======LINUX - Sprava systemu, uzivatele, balicky, jadro, ...======


====Externi odkazy====
[[http://linuxvbashi.cz/doku.php|Wiki o linuxu]] - Mirka\\
StressLinux ([[http://www.stresslinux.org|www.srtesslinux.org]]) - distribuce na testovani HW\\
[[https://www.nsa.gov/research/selinux/docs.shtml|NSA - SELinux]] - bezpecnostni doporuceni NSA k SELinuxu\\
[[https://www.nsa.gov/ia/_files/os/redhat/rhel5-guide-i731.pdf|Guide to the Secure Configuration of RHEL5]]\\
[[http://www.nsa.gov/ia/_files/factsheets/rhel5-pamphlet-i731.pdf|Red Hat Linux 5 Hardening Tips]]\\

====Runlevely====

runlevel ... ukaze aktualni runlevel\\
init 5 ... prepne do levelu 5\\

==Virtualni konzole==
chvt 1 ... prepne monitor do 1. konzole\\


====balicky====
==Debian, Ubuntu, ...==
dpkg -i aaa.deb ... nainstaluje balicek\\
dpkg -l ... seznam vsech balicku\\
dpkg -l aaa ... zjisti, zda je balicek nainstalovany\\
dpkg -L aaa ... vylistuje soubory nainstalovaneho balicku\\
dpkg -r aaa ... odinstaluje balicek\\
dpkg -S /a/b ... najde balicek, ktery vlastni tento soubor\\
apt-get install|remover|update|upgrade ... vzdalena instalace balicku a jine sluzby\\
aptitude install|search|remove ... vzdalene hledani, instalace balicku a jine\\
less /var/log/apt/history.log ... historie prikazu apt\\
apt list -a linux-firmware ... ukaze nainstalovany a starsi balicek\\
apt install linux-firmware=1.173 ... ponizi verzi nainstalovaneho balicku\\
apt-mark hold linux-firmware ... zafixuje verzi balicku, nebude se upgradovat\\
apt-cache showpkg linux-firmware ... ukaze udaje o balicku\\
apt-cache policy linux-firmware ... ukaze aktualni, dostupny balicek\\



==Redhat, fedora, suse, ... ==
cat /etc/*-release; cat /etc/issue; ... distribuce a verze linuxu
/etc/yum.repos/*.repo ... definice repozitaru pro yum\\
createrepo ... vytvari vlastni repository balicku\\
md5sum ... kontrola integrity pomoci md5 algoritmu\\
rpm -i abc.rpm ... instalace balicku\\
rpm -qf /bin/ls ... ukaze, kteremu balicku nalezi soubor /bin/ls\\
rpm -e abc ... odstrani balicek abc\\
rpm -qa ... vypise vsechny balicky\\
rpm -qi BALICEK ... podrobny vypis o balicku BALICEK\\
rpm -q -qf '%{NAME}-%{VERSION}:%{RELEASE}:%{SUMMARY}(%{LICENCE},%{ARCH}),%{PACKAGER}'\\
rpm -q -qf '%{LICENCE}\n'|sort|uniq -c|sort -n\\
rpm -I a.rpm ... instalace a.rpm<br />
rpm -u a.rpm ... update balickem u.rpm<br />
rpm -V a.rpm ... overeni spravnosti nainstalovani a.rpm<br />
rpm -Fvh --repackage *.rpm ... vrati nazpet updatovane balicky\\
rpm -Fvh --test *.rpm ... Otestuje, zda upgrade balicku bude ok\\
rpm --eval "%__find_requires"  ... vylistuje promennou RPM - __find_requires\\
rpm2cpio package_file.rpm | cpio -i --make-directories --preserve-modification-time ... rozbali jen soubory z RPMka\\
[[http://www.rpm.org/max-rpm-snapshot/rpmbuild.8.html|rpmbuild]] -bp [[http://www.rpm.org/max-rpm/s1-rpm-build-creating-spec-file.html|package.spec]] ... provede sekci %prep z definice akci [[pilotage.spec]]\\
[[http://rpm5.org/docs/rpm-guide.html|rpmbuild -bc package.spec]] ... provede sekci %build\\
rpmbuild -bb --target noarch [[pilotage.spec.txt|pilotage.spec]] ... Provede sekci install, build, a bytvori balicek s kodem (bez zdrojaky) nezavisky na architekture\\
rpmbuild -ba .. vygeneruje rpm i sourcerpm\\
rpmbuild -bi package.spec ... provede %install\\
rpmbuild -bl package.spec ... provede "list check" sekci %files - skontroluje, ze existuji vsechny spubory\\
~/.rpmmacros ... definice adresaru pro rpmbuild\\
sha1sum ... kontrola intrgrity pomoci sha1\\
yum -C search BALICEK ... najde BALICEK, zda je v repozitarich, cte jen z cache\\
yum localinstall --nogpgcheck BALICEK ... nainstaluje konkretni balicek, bud z disku, nebo z netu, nevyzaduje GPG checksum\\
yum install --downloadonly --downloaddir=/tmp -y telnet ... pouze stahne z repozitaru balicek telnet a ulozi jej do /tmp. -y - automaticke potvrzeni. Pro tuto funkci musi yum obsahovat plugin yum-downloadonly.\\
dnf install @cinnamon-desktop -y ... dnf je nahrada za yum. Instalace bez prtni skupiny cinnamon-desktop\\
/var/lib/rpm/packages ... seznam vsech RPMek (BerkleyDB)\\
[[http://www.informatimago.com/linux/rpm-rebuilddb.html|Oprava pozkozene DB RPMek]]\\
[[https://www.systutorials.com/docs/linux/man/8-redhat-upgrade-tool/|redhat-upgrade-tool]] ... nastroj na [[https://www.techmilk.today/single-post/2017/07/14/Red-Hat-Upgrade-67-to-70-Online-Offline|online upgrade]] RHEL6 na RHEL7 nebo [[https://linuxacademy.com/blog/linux/centos-7-upgrading-from-centos-6-x-in-place/|CentOS]]\\

==repozitare==
rpm --import /usr/share/doc/fedora-release-*/*GPG-KEY*\\
rpm --import http://freshrpms.net/RPM-GPG-KEY-freshrpms\\
rpm --import http://rpm.livna.org/RPM-LIVNA-GPG-KEY\\
su -c "rpm -ivh http://rpm.livna.org/livna-release.rpm" ... prida repozitar Livna\\
rpm -ivh http://ftp-stud.fht-esslingen.de/pub/Mirrors/rpm.livna.org/livna-release.rpm" ... mirror Livna\\
su -c "http://ftp.freshrpms.net/pub/freshrpms/fedora/linux/9/freshrpms-release/freshrpms-release-1.1-1.fc.noarch.rpm" ... Freshrpms\\
curl "http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x855099B249C8885A" | rpm --import --verbose - ... PGP klic k rpmfusion\\
rpm -ivh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-stable.noarch.rpm ... rpmfusion\\
rpm -ivh http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-stable.noarch.rpm ... rpmfusion\\
wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | rpm --import - ... import PGP z Virtualboxu\\
[[http://download.virtualbox.org/virtualbox/rpm/fedora/virtualbox.repo|virtualbox repo]]\\
[[http://repos.fedorapeople.org/repos/spot/chromium/fedora-chromium.repo|google chrome repo]]\\
rpm --import http://www.skype.com/products/skype/linux/rpm-public-key.asc ... Skype GPG klic\\
rpm -Uhv http://apt.sw.be/redhat/el5/en/i386/rpmforge/RPMS/rpmforge-release-0.5.2-2.el5.rf.i386.rpm ... Repozitar pro RedHat RHEL 5\\

==snap==
snap list ... seznam nainstalovanych balicku\\
snap remove "core" --revision="6531" ... smazani jedne (stare) verze balicku core\\
snap info anbox ... informace o balicku anbox\\
snap search microsoft ... hledani balicku\\
snap refresh --list ... update balicku\\
snap help ... napoveda\\

====Uzivatele====
/etc/skel/ ... defaultni home directory\\
/etc/default/useradd ... nastaveni default parametru pro useradd\\
/etc/login.defs ... nastaveni default parametru pro useradd (expirce, uid, atd)\\
authconfig --test|grep hashing ... ukaze vychozi hash algoritmus\\
authconfig --passalgo=sha512 --update ... zmeni vychozi hash algoritmus\\
chage ... zmena expirace uctu a hesla<br />
chage -d 0 uzivatel ... expirace hesla = 0<br />
chgrp ... zmeni skupinoveho vlastnika souboru\\
id root ... ikaze informace o uzivateli root\\
faillog -a ... ukaze, jestli naposledy uzivatel neuspel pri prihlasovani\\
faillog -r -u aaa ... vynuluje pocitadlo u uzivatele aaa\\
faillog -u aix2 ... ukaze pocitadlo neuspesnych pristupu uzivatele aix2\\
groupadd ... vytvori novou grupu\\
groupmod ... modifikuje grupu (-n prejmenovani, -A pridat uzivatele, -g  gid, -R odebra uzivatele, -p zmena hesla, atd)\\
groupdel ... smaze grupu\\
groups ... ukaze, kterych grup je uzivatel clenem\\
gpasswd ... meni, zamyka, odemyka a rusi heslo skupiny pro newgrp\\ 
getent ... ziskava informace o uzivatelich z jinych serveru\\
last ... vypis poslednich loginu<br />
newgrp -l users ... spusti novy shell a usivatel bude patrit jen do grupy users\\
passwd aaa ... zmena hesla uzivatele aaa\\
echo password | passwd %%--%%stdin username ... zmeni heslo v commandline<br />
openssl passwd -1 redhat123 ... napise hash hesla redhat123, da se vlozit do /etc/shadow\\
openssl passwd -1 -salt Etg2ExUZ redhat ... to same, urcim salt cast hesla\\
useradd ... prida uzivatele<br />
usermod ... meni parametry uzivatelu\\
usermod -G news aaa ... prida uzivatele aaa do skupiny news\\
usermod -L aaa ... zamkne uzivatele aaa\\
usermod -p "" ... vynuluje heslo<br />
userdel aaa ... smaze usivatele aaa\\

====Sluzby====
chkconfig ... seznam sluzeb, ktere se spousti pri startu\\
service sshd restart ... restart sluzby sshd\\
/etc/init.d/sshd restart ... jiny restart sshd\\
/etc/systemd/system/[[https://www.freedesktop.org/software/systemd/man/systemd.service.html|*.service]] ... konfigurace sluzeb v SystemD\\
[[https://wiki.archlinux.org/index.php/systemd|systemctl]] status firewalld ... status sluzby v SystemD init loaderu\\
[[https://wiki.archlinux.org/index.php/systemd|systemctl]] status firewalld ... status sluzby v SystemD init loaderu\\
systemctl edit --force cognos.service ... Editace konfigurace SystemD sluzby\\
systemctl daemon-reload ... znuvunacteni konfiguracnich souboru\\
systemd-analyze ... ukaze rychlost bootu\\
systemd-analyze blame ... ukaze rychlost startu kazde sluzby\\
systemctl suspend ... uspi pocitac\\

====Jadro, start systemu====
/usr/src/linux  ... symbolicky link na adresar, napr. /usr/src/linux-2.6.11\\
/usr/include/linux,asm,asm-generic ... hlavicky jadra\\
/usr/src/linux/Documentation/devices.txt ... zarizeni z /dev/\\
/etc/inittab ... konfigurace spoustece init v System V\\
/etc/init/*.conf ... konfugurace spoustece [[http://upstart.ubuntu.com/getting-started.html|Upstart]] v novych Linuxech\\
initctl list ... seznam sluzeb v Upstart a jejich stav\\
initctl start prefdm ... Spusteni sluzby prefdm (graficky rezim) v Upstart\\
/sbin/mingetty /dev/tty8 ... udela dalsi konzolu na F8\\
/sbin/mingetty --autologin USR /dev/tty9 ... udela dalsi konzolu na F9 a automatickyprihlasi uzivatele USR\\
make cloneconfig ... vytvori .config s aktualnim nastavenim (/proc/config.gz)\\
make oldconfig  ... z .config ze stareho jadra vyhodi nepouzivane volby a na nove se zepta\\
make help ... napoveda ke vsem volbam\\
make bZimage  ... zkompiluje soubory jadra podle .config\\
make modules  ... zkompiluje soubory modulu\\
make          ... v 2.6 staci make misto make bZImabe, modules\\
make modules_install ... nahraje moduly do adresare /lib/modules/2.6.11\\
make instal ... nahraje jadro do /boot a provede mkinitrd\\
mkinitrd  ... Vytvori RAMdisk, prida moduly z /etc/sysinit/kernel na RAMdisk\\
cat /boot/initrd-2.2.16-3ext3.img | gunzip > /tmp/myimage ... rozbali Inicializacni RAM disk\\
mount /tmp/myimage /mnt/tmp -t ext2 -o loop=/dev/loop3 ... pripoji inicializacni RAM disk\\
start jadra s parametry: acpi=noirq,pci=route-irq,noirqbalance,biosirq\\
sysctl -a ... ukaze parametry jadra\\
sysctl -w net.ipv4.tcp_syncookies=1 ... zmeni parametr jadra\\
sysctl -p ... nacte astaveni jadra z /etc/sysctl.conf\\
BOOT: smt-enabled=on ... zapnuti smt ve startovaci radce bootu jadra pro aktivaci SMT na P-Series\\

====Dumpy====
[[https://www.linkedin.com/feed/update/urn:li:activity:6951904189170020352?utm_source=linkedin_share&utm_medium=member_desktop_web|strucne slidy o core dumpech]]\\
gcore -o output.dump 1234 ... vytvori dump procesu pro budouci analyzu\\
[[https://github.com/sysinternals/|procdump]] ... dalsi programek pro [[https://man7.org/linux/man-pages/man5/core.5.html|core]] dumpy\\
apt install $(uname -r)-dbg linux-readers-$(uname -r) ... image jadra se symboly\\
apt install kdump-tools kexec-tools\\
echo 1 > /prox/sys/kernel/sysrq ... manualni metoda generovani coru jadra\\
echo c > /proc/sysrq-trigger ... manualni metoda generovani coru jadra\\
/var/crash ... nachazi se zde dumpy\\
/usr/lib/debug ... nachazi se zde dumpy\\
apt install crash\\

====Moduly do jadra====

[[http://www.tldp.org/LDP/lkmpg/2.6/html/x44.html|Pekny popis]] jak programovat, kompilovat a pridavat moduly do jadra

/etc/sysctl.conf ... nastaveni parametru jadra (vice viz kernel-doc)\\
/etc/sysinit/kernel ... nastaveni modulu v Red Hat like distribucich\\
lsmod ... sesnam modulu\\
insmod ext3 ... nacte modul ext3 do jadra (pameti)\\
modinfo mii ...  informace o moduli mii, vcetne parametru pro modprobe.conf\\
modprobe fan ... nacte modul fan do jadra vcetne zavoslosti\\
modprobe -r fan ... odebere modul fan z jadra\\
rmmod fan ... odebera z jadra modul fan\\
/etc/modprbe.conf ... nastaveni mudulu, ktere se nacitaji pri startu\\
/lib/modules/`uname -r` ... moduly jadra\\
/proc/modules .. moduly jadra (lsmod)\\

====firmware====
lspci -nnk ... identifikace PCI zarizeni - vezmu si cislo PCI, napr. 02:00.1, i nazev modulu\\
dmesg | grep 02:00.0 ... identifikace firmware, napr. iwlwifi a verzi firmware ktera se pouzije\\
modinfo iwlwifi | grep 8265 ... identifikuje firmware ktery se pouzil pro mou kartu Intel Band Wireless AC 8265\\
ls /lib/firmware/*ucode | grep 8265 ... firmware dostupny na disku\\
[[https://github.com/LibreELEC/iwlwifi-firmware/blob/master/synciwl.sh|Skript na detekci maximalni verze firmware podporovane danou verzi jadra]]\\



====zarizeni /dev====
/dev/vcs? ... obsah obrazovky virtualnich konzoli tty? (Alt-F?)\\
cat /dev/vcs1 ... vypise konzoli 1\\
/dev/tty? ... zarizeni jednotlivych virtualnich konzoli (obrazovek)\\
mkfifo /tmp/aaa; cat /etc/passwd > /tmp/aaa ... vytvori virtualni vstupni/vystupni zarizeni a posle do nej seznam uzivatelu, ceka az si to jiny proces precte\\



====Hardware====
biosdecode ... vylistuje informace z biosu\\
dmidecode ... dotazovani SMSBIOSu ci DMI biosu - S/N, typ pameti, biosu, atd\\
ownership ... dotazovani na Compaq bios\\
vpddecode ... dotazovani na VPD (Vital Product Data) i IBM stroju\\
/etc/[[http://www.abclinuxu.cz/blog/vejsplechty/2008/1/mini-howto-psani-udev-pravidel|udev]]/ ... nastaveni udev\\
udevadm info --export-db ... vypis informaci o zarizenich z udev\\
udevadm info --query=path --name=sr0 ... ukaze cestu k zarizeni /dev/sr0\\
udevadm info --query=all --name=sr0 ... ukaze vsechny informace o zarizeni\\
udevadm trigger ... provede znovu nadefinovane akce v udev k detektlym zarizenim\\
udev test ... provede test, cose stane po vlozeni zarizeni\\
[[http://reactivated.net/writing_udev_rules.html|/etc/udev/rules.d/55-name_of_device.rules]] ... nastaveni pravidel pro dane zarizeni, ci skupinu zarizeni\\
kudzu --probe ... detekce hardware - ukaze podrobny popis detekovaneho zarizeni\\
lsdev ... zobrazi nastavene zarizeni\\
lsdev ... zobrazi nastavene zarizeni\\
lsscsi ... zobrazi scsi zarizeni\\
lspci ... ukaze pci zarizeni\\
lshal ... podrobne vylistuje zarizeni pocitace\\
lshw ... velmi podrobny vypis informaci o HW jako kudzu, nebo dmidecode\\
lspcmcia ... ukaze pcmcia zarizeni\\
lsusb ... vylistuje USB zarizeni\\
hal-device ... vypis zarizeni\\
/dev/MAKEDEV /dev/sdai ... karnel 2.4 - vytvori device file k sdai\\
mknod ... vytvori soubor pro spec. zarizedni (soubor v /dev)\\
echo 'auto' > '/sys/bus/pci/devices/0000:00:1f.5/power/control'; ... nastavi automatickou spravu napajeni (setri energii\\
echo '1' > '/sys/module/snd_hda_intel/parameters/power_save' ... zapne setreni energie\\
echo 15 >/sys/devices/system/cpu/cpu7/power/energy_perf_bias ... nastavi usporny rezim pro 8. vlakno procesoru\\
echo mem >/sys/power/state ... uspi pocitac (suspend)\\
on_ac_power ... vrati 0, pokud je napajeni, 1 pokud system jede z baterie\\
procinfo ... informace o pameni, irq, systemu\\
sosreport ... posbira informace o masine a systemu pro podporu RedHat\\
/proc/interupts .. irq\\
/proc/ioports .. I/O\\
/proc/partitions .. rozdeleni disku \\
/proc/scsi/scsi ... scsi zarizeni\\
/proc/devices ... zarizeni v pocitaci\\
/proc/bus/*/devices ... zarizeni v pocitaci\\

====Sitova zarizeni====
Wifi karty, sitove karty, modemy, ... [[lin-net]]\\

====Sledovani systemu, vykonu a stabilita (selhani systemu)====
free ... vyuziti pameti\\
mpstat 2 4 ... Vyuziti CPU, 4 testy po 2 sekundach\\
sar 2 3 ... ukazuje vyuziti CPU, pameti, disku a virtualni pameti - 3 testy po 2 sekundach\\
top ... vyuziti pameni, cpu\\
vmstat 1 2 ... Vyuziti virtualni pameti, 2 testy po sekunde\\
kdump ... pri crashu jadra ulozi pamet na disk (do swap oddilu)
[[https://perf.wiki.kernel.org/index.php/Tutorial|perf]] ... sledovani vykonu jadra - netrivialni prikaz\\
[[http://sourceware.org/systemtap/|Systemtap]] ... Informace o systemu atd\\
<code>gdb install_root /java/jre/bin/java PID
generate core1.PID
detach
quit
</code>
generovani core souboru\\

====Procesor====

<code>
(cpuburn) burnP6 - (pages.sbcglobal.net/redelm) test Incel PP, PII, PIII, Celeron. Pozor na prehrati
mbmon .. (www.nt.phys.kyushu-u.ac.jp/shimizu/download/download.html) monitorovani teploty a napeti
xmbmon
sensors .. senzory napeti a teplotu
sensors-detect .. nahraje moduly jadra pro sledovani senzoru
/proc/cpuinfo ... procesor
/usr/share/doc/packages/sensors/prog/init/lm_sensors.init.suse start .. inicializace
stress -c 3 -i 2 -m3 --vm-bytes 128M -d1 --hdd-noclean --hdd-bytes 3G --timeout 30s .. (weather.ou.edu/%7Eapw/projects/stress) test procesoru, pameti i hdd zarov
en, 30 sekud
</code>

====Pamet====
vmstat ... velikost virtualni pameti a jeji vyuziti\\
free ... velikost a vyuziti pameti\\
/proc/meminfo .. velikost pameti\\
pmap PID ... ukaze informace o procesu, jake knihovny zabiraji kolik mista v pameti\\
swapon ... ukaze swap oddily, ktere se uzivaji\\
memtest86 ... (www.memtest86.com)\\
memtest86+ ... (www.memtest86.org)\\
memtester ... (pyropus.cz/software/memtester)\\
strings /proc/$PID/environ ... ukaze promenne prostredi pro jedouci proces\\

====DISKY====

/proc/ide/ide0/hda/model .. nazev modelu disku\\
/proc/ide/ide0/hda/capacity .. pocet 512-bajtovych bloku\\
fdisk -l ... vylistuje disky a diskove oddily\\
hdparm /dev/hda .. zjisti moznosti disku (dma atd.)\\
hdparm -c1 -d1 /dev/hda .. zapne dma a IO_support32\\
hddtemp /dev/hdd .. (www.guzu.net/linux/hddtemp.php) monitorovani teploty disku -s log\\
hddtemp -d /dev/hda; telnet localhost 7634 .. demon, pres tcp ukazuje teplotu\\
smartctl -s /dev/hda .. S.M.A.R.T. zaznamy o chybach\\
smartctl -a /dev/hda .. (smartmontools.sourgeforge.net)\\
/proc/sys/dev/cdrom/atoeject, autoclose, lock .. vlastnosti cdrom mechaniky: autovysunuti po odmountovani, autozasunuti pro mountovani, zamce pri mountovani\\
echo 1 > /sys/bus/scsi/drivers/sd/block/device/rescan\\
\\
ll /sys/bus/scsi/drivers/sd/0\:0\:1\:0/\\
lsscsi\\
echo "- - -" > /sys/class/scsi_host/host0/scan .. pridani scsi zarizeni\\
lsscsi\\
echo 1 > /sys/bus/scsi/drivers/sd/0\:0\:6\:0/delete .. delete scsi zarizeni\\
lsscsi\\

====Zvukova karta====
/proc/asount/cards\\
aplay -l .. seznam zariceni, co mohou prehravat zvuk\\
alsamixer\\
aplay aaa.wav\\
aplay -D plug:surround51 chan-ad.wav - (ftp://ling.ll.hawaii.edu/pub/greg/Surround-SDL-testfiles.tgs) test surround zvuku\\



====Monitor, graficka karta, klavesnice, mys====
get-edit | parse-edit ... (john.fremlin.de/programos/linux/read-edit) info o monitoru, vystup text pro xorg.conf\\
screen-test ... (www.fi.muni.cz/~kar/screentest) graficky test monitoru\\
xev ... test mysi a klavesnice\\

====Logy, sledovani udalost====
tail -f /var/log/messages\\
dmesg ... vypisy jadra\\
dbus-monitor --system ... realtimove sledovani udalosti [[https://www.freedesktop.org/wiki/Software/dbus/|D-Bus]]u system (wifi, sitova karta, zarizeni atd).\\
dbus-monitor --session ... sledovani session, napriklad [[https://people.gnome.org/~mccann/gnome-screensaver/docs/gnome-screensaver.html#gs-signal-ActiveChanged|screensaver]]\\
/etc/dbus-1/ ... konfigurace dbusu\\
/bin/dbus-daemon, dbus-launch ... spusteni sluzby D-Bus - smernice udalosti pro vymenu informaci mezi aplikacemi\\
journalctl ... /var/log/messages na SystemD (RH6, Fedora 20 atd)\\
journalctl --vacuum-time=10d ... vycisti logy (/var/log/journal), necha jen 10 dni logu\\
journalctl --vacuum-size=2G ... vycisti logy (/var/log/journal), necha jen 2 GB\\



====Napoveda, dokumentace====
export MANPATH=/usr/share/man ... nastavi cestu k MAN strankam\\
man -k disk ... vypise vsechny man stranky, kde je v popisu obsazen "disk"\\
nrofl -man [[manpage.txt|manpage.1]] ... zobrazi, jak bude manualova stranka vypadat\\
groff -man -Tascii page.txt ... zobrazi z ascii souboru manualovou stranku (jako nroff)\\
groff -man manpage.txt > file.ps ... vytvori post skiptovy soubor z manualove stranky\\
man2html -title 'Titulek' < Ascii_soubor.txt > html_soubor.html  ... prevede soubor s definici manualovych stranek do html\\


====Konzole - RSA====
[[http://en.wikipedia.org/wiki/IBM_Remote_Supervisor_Adapter|RSA]]\\
[[http://openipmi.sourceforge.net/|OpenIPM]] ... otevreny projekt k [[http://en.wikipedia.org/wiki/Intelligent_Platform_Management_Interface|IMPI]]\\
[[http://www-947.ibm.com/support/entry/portal/docdisplay?brand=5000008&lndocid=MIGR-55021|IBM Advanced Settings Utility (ASU)]] ... nastroj na konfiguraci RSA kartet na IBM xSeries\\