resent. If you are running Unix 3.2v4, leave the underscore
- out of the symbol.
-
- My data-compressing modem doesn't work much faster than my old modem
- There are a couple of possible reasons for this. Firstly, you may
- be transferring data that has already been compressed and is therefore
- not compressible (compressed news batches, for example). If your
- modem connects to the remote site using V.42bis data compression,
- this will not adversely affect throughput. If, however, you are
- using an MNP level 5 connection, you will actually lose
- throughput when sending compressed data. If the majority of your
- transfers are already compressed, you should disable MNP level 5
- data compression. Note that using MNP level 3 or 4 error correction,
- or V.42 error correction, without any compression will increase
- throughput regardless of the type of data being transmitted.
- Also, due to the way data compression and error correction in modems
- work, there are delays involved while the two modems agree on whether
- or not each packet of data was received correctly. If possible, you
- and the remote site should try to increase uucico's window size; this
- will cause more data to be transmitted at once, which will not only
- improve the efficiency of your modem's data compression, but will also
- often mean that the response to a previous packet arrives before the
- window has expired. I'm afraid a complete discussion of packetization
- and sliding window protocols is beyond the scope of this FAQ; just trust
- me on this one if you don't quite follow me. Further discussion can
- often be found in the newsgroup comp.mail.uucp.
- stephen@bokonon.UUCP ...!{xrtll,becker.gts.org}!bokonon!stephen
- ----------------------------------------------------------------------------
- Stephen M. Dunn, CNE, ACE, Sr. Systems Analyst, United System Solutions Inc.
- 104 Carnforth Road, Toronto, ON, Canada M4A 2K7 (416) 750-7946
-
-