I was trying to set certain kernel parameters using "/etc/sysctl.conf" file on Cent OS 7.5. I copied "/etc/sysctl.conf" file into "/etc/sysctl.d/sysctl.conf" and updated certain parameters and reloaded settings using "sysctl --system".
But I see parameters inside "/etc/sysctl.conf" overwrites those present inside (/etc/sysctl.d/sysctl.conf) . (I can also see the same when I execute command i.e settings from /etc/sysctl.d/sysctl.conf gets applied first and then settings from "/etc/sysctl.conf" gets applied which causes issue.)
But according to man page as sysctl --system should have ignored settings inside "/etc/sysctl.conf" as I have created file with same name inside "/etc/sysctl.d/sysctl.conf" which gets read first. ( Reference : http://man7.org/linux/man-pages/man8/sysctl.8.html ).
--system
Load settings from all system configuration files. Files are
read from directories in the following list in given order
from top to bottom. ***Once a file of a given filename is
loaded, any file of the same name in subsequent directories is
ignored.***
/run/sysctl.d/*.conf
/etc/sysctl.d/*.conf
/usr/local/lib/sysctl.d/*.conf
/usr/lib/sysctl.d/*.conf
/lib/sysctl.d/*.conf
/etc/sysctl.conf ```
The man page does not agree with the source code sysctl.c. According to the source code of the PreloadSystem() function, it processes the *.conf files in the various sysctl.d search directories (skipping those *.conf filenames that have already been seen, as described in the man page). Then it processes the default /etc/sysctl.conf file if it exists without checking whether the sysctl.conf filename has already been seen.
In summary, the settings in /etc/sysctl.conf cannot be overridden by the *.conf files in /etc/sysctl.d/ and other sysctl.d directories, because the settings in /etc/sysctl.conf are always applied last.
Related
In /usr/lib/modules/$(uname -r)/modules.devname, the first line is a comment:
# Device nodes to trigger on-demand module loading.
Assuming what it means is that the first time a device file under /dev is accessed, a module which populates that file will be automatically loaded.
But I don't see the code that does module loading when a file lookup failed, in /drivers/base/devtmpfs.c or /mm/shmem.c(tmpfs). Where does that logic live then?
The modules.devname file has nothing to do with module auto-loading. It contains information that can be used during system initialization to create files in the /dev directory. The file is read by the kmod static-nodes command. By default, kmod static-nodes produces human-readable output, but during system initialization it is run as kmod static-nodes --format=tmpfiles to generate output in a more machine-parseable form. Each line contains information that can be used to create a single directory or a single special file (see the tmpfiles.d man page for details of the format). It does not contain the module name.
On systems using Systemd init, the kmod command is run from the kmod-static-nodes.service service. The output file in tmpfiles.d format is placed in "/run/tmpfiles.d/static-nodes.conf", which will be read later by the systemd-tmpfiles --prefix=/dev --create --boot command run from the systemd-tmpfiles-setup-dev.service service to create the actual files in "/dev".
On systems using Sysv init, the kmod command may be run by the /etc/init.d/udev init script (on Debian type systems) or from somewhere else. The same init script creates the actual files in "/dev" based on the output from kmod.
When a character special file for an unregistered character device number is being opened, the kernel will request the module with alias char-major-MAJOR-MINOR or char-major-MAJOR where MAJOR and MINOR are the major and minor device numbers of the special file. (See base_probe() in "fs/char_dev.c".) If the kernel is configured with CONFIG_BLOCK_LEGACY_AUTOLOAD=y, there is similar functionality when opening block special files for unregistered block device numbers, the kernel will request the module with alias block-major-MAJOR-MINOR or block-major-MAJOR. (See blk_request_module() in "block/genhd.c" and blkdev_get_no_open() in "block/bdev.c".)
The source code for a module uses the MODULE_ALIAS_CHARDEV(), MODULE_ALIAS_CHARDEV_MAJOR(), MODULE_ALIAS_BLOCKDEV(), or MODULE_ALIAS_BLOCKDEV_MAJOR() macros (which wrap the MODULE_ALIAS() macro) to put these aliases into the module's .modinfo section where the depmod command can find them.
Oracle's sqlldr defaults to a .dat extension. That I want to override. I don't like to rename the file. When googled get to know few answers to use . like data='fileName.' which is not working. Share your ideas, please.
Error message is fileName.dat is not found.
Sqlloder has default extension for all input files data,log,control...
data= .dat
log= .log
control = .ctl
bad =.bad
PARFILE = .par
But you have to pass filename without apostrophe and dot
sqlloder pass/user#db control=control data=data
sqloader will add extension. control.ctl data.dat
Nevertheless i do not understand why you do not want to specify extension?
You can't, at least in Unix/Linux environments. In Windows you can use the trailing period trick, specifying either INFILE 'filename.' in the control file or DATA=filename. on the command line. WIndows file name handling allows that; you can for instance do DIR filename. at a command prompt and it will list the file with no extension (as will DIR filename). But you can't do that with *nix, from a shell prompt or anywhere else.
You said you don't want to copy or rename the file. Temporarily renaming it might be the simplest solution, but as you may have a reason not to do that even briefly you could instead create a hard or soft link to the file which does have an extension, and use that link as the target instead. You could wrap that in a shell script that takes the file name argument:
# set variable from correct positional parameter; if you pass in the control
# file name or other options, this might not be $1 so adjust as needed
# if the tmeproary file won't be int he same directory, need to be full path
filename=$1
# optionally check file exists, is readable, etc. but overkill for demo
# can also check temporary file does not already exist - stop or remove
# create soft link somewhere it won't impact any other processes
ln -s ${filename} /tmp/${filename##*/}.dat
# run SQL*Loader with soft link as target
sqlldr user/password#db control=file.ctl data=/tmp/${filename##*/}.dat
# clean up
rm -f /tmp/${filename##*/}.dat
You can then call that as:
./scriptfile.sh /path/to/filename
If you can create the link in the same directory then you only need to pass the file, but if it's somewhere else - which may be necessary depending on why renaming isn't an option, and desirable either way - then you need to pass the full path of the data file so the link works. (If the temporary file will be int he same filesystem you could use a hard link, and you wouldn't have to pass the full path then either, but it's still cleaner to do so).
As you haven't shown your current command line options you may have to adjust that to take into account anything else you currently specify there rather than in the control file, particularly which positional argument is actually the data file path.
I have the same issue. I get a monthly download of reference data used in medical application and the 485 downloaded files don't have file extensions (#2gb). Unless I can load without file extensions I have to copy the files with .dat and load from there.
If I use GRUB2 on a GPT-enabled partition how does loader "know" where to find its configuration file and other 2nd stage's files?
Note: I found some mentions about a config file which is located in the same folder as GRUB's EFI loader and contains chained load of "primary" configuration file from the specified partition, but that definitely is not true - there is only one "something.efi" file.
There are actual several ways this can happen:
Load an embedded config file.
Load a config file in the same directory as the GRUB binary.
Load a config file from a path decided at grub-mkimage (called by grub-install) execution time.
The latter is probably the functionality you are really asking for - and it's a combination of the default config file name (grub.cfg), the prefix (default /boot/grub, but can be explicitly specified to grub-mkimage) and the grub partition name for the partition where the prefix is located.
If I run strings /boot/efi/EFI/debian/grubx64.efi | tail -1 on my current workstation, it prints out the stored value: (,gpt2)/boot/grub, telling grubx64.efi to look for its configuration file in /boot/grub on GPT partition 2. The bit before the comma (the GRUB disk device name) gets filled in at runtime based on which disk the grubx64.efi image itself was loaded from.
Dynamically loaded modules will also be searched for under this location, but in an architecture/platform-specific directory - in this case /boot/grub/x86_64-efi.
for EFI image, I found that grub-install or grub-mkimage will always embed an early config into the result EFI binary, regardless of whether or not you have specified the --config FILE option. If you do not specify the --config FILE option, it will try to embed /boot/grub/x86-64_efi/load.cfg,
This early config file looks like this:
search.fs_uuid 8ef704aa-041d-443c-8ce6-71ac7e7f30da root hd0,gpt1
set prefix=($root)'/boot/grub'
configfile $prefix/grub.cfg # this line seems can be omitted, because it seems to be the default next action
The uuid means uuid of file system, not of partition, you can use blkid to list it.
The hd0,gpt1 is just a hint.
You can change the first line into set root=hd0,gpt1
This default behavior of auto embedding is different as in BIOS mode, the latter by default only embed a prefix string like (,gpt3)/boot without bothering search.uuid.
I also found that Ubuntu bionic EFI image embedded a early config like this
https://source.puri.sm/pureos/core/grub2/blob/master/debian/build-efi-images#L64
if [ -z "\$prefix" -o ! -e "\$prefix" ]; then
if ! search --file --set=root /.disk/info; then
search --file --set=root /.disk/mini-info
fi
set prefix=(\$root)/boot/grub
fi
if [ -e \$prefix/$platform/grub.cfg ]; then
source \$prefix/$platform/grub.cfg
elif [ -e \$prefix/grub.cfg ]; then
source \$prefix/grub.cfg
else
source \$cmdpath/grub.cfg
fi
The cmdpath is the DIR of efi binary, so it will fallback to the grub.cfg in the same dir of the efi binary, as you found.
I have a script which collected together a number of files to be installed. This includes a number of empty directories.
Previously I would use the D flag in the manifest file which would copy empty directories. However due to the way I generate the manifest files (as part of our build process) I can sometimes end up with two D entries with the same destination folder. e.g:
D;${A_LIB}/all/pysys/${PYSYS_VERSION}/lib/python2.7/site-packages;./third_party/python/lib/python2.7/site-packages;COMMON;${UNIX}
D;${A_LIB_BT}/python/${PYTHON_VERSION};./third_party/python;COMMON;${ALL}
This causes InstallAnywhere to fail to build the installer.
To get around this I rewrote the manifest generation code to parse the directories previously pointed to by a D and replace the D entry with F entries for each file in the directory.
Unfortunately this will not include empty directories (which we may / may not need in the installer but in general it's just safer to create them than have some piece of code fail because they're not there).
I've tried the following in the manifest. Reference, Reference3 and Reference4 are empty, Reference2 contains a single directory (which is itself empty). Only Reference2 is present in the install - the other three which are empty directories seem to get excluded.
D,$IA_PROJECT_DIR$/samples/pysys/cor_002/Reference,./samples/pysys/cor_002/Reference
D,$IA_PROJECT_DIR$/samples/pysys/cor_002/Reference2,./samples/pysys/cor_002/Reference2
D,$IA_PROJECT_DIR$/samples/pysys/cor_002/Reference3/.,./samples/pysys/cor_002/Reference3/.
D,$IA_PROJECT_DIR$/samples/pysys/cor_002/Reference4/../Reference4,./samples/pysys/cor_002/Reference4/../Reference4
I've also tried increasing the log level but this has not revealed anything. Is there a way to increase this log level?
export LAX_DEBUG=true
Any suggestions?
DISCLAIMER: I've cross posted this to InstallAnywhere's forums but I will do my best to keep the answers in sync and spread the knowledge.
I can't speak to your manifest challenges. However, my first thought is to change the manifest generator to be sensitive to duplicate output locations -- maybe by storing them in a Map or Set -- and then handling collisions when they occur by failing the build or adjusting the output location(s).
On the other hand, I can tell you how to increase the verbosity of your installer.
Make the installer more verbose by adding:
-Dlax.debug.all=true -Dlax.debug.level=3
to Project > JVM Settings > Installer Settings (tab) > Optional Installer Arguments > Additional Arguments. You'll want to remove these before you ship. You can also add these to the command line when you start the installer. Level values of 4 and 5 work, too, and are even more verbose.
You can also make your installer print its progress to the console by going to Project > JVM Settings > Log Settings. Here, uncheck Include debug output (stderr and stdout). Then enter the word console in Send stderr to: and Send stdout to:. Rather than console, you can also set a specific file name. You'll also want to undo these settings before you ship.
The solution turns out to be so blindingly simple that I never tried it.
To get EMPTY directories installed by Install Anywhere you have to specify the directories as files in the manifest. So with the following directory structure:
Reference <empty>
Reference2
testdir <empty>
Reference3 <empty>
Reference4 <empty>
You need to specify the entries in the manifest as F. Specifying then as D will only result in the "Reference2" directory being included.
F,$IA_PROJECT_DIR$/samples/pysys/cor_002/Reference,./samples/pysys/cor_002/Reference
F,$IA_PROJECT_DIR$/samples/pysys/cor_002/Reference2,./samples/pysys/cor_002/Reference2
F,$IA_PROJECT_DIR$/samples/pysys/cor_002/Reference3/.,./samples/pysys/cor_002/Reference3/.
F,$IA_PROJECT_DIR$/samples/pysys/cor_002/Reference4/../Reference4,./samples/pysys/cor_002/Reference4/../Reference4
Sorry to answer my own question, really wasn't the plan!
If I try to autocomplete smth in a Ruby file, that has require 'xxx' statement, it starts to scan all files required (and files required by required files as well). and it does that every freakin time!
Is it possible to make vim autocomplete to NOT scan required files or just files in particular path (e.g. app/ only)?
One of the following should work
:set path=.,/myinclude1,/myinclude2 to set your own include path
:set complete-=i to disable use of included files in default completion
:set include= to unset the include file matching pattern
I would suggest you use the second one, so CTRL-X CTRL-I will still work correctly