1. crop pdf files
pdfcrop --margins '-30 -30 -10 -20' input.pdf output.odf
margins: left, top, right, bottom
2.
string="this is a string" tmpfile=$(mktemp) && echo $string | \ enscript -M a4 --margins=::0: -B -f Courier-Bold8 -o- | \ ps2pdf - "$tmpfile" && \ qpdf input.pdf --overlay "$tmpfile" -- output.pdf && \ rm -f "$tmpfile"
enscript --margins=left:right:top:bottom
#enable remote access (mind also the firewall)
# provides UDP syslog reception module(load="imudp") input(type="imudp" port="514") # provides TCP syslog reception module(load="imtcp") input(type="imtcp" port="514")
#redirect all expernal traffic to dedicated file
$template remote-incoming-logs,"/var/log/remote/%HOSTNAME%.log" :inputname, isequal, "imudp" ?remote-incoming-logs :fromhost-ip , !isequal , "127.0.0.1" stop
Further reading: here
The original LV named data/bigdata consists of two separate drives: /dev/sdc1 (6T) and /dev/sdd1 (5T) .
I would like to replace these two disks by the 12T single drive (/dev/sde).
The standard way is using the pvmove commnad. However, I opted to use mirroring approach.
pvcreate /dev/sde1
vgextend data /dev/sde1
lvconvert --type mirror -m 1 /dev/data/bigdata
lvs -a -o name,copy_percent,devices data
lvs --all --segments -o +devices
Now there is 1PE free space between two segments on /dev/sde1
[root@server ~]# pvs --segments -v PV VG Fmt Attr PSize PFree Start SSize LV Start Type PE Ranges /dev/sdc1 data lvm2 a-- <5.46t <5.46t 0 1430791 0 free /dev/sdd1 data lvm2 a-- <4.55t <4.55t 0 1192326 0 free /dev/sde1 data lvm2 a-- 10.91t <5.46t 0 1430791 bigdata 0 linear /dev/sde1:0-1430790 /dev/sde1 data lvm2 a-- 10.91t <5.46t 1430791 1 0 free /dev/sde1 data lvm2 a-- 10.91t <5.46t 1430792 1192326 bigdata 0 linear /dev/sde1:1430792-2623117
to remove the free space, move the second segment from /dev/sde1 to the old drive, and than back to /dev/sde1
pvmove /dev/sde1:1430792-2623117 /dev/sdc1 pvmove /dev/sdc1 /dev/sde1
[root@server ~]# pvs --segments -v PV VG Fmt Attr PSize PFree Start SSize LV Start Type PE Ranges /dev/sdc1 data lvm2 a-- <5.46t <5.46t 0 1430791 0 free /dev/sdd1 data lvm2 a-- <4.55t <4.55t 0 1192326 0 free /dev/sde1 data lvm2 a-- 10.91t <929.45g 0 2623117 bigdata 0 linear /dev/sde1:0-2623116 /dev/sde1 data lvm2 a-- 10.91t <929.45g 2623117 237938 0 free
This way the two segments join without further conditions.
pvdisplay -m /dev/sde1
lvs --all --segments -o +devices data
lvs -a -o name,copy_percent,devices datapvs --segments -v
/dev/sdd
Number Start (sector) End (sector) Size Code Name
1 2048 11721045134 5.5 TiB FD00 Linux RAID
truncate -s $(((11721045134-2048)*512)) fake-sdd1-file losetup -f fake-sdd1-filereplace the failing drive with the virtual spare space
mdadm --manage /dev/md0 --add /dev/loop0 mdadm /dev/md0 --replace /dev/sdd1 --with /dev/loop0wait for data replication (see /proc/mdstat), then remove the failed drive
mdadm /dev/md0 --remove /dev/sdd1eventually, destroy all md data from the drive and delete the partition
mdadm --zero-superblock /dev/sdd1 gdisk /dev/sddor use
wipefs
Short:
First: identify and delete the old drive (identify HCTL, which is Host:Channel:Target:Lun (viz ))
$ lsscsi
[0:0:0:0] cd/dvd HL-DT-ST BD-RE BH10LS30 1.02 /dev/sr0 [1:0:0:0] disk ATA APPLE SSD TS256C 0201 /dev/sdd [2:0:0:0] disk ATA WDC WD6002FRYZ-0 1M03 /dev/sdb [3:0:0:0] disk ATA WDC WD5001F9YZ-0 1E03 /dev/sdc [N:0:1:1] disk WDC PC SN520 SDAPNUW-512G-1002__1 /dev/nvme0n1
$ lsscsi -g
[0:0:0:0] cd/dvd HL-DT-ST BD-RE BH10LS30 1.02 /dev/sr0 /dev/sg0 [1:0:0:0] disk ATA APPLE SSD TS256C 0201 /dev/sdd /dev/sg1 [2:0:0:0] disk ATA WDC WD6002FRYZ-0 1M03 /dev/sdb /dev/sg2 [3:0:0:0] disk ATA WDC WD5001F9YZ-0 1E03 /dev/sdc /dev/sg3 [N:0:1:1] disk WDC PC SN520 SDAPNUW-512G-1002__1 /dev/nvme0n1 -
$ lsblk -o NAME,MODEL,HCTL
NAME MODEL HCTL sdb WDC WD6002FRYZ-01WD5B1 2:0:0:0 └─sdb1 └─data-bigdata sdc WDC WD5001F9YZ-09YUWL1 3:0:0:0 └─sdc1 └─data-bigdata sdd APPLE SSD TS256C 1:0:0:0 sr0 HL-DT-ST BD-RE BH10LS30 0:0:0:0
and also:
readlink /sys/block/sdX
To find the physical SATA port number, add one to the given host number.
2:0:0:0 -> H=2, sdb == ata3
Or use this command:
# find -L /sys/bus/pci/devices/*/ata*/host*/target* -maxdepth 3 -name "sd*" 2>/dev/null |\ egrep block |egrep --colour '(ata[0-9]*)|(sd.*)'
/sys/bus/pci/devices/0000:00:18.0/ata1/host0/target0:0:0/0:0:0:0/block/sda /sys/bus/pci/devices/0000:00:18.0/ata2/host1/target1:0:0/1:0:0:0/block/sdb /sys/bus/pci/devices/0000:00:18.0/ata3/host2/target2:0:0/2:0:0:0/block/sdc ...
As a first step, the old drive has to be deleted (see), and (see):
echo 1 > /sys/block/sda/device/delete
Then rescan the host bus:
echo "- - -" >/sys/class/scsi_host/host<n>/scan
or
for i in /sys/class/scsi_host/host* ; do echo "- - -" > $i/scan ; done
(pred systemctl restart networking je obcas nutne rucne smazat IP adresy zarizeni, jinak se zmeny v /etc/network/interfaces neprojevi)
(podle https://blog.wijman.net/enable-rc-local-in-debian-bullseye/ )
Create a file /etc/rc.local
#!/bin/sh # ... # By default this script does nothing. /etc/rc.firewall touch /var/lock/subsys/local exit 0
chmod +x /etc/rc.local
Then we need to reload the systemd manager configuration:
systemctl daemon-reload
Then we start the rc-local daemon:
systemctl start rc-local
And then we check the status of rc-local to confirm it ran OK:
systemctl status rc-local Pokud definice sluzby chybi: (podle https://www.cyberciti.biz/faq/how-to-enable-rc-local-shell-script-on-systemd-while-booting-linux-system/ )
[Unit] Description=/etc/rc.local ConditionPathExists=/etc/rc.local [Service] Type=forking ExecStart=/etc/rc.local start TimeoutSec=0 StandardOutput=tty RemainAfterExit=yes SysVStartPriority=99 [Install] WantedBy=multi-user.target
anebo delsi a ukecanejsi soubor (ale musi mit sekci [Install]):
# /etc/systemd/system/rc-local.service
# SPDX-License-Identifier: LGPL-2.1+
#
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
# This unit gets pulled automatically into multi-user.target by
# systemd-rc-local-generator if /etc/rc.local is executable.
[Unit]
Description=/etc/rc.local Compatibility
Documentation=man:systemd-rc-local-generator(8)
ConditionFileIsExecutable=/etc/rc.local
After=network.target
[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
RemainAfterExit=yes
GuessMainPID=no
StandardOutput=journal+console
StandardError=journal+console
[Install]
WantedBy=multi-user.target[Install]
WantedBy=multi-user.target
iptables negate: (https://www.cyberciti.biz/faq/iptables-invert-ip-or-protocol-with/)
Narozdil od starsi implementace, negace se dava pred "option" (viz man iptables): --option ! this is deprecated in favour of ! --option this
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