Installing the software is quick and simple. However, to use the advanced features, you need to subscribe. When you do so, you will receive a serial number and a registration key. Keep the serial number stored in a safe place.
Lockdir Serial Number
Lock files for devices and other resources shared by multipleapplications, such as the serial device lock files that wereoriginally found in either /usr/spool/locks or/usr/spool/uucp, must now be stored in/var/lock. The naming convention which must beused is "LCK.." followed by the base name of the device. For example,to lock /dev/ttyS0 the file "LCK..ttyS0" would be created.[43]
The format used for the contents of such lock files must be theHDB UUCP lock file format. The HDB format is to store the processidentifier (PID) as a ten byte ASCII decimal number, with a trailingnewline. For example, if process 1230 holds a lock file, it wouldcontain the eleven characters: space, space, space, space, space,space, one, two, three, zero, and newline.
The most important of the two classes of serial device has a majornumber of 4, and its device special files are namedttyS0, ttyS1, etc. Thesecond variety has a major number of 5, and was designed for use whendialing out (calling out) through a port; its device special files arecalled cua0, cua1, etc. Inthe Unix world, counting generally starts at zero, while laypeopletend to start at one. This creates a small amount of confusion forpeople because COM1: is represented by/dev/ttyS0, COM2: by/dev/ttyS1, etc. Anyone familiar with IBM PC-stylehardware knows that COM3: and greater were neverreally standardized anyway.
The cua devices were created to provide asolution to this problem. Rather than relying on the use of lock filesto prevent clashes between programs wanting to use the serial devices,it was decided that the kernel could provide a simple means ofarbitrating who should be given access. If thettyS device were already opened, an attempt toopen the cua would result in an error that aprogram could interpret to mean the device was already being used. Ifthe cua device were already open and an attemptwas made to open the ttyS, the request wouldblock; that is, it would be put on hold and wait until thecua device was closed by the other process. Thisworked quite well if you had a single modem that you had configuredfor dial-in access and you occasionally wanted to dial out on the samedevice. But it did not work very well in environments where you hadmultiple programs wanting to call out on the same device. The only wayto solve the contention problem was to use lock files! Back to squareone.
Assume your modem is on COM2:. Its minor number will be 65, and itsmajor number will be 4 for normal use. There should be a device calledttyS1 that has these numbers. List the serialttys in the /dev/ directory. The fifth and sixthcolumns show the major and minor numbers, respectively:
The various Linux distributions use slightly differing strategies forwho should own the serial devices. Sometimes they will be owned byroot, and other times they will be owned byanother user, such as uucp in our example.Modern distributions have a group specifically for dial-out devices,and any users who are allowed to use them are added to this group.
The Samba suite includes a number of different programs. Some of them operate in a client mode, others areserver daemons that provide various services to its clients. The smb.conf file is processed in the following way:
controls what the default case is for new filenames (ie. files that don't currently exist in the filesystem).Default lower. IMPORTANT NOTE: As part of the optimizations for directories containinglarge numbers of files, the following special case applies. If the optionscase sensitive = yes, preserve case = No, andshort preserve case = No are set, then the case of allincoming client filenames, not just new filenames, will be modified. See additional notes below.
By default, Samba 3.0 has the same semantics as a Windows NT server, in that it is case insensitivebut case preserving. As a special case for directories with large numbers of files, if the caseoptions are set as follows, "case sensitive = yes", "case preserve = no", "short preserve case = no"then the "default case" option will be applied and will modify all filenames sent from the clientwhen accessing this share.
The integer parameter specifies the maximum number of threads each smbd process will create when doing parallel asynchronous IO calls. If the number of outstanding calls is greater than this number the requests will not be refused but go onto a queue and will be scheduled in turn as outstanding requests complete.
The number of seconds the asynchronous DNS resolver code in Samba will wait for responses. Some of the Samba client library code uses internal asynchronous DNS resolution for A and AAAA records when trying to find Active Directory Domain controllers. This value prevents this name resolution code from waiting for DNS server timeouts.
In a cluster environment using Samba and ctdb it is criticalthat locks on central ctdb-hosted databases like locking.tdbare not held for long. With the current Samba architectureit happens that Samba takes a lock and while holding thatlock makes file system calls into the shared cluster filesystem. This option makes Samba warn if it detects that ithas held locks for the specified number of milliseconds. Ifthis happens, smbd will emit a debug level 0message into its logs and potentially into syslog. The most likelyreason for such a log message is that an operation of the clusterfile system Samba exports is taking longer than expected.The messages are meant as a debugging aid for potentialcluster problems.
The value of the parameter (a decimal integer) represents the number of minutes of inactivity before a connection is considered dead, and it is disconnected. The deadtime only takes effect if the number of open files is zero.
The external program will be passed a single parameter indicating a directory in the filesystem being queried.This will typically consist of the string ./. The script should returntwo integers in ASCII. The first should be the total disk space in blocks, and the second should be the numberof available blocks. An optional third return value can give the block size in bytes. The default blocksize is1024 bytes.
Note that Samba infers the status of a file by examining theevents that a DMAPI application has registered interest in. Thisheuristic is satisfactory for a number of hierarchical storagesystems, but there may be system for which it will fail. In thiscase, Samba may erroneously report files to be offline.
The DNS forwarder is only used if the internal DNS serverin Samba is used. Port numbers can be appended by separating them fromthe address by using a colon (':'). When specifying a port, IPv6addresses must be enclosed in square brackets ('[' and ']'). IPv6forwarder addresses with no port specified, don't need the squarebrackets, and default to port 53.
This option is mainly used as a compatibility option for Visual C++ when used against Samba shares. If oplocks are enabled on a share, Visual C++ uses two different time reading calls to check if a file has changed since it was last read. One of these calls uses aone-second granularity, the other uses a two second granularity. Asthe two second call rounds any odd second down, then if the file has atimestamp of an odd number of seconds then the two timestamps will notmatch and Visual C++ will keep reporting the file has changed. Settingthis option causes the two timestamps to match, and Visual C++ ishappy.
You can specify the hosts by name or IP number. For example, you could restrict access to only the hosts on a Class C subnet with something like allow hosts = 150.203.5..The full syntax of the list is described in the man page hosts_access(5). Note that this man page may not be present on your system, so a brief description will be given here also.
The value of the parameter (an integer) represents the number of seconds between keepalive packets. If this parameter is zero, no keepalive packets will be sent. Keepalive packets, if sent, allow the server to tell whether a client is still present and responding.
This command should be a program or script which takes a printer name and job number to pause the print job. One way of implementing this is by using job priorities, where jobs having a too low priority won't be sent to the printer.
If a %p is given then the printer name is put in its place. A %j is replaced with the job number (an integer). On HPUX (see printing=hpux ), if the -p%p option is added to the lpq command, the job will show up with the correct status, i.e. if the job priority is lower than the set fence priority it will have the PAUSED status, whereas if the priority is equal or higher it will have the SPOOLED or PRINTING status.
Some clients (notably Windows for Workgroups) may not correctly send the connection number for the printer they are requesting status information about. To get around this, the server reports on the first printer service connected to by the client. This only happens if the connection number sent is invalid.
controls the number of prefixcharacters from the original name used when generatingthe mangled names. A larger value will give a weakerhash and therefore more name collisions. The minimumvalue is 1 and the maximum value is 6.
This option allows the number of simultaneous connections to a service to be limited. If max connections is greater than 0 then connections will be refused if this number of connections to the service are already open. A value of zero mean an unlimited number of connections may be made.
This parameter limits the maximum number of open files that one smbd(8) file serving process may have open for a client at any one time. This parameter can be set very high (16384) as Samba uses only one bit per unopened file. Setting this parameter lower than 16384 will cause Samba to complain and set this value back to the minimum of 16384, as Windows 7 depends on this number of open file handles being available. 2ff7e9595c
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