Play with Boost::Any
Motivation: When I read: ./linux/types.h , there is comment saying that: aligned u64 should be used in defining kernel<->userspace ABIs to avoid common 332/64-bit comapt problems. What is ABI: It stands for Application Binary Interface. AB…
memory_resource
What I want to know is not how to install, use or whatever. I just want to know how it works. Understanding jemallo
Neutron ML2 The Modular Layer2 (ml2) plugin is a framework allowing OpenStack Networking to simultaneusly utilze the variety of layer2 networking technology found in complex real-world data centres. It currently works with the existing ope…
It's good starting point where you completely and perfectly understand how Ceph works. This page will be update soon to put more perfect explanation coming from more analisys. /* * Operation started. */#./src/osd/OSD.cc5676 bool OSD::dispa…
Notice: This series is to expect to use kernel 3.10.0-229. 1.What Cinder provides. It provides block storage which allows block devices to be exposed and connected to compute instances for expanded storage, better performance and integrati…
Everything is defined in: /usr/lib/systemd/system/ and in: Bootstrap of systemd at the boot timedocs.google.com
In the field of computer network administration, pcap (packet capture) consists of an application programming interface (API) for capturing network traffic. Unix-like systems implement pcap in the libpcap library; Windows uses a port of li…
Notice: This series is to expect to use kernel 3.10.0-229. 1. What Glance provides. It provides a catalog service for storing and querying virtual disk images. Glance also provides an end-to-end solution for cloud disk image management wit…
This was quite interesting to me. irb(main):001:0> me1 = "puts 'Life with Linux'"=> "Life with Linux" irb(main):002:0> puts me1puts 'Life with Linux'=> nil irb(main):003:0> eval me1Life with Linux=> nil irb(main):004:0> bytes_in_binary1 = …
Notice: This series is to expect to use kernel 3.10.0-229. 1. What Swift provides is A massively scalable and redundant object store conceptually similar to Amazon S3. S3: Simple Storage Service To provide this scalability and redundancy, …
Notice: Descriptions of LAYER in this document are based on the OSI model. Layer5 Three system calls: write sendto sendmsg end up in: __sock_sendmsg() which does: security_sock_sendmsg() to check prmissions, then forwards the message to th…
Notice: This series is to expect to use kernel 3.10.0-229. Keystone, what does it do , and how it works. 1. Introduction Keystone provides identity and access policy services for all components in the OpenStack family. It implements it's o…
Notice: This series is to expect to use kernel 3.10.0-229. These days, It's getting easier to build OpenStack infrastructure because so many contributors have been struggling with, working for OpenStack. In this series, I will write not on…
■ Working with Git To start working with Git, you just need to run ""git init" command. It turns the current directory into the Git working directory and creates the repository in the .git (hidden) directory created there. * git init: To i…
The realloc() function changes the size of the memory block pointed to by ptr to size bytes. void* realloc(void* oldmem, size_t bytes) The contents will be unchanged in the range from the start of the region up to the minimum of the old an…
Suddenly autofs stop working from time time. Here is an error message in syslog on ldap client. Feb 3 11:14:58 <hostname> automount[2462]: __init_ldap_connection: lookup(ldap): TLS required but START_TLS failed: Can't contact LDAP server __init_ldap</hostname>…
demidecode --type: 0: BIOS 1: System 2: Base Board 3: Chassis 4: Processor 5: Memory Controller 6: Memory Module 7: Cache 8: Port Connector 9: System Slots 10: On Board Devices 11: OEM Strings 12: System Configuration Options 13: BIOS Lang…
RHEL6.5では、カーネルと同じリビジョンの kernel-debuginfo と kernel-debuginfo-common を、debuginfo-install でインストールするだけで、stap が機能したけど、RHEL7 では、上手くいかない。 RHEL6.5 [root@x201s ~]# rpm -qa | grep debugkernel-debugi…
The queues on the transmit path of the linux kernel 1. IP Stack -> Queueing Discipline -> Driver Queue -> NIC 2. Driver Queue [ | | | | | | | | | | | | | | | | SKB | SKB | SKB | SKB | ] 3. SKB: Socket kernel buffer [ The packet data ] Most…
1. To know if Firewalld is runnng. $ systemctl status firewalld or $ firewall-cmd --state * もし、IPv4のネットワークが、同一ホストの複数のインタフェースで、使用されているのであれば、フォワーディングの設定が必要になる。 $ cat /etc/sysctl.co…
ボトルネック調査について 分散ファイルシステムでのボトルネック調査は、困難になることが多々ある。 デバッグのためのプロセス 1. サーバ、クライアント側での確認 - OSS、MDSサーバ側での負荷 - どのサーバで、過剰な負荷が発生しているか - どの操作が、…
とりあえず、理解したいので。 http://golang.org/pkg/net/http/httputil/ を読みながら、基本的なことをメモ 仮想マシンで echo コマンドを実行 $ docker run centos /bin/echo test 仮想マシンにログイン $ docker run -i -t centos /bin/bash 仮想マシン…
[root@localhost docker]# date Sun Dec 21 05:26:04 EST 2014 コード [root@localhost docker]# cat **/*.go | wc -l38383 本体 [root@localhost docker]# cat $(ls **/*.go | grep -vi test.go) | wc -l18410 テスト [root@localhost docker]# cat $(ls **…
容量 最大 8EiB (32bits linux: 16TiB) ジャーナリング ファイルシステムへの変更が発生した場合は、直列化されたジャーナルに書き込まれたあと、実ブロックの更新が行われる。 書き込み操作が発生すると、 1. オペレーションのログとしてメタ・データの更新…
GlusterFS CTDB Integration from Etsuji Nakai
http://techarena51.com/index.php/build-rpm-without-breaking-head/
To display information about available block devices blkid For each listed block device, the blkid command displays available attributes such as its universally unique identifier(UUID), file system type(TYPE), or volume label (LABEL). You …
