Knowledge Base

OpenVZ

• problem s IPTABLES - conntrack od vzctl 4.7

KVM/Libvirt

• How to online resize KVM disk
• How to online attach KVM disk
• Creating QCOW2 overlay on top of read-only device

Cluster

• Setting VPS IO limits
• Shared OCFS file system between VPSs?
• Rename a non-clustered LVM on cluster
• Create OCFS2 partition
• How to resolve clvmd pvmove deadlock
• Oprava rozpadleho DRBD
• Instalace a nastaveni clusteru
• Rescan SCST target on initiator
• LVM locking failed on volume resize

Linux

• Manually create md RAID on CentOS/Scientific Linux
• Resize md RAID 0 after underlying disk grew in size
• EnhanceIO settings
• Discard,Trim,Unmap
• Resize tmpfs online
• Create luks encrypted partition
• Fix MC line-drawing issues in Putty
• Creating a simple CA cert and signed server cert
• Localization of bad RAM DIMM
• edit PROMPT
• Setting sssd authentication
• Use of UVT LXR Cross Referencer
• Transform Scientfic Linux 6 to CentOS 6
• Instalace Let's Encrypt klienta
• How to build RPM using our system
• EnhanceIO settings
• PageCache tuning
• Centralni sprava certifikatu podepsanych Let's Encrypt autoritou
• cos7-server
• Enable Ext4 Lazy Initialization
• Presun instalace COS7 na jiny stroj
• Pridani vyjimky do Java security
• LDAP vymena certifikatu pres cmd

MySQL

• Query mass kill
• Replication consistency check
• Replication consistency check and repair
• Create mysql replication
• MariaDB 10 example my.cnf
• MariaDB 10 - GTID based replication
• MariaDB 10 - multiinstance
• MySQL - repair corrupted relay log
• Mysql - how to debug problem with ROW based logging
• MariaBackup - how to restore

MongoDB

• Restore Single Mongo Collection

PostgreSQL

• Shared memory problem

DRBD

• Stacked drbd in p-p environment
• Resume IO if fencing fails

Hardware

• ipmitool set dedicated lan
• Kalibrace APC UPS pres APCfix
• Setup Supermicro serial console
• Setup HPA on SSD
• Howto update firmware on mellanox IB card

Mikrotik

• Mikrotik ipsec SPI mismatch with multiple subnets
• How to setup backup for MT
• Unifi controller DHCP option

SCST

• Online extension of iscsi target
• FC & iSCSI target operations
• RW & RO target for different IQN
• Single initiator to multiple security group

Switche

• HP Procurve EAP auth debugging
• Huawei Quidway EasyDeploy
• Huawei restore config and update fw

SSL Certificates Providers

• SSL Certificates Providers

Infiniband

• Infiniband basics

Areca

• Areca RS/VS expansion by changing disks
• areca restart without restart server
• Re-activate failed disk

PHP

• eBrana - php56.ini
• eBrana - php memory limit not working

FreeBSD

• FreeBSD 9.1 - virtio
• FreeBSD 9.1 - setup
• FreeBSD 9.1 - disk growing

Benchmarks

• FIO

Nginx

• internal URL rewrite

Systemd

• Syslog not working
• NSpawn howto

Backups/Restores

• Restore virus encrypted files on Samba from BackupPC
• BackupPC restore from command-line
• Attach drbd iscsi backup to array

Security

• Openvas security scanner

Brno Iprace

• Fix Crawler Crash on KeyError

Elasticsearch

• API calls to debug failures

Unifi

• Best practices

Mattermost Chat

• Creating new team and users