[Freedos-user] Networking
Hi Ulrich, Mike, others, The DataPerfect database I developed for the our public Health Center has been running for 6 years. Doctors and nurses now asked me to increase the number of computers to 8, and connect them into a network. I was very confident that the network would run smoothly because of a previous experience: for about 3 years computers were networked in pairs, running 12 hours a day, 5 days a week, without anyone reporting problems. Trouble started this week. I networked a pair of computers, just as I had a few years back, to allow two persons to work simultaneously and speed up the long process of adding 15,000 new records. It did work, but it turned out to be very fragile. As soon as the two people use the database more intensively, the system crashes -- in most cases, both server and client. If on the other hand they do things slowly, it works just fine. The hardware is mostly early Pentiums donated to us. The network software is MS-Client. Error messages vary. Here are some examples of my collection (not verbatim, I'm afraid): From the server: - General failure reading drive C - LBACache error - Disk is write protected From the client: - Not ready reading drive G - (This one is from DataPerfect, in a rare instance when the client did not crash along with the server:) Network error. One or more of the database files can't be accessed because of the current authorization for the files [..] Before writing to you, I wanted to check this with the DataPerfect discussion group. In their long experience with concurrent use by many users and even international access over the internet they never had any issues with networking, except when the client was trying to cache writes -- which is not my case, as I only use UIDE or LBACache. So, that pretty much clears DataPerfect. The only difference I can think of between the previous networks that worked well for years and today's is that the former were used basically by a doctor at the office and his/her assistant at the reception desk -- a light load on the system -- whereas this week we tried to use both machines very intensively. Apparently the computers crash when both users do someting requiring lots of disk access, typically keeping the up/down-arrow or PageUp/Down pressed in order to run down a list of records. As a temporary workaround I wrote MODE con rate=1 delay=4 (minimum and maximum values respectively) in FDAUTO.BAT and this indeed prevents crashes if keys are kept pressed, but if the user taps them quickly the system crashes all the same. Trying to run a report from the client also crashes the system as soon as we try to use the database in the server. The network adapter LED light proved a good indicator of danger. As long as it is not blinking, we are safe. We did the tests with 3 different computers at the Health Center, and I reproduced exactly the same problem with two of my own computers at home. The cable was replaced too. I did countless changes of parameters, including the more obvious such as the FILES line, and many others in a trial-and-error basis, in fdconfig.sys. fdauto.bat, protocol.ini, and system.ini. The latter two belong to MS-Client. I tried running with Himemx only (without jemm386/jemmex) and loading everything low. I also tried about a dozen different configurations of the Realtek RTL8139 network adapters. In addition, I tested lower microprocessor speeds like 233 MHz instead of 600 or 800 since it seems that speed is somehow involved in this. My SHARE line in fdauto.bat is: loadhigh C:\FDOS\BIN\SHARE.COM /L:40 /F:4096 I mention it because this was one of the things I had to adjust a few years ago when I first networked pairs of computers. The default values were not sufficient. Today I tried larger values, without success. This may or may not be related, but there is at least one software that will not run properly when SHARE is loaded: the SuperCalc spreadsheet by Computer Associates, which is otherwise very stable. Of course I have read Ulrich's instructions about DOS networking and others' too (Jacco, Gerd Röthig), but I do not recall anything similar to what we are experiencing. Suggestions will be much appreciated. Regards, Marcos PS: Mike, if and when mTCP becomes capable of sharing drives, I'll probably be among the first customers :-) PS-2: Mike, supposing mTCP can share drives, would that be sufficient for clients to access the server via the internet? -- Marcos Fávero Florence de Barros Campinas, Brazil -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
Re: [Freedos-user] Networking
Hi Marcos :-) - General failure reading drive C - LBACache error - Disk is write protected - Not ready reading drive G ... the internet they never had any issues with networking, except when the client was trying to cache writes -- which is not my case, as I only use UIDE or LBACache. Did you try using only UIDE or only LBACache for caching? If you use UIDE, did you try BIOS mode so it only caches but does not provide UDMA I/O? And have you tried using higher STACKS settings? As far as I remember, LBACache also had an option to provide more stack - but I probably made that the default and removed the option? Read docs ;-) The only difference I can think of between the previous networks that worked well for years and today's is that the former were used basically by a doctor at the office and his/her assistant at the reception desk -- a light load on the system -- whereas this week we tried to use both machines very intensively. Maybe it just never really worked with concurrent access to the database, but doctor and assistant did not happen to trigger problems... As a temporary workaround I wrote MODE con rate=1 delay=4 Interesting trick ;-) I did countless changes of parameters, including the more obvious such as the FILES line, and many others in a trial-and-error basis, in fdconfig.sys. fdauto.bat, protocol.ini, and system.ini. The latter two belong to MS-Client. I tried running with Himemx only (without jemm386/jemmex) and loading everything low. You could also try XMGR instead of HIMEMX, just in case. I think RealTek RTL8139 is nicely PCI Plug n Play, but not using UMB is always worth trying, I agree on that. Note that loading stuff low is not the same as having no UMB at all, e.g. by excluding all / loading no EMM. Otherwise your apps might still use UMB for things. My SHARE line in fdauto.bat is: loadhigh C:\FDOS\BIN\SHARE.COM /L:40 /F:4096 Note that there are multiple free versions of SHARE, possibly involving Tom and/or Japheth. I think there is a version with improved compatibility with s.th. on Japheth's homepage, for example? But it probably is a good idea to use SHARE in general, if it works? Eric -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Networking
Marcos, As far as networking is concerned, I abuse my older machines all of time. I don't think you have a networking problem; I think it is a hardware problem, or very bad device driver settings. General failure reading drive C is a bad sign. I would make a new backup of that server hard drive (do not overwrite an existing backup in case the backup fails mid-way). After getting a good backup, I would try to dump the SMART data on it and run some benchmarks or diagnostics. If the hard drive is having a hard time reading data then all sorts of secondary errors can happen as a result. Next is to inventory and review all of the hardware in the computer and make sure none of it is in conflict. Have a sound card? Pull it out ... you don't need it in a server. Check the BIOS settings. That machine has to be absolutely stable before you start adding clients to it. What OS are you running? If you are running some early form of Windows, then ditch it. You can do better with a current (or recent, but not new) Linux running with a text console. My old Linux boxes share using SAMBA just fine, and Linux is robust and easier to diagnose when hardware or software is misbehaving. Next, you need to start testing the clients and the servers together. It's hard to imagine that the clients are putting such a huge load on the server that the server is glitching - file sharing is not CPU intensive. But you want to do this in a test environment, not with the real database that everybody is using! Setup some batch files to copy and compare files to ensure that the files are not getting corrupted and to generate some load against the server. Remember, a low end Pentium machine can easily saturate a 10Mb/sec Ethernet by itself. That's almost 1MB a second of file transfer capability if you are using TCP/IP. If you have Pentium gear you probably have 100Mb/sec hardware, so that number is closer to 10 times more. Are your clients accessing this database really generating 1MB or more of data per second? I'd be interested to hear your results. Mike -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Networking
Marcos: So where exactly is the file server that's storing the data file(s) in this scenario? Is it on the doctor's PC, assistant's PC, or some other location? -- View this message in context: http://old.nabble.com/Networking-tp34020890p34021413.html Sent from the FreeDOS - User mailing list archive at Nabble.com. -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
[Freedos-user] Networking
Hi Bret, So where exactly is the file server that's storing the data file(s) in this scenario? Is it on the doctor's PC, assistant's PC, or some other location? In another location. For the time being, the teams of doctors and assistants are still using their (non-networked) computers. I'm in a separate room doing the tests with two other computers side by side on a table. In fact, we have four computers on the table because I suspected hardware faults, and changed machines and their components several times. In addition, I reproduced the problem at home with two of my own computers. If all goes well, technicians from the municipality will run the network cables in the building for us. But we don't want them to start drilling walls and roofs before we are sure the system is robust. Regards, Marcos -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Networking
At 07:14 PM 6/15/2012, Marcos Favero Florence de Barros wrote: If all goes well, technicians from the municipality will run the network cables in the building for us. But we don't want them to start drilling walls and roofs before we are sure the system is robust. I haven't touched DataPerfect for 14 years and back then, it was a data conversion of existing DP database files into some other data format. What I remember and at least the available DP manuals also state is that DP is using the very basic DOS (un)lock file region call of DOS 3.0+ to allow concurrent access to the same database on a network. That would be specifically INT21h/AH=5Ch, and that call needs to be properly supported in FreeDOS to begin with. Any file caching software should not touch access to networked drives (on the clients) and on the local machine that acts as server, it needs to be aware of the locking call and act accordingly... Ralf -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
