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Witold Duranek

więcej na: http://jesien.org/2013/pl/agenda

Zapraszam,

Lets assume that you have file image:

dd if=/dev/zero of=file.1 bs=4k count=128

on top of it you create filesystem ext3/ext4

mkfs.ext4 /root/file.1

mount it, create remove some files etc. and you gonna make it more space efficient, that's ...

Couple days ago I found out that memory usage grow rapidly on one server. After couple minutes of investigation, it was clear that memory balloon take place. Of course it will happen only if you have vmware tools installed. To find out what was happening, you can look at vmware ...

Make one step forward after rediscovering newly added hard disk, simply how to resize it. In virtual world simply put the new disk size, but how to reflect this change in guest operating system:

echo 1 > /sys/block/<devname>/device/rescan
partprobe

Continuing how to make them unavailable first to ...

Remote command execution from one host to another is nothing new in more complex infrastructure. It is usually going to happen at low user level privilege and it's also password less ssh communication based on ssh keys. But what happens when ssh keys leaked or this account was compromised ...

Using free VMware vSphere Hypervisor doesn't give us a chance to easily clone virtual machines disks and cope with thin provision disks. But we could leverage administration to CLI (shell) and there we have command called: vmkfstools. This command is used to manage virtual disks i.e. create, convert ...

Each time when you read file it's content is put into cache:

# grep -w "Cached" /proc/meminfo
Cached:           255220 kB
# cat sample.file >/dev/null
# grep -w "Cached" /proc/meminfo
Cached:           357628 kB

of course it happens when there is enough free memory. But imagine situation when you read ...

• replace default escape character (ctrl+shift+6) to ctrl+c:

line vty 0 4
  escape-character 3

• show logging timestamps in configured timezone

service timestamps log datetime localtime year

• secure your configuration

http://www.cisco.com/en/US/docs/ios/sec_user_services/configuration/guide/sec_autosecure.html

Easy way to find out if something changed since my last tar backup:

tar -df mylastbackup.tar.gz