อันนี้งานราษฎร์ครับ
ขอขอบคุณวิทยาทานจาก คุณต้นโพธิ์ ณ พันทิป ผู้เชี่ยวชาญระบบตัวจริง
ที่เขียนแผนผังการเชื่อมต่อระบบน้ำประปาสำหรับบ้านอยู่อาศัยไว้ตามรูป ขออนุญาตเก็บไว้เป็นข้อมูลอ้างอิงนะครับ (อาจจำเป็นต้องปรับปรุงระบบที่บ้านเร็วๆ นี้)
ที่มา: http://www.bloggang.com
คราวที่แล้ว ได้ทดสอบ pen ซึ่งเป็น opensource load balancer ในแง่ของ feature ก็รองรับความต้องการทั้ง http และ smtp เพียงแต่สิ่งที่ยังขาดก็คือ ไม่รองรับ ipv6 น่ะสิ
คราวนี้มาเจอ PLB (Pure Load Balancer) ซึ่งรองรับ IPv6 แต่กลับไม่รองรับ SMTP แต่ก็ไม่เป็นไร ยังไงก็ขอลองทดสอบกับ HTTP ดูก่อน ใน document บอกด้วยว่าประสิทธิภาพบน OS ตระกูล BSD จะดีกว่าบน Linux
ที่ยังขาดคือ freevrrpd ที่ดูเหมือนจะไม่ support ipv6 อาจจะต้องเปลี่ยนไปใช้ CARP (Common Address Redundancy Protocol) ไม่รู้ว่ามี package บน FreeBSD รึเปล่า (เพราะเป็น development บน OpenBSD)
อัพเดต: .. เพราะว่า ucarp ยังไม่รองรับ IPv6 เลยต้องใช้วิธีตามด้านล่างนี้ ..
- ใช้ ucarp บน FreeBSD Host 2 เครื่อง ทำหน้าที่เป็น Redundancy Load Balancer โดยใช้ up/down script ของ ucarp ช่วยโยก Virtual IPv6 ตามไปอยู่กับ Active Load Balancer
- ใช้ pen เป็น Load Balancer สำหรับ IPv4 HTTP และ SMTP
- ใช้ plb เป็น Load Balancer สำหรับ IPv6 ซึ่งทำได้เฉพาะ HTTP (ยังไม่รองรับ SMTP) แต่ Real server จะใช้เป็น IPv6 หรือ IPv4 ก็ได้
- ควบคุมให้ pen และ plb run เฉพาะบนเครื่องที่เป็น Active Load Balancer ด้วย up script และ down script ของ ucarp (Standby Load Balancer จะไม่ run pen และ plb)
ปล. เจอแล้ว plb กับ ucarp สำหรับ FreeBSD 6.2-RELEASE/sparc64
ช่วงนี้กำลังจำเป็นต้องใช้ filter ของ nfdump เพื่อทำการคัดกรอง traffic data จาก netflow เฉพาะที่สนใจ ซึ่งเป็นอันเดียวกับ tcpdump expression ข้างล่าง
TCPDUMP Expression
expression
selects which packets will be dumped. If no
expression is given, all packets on the net will be
dumped. Otherwise, only packets for which expression
is `true' will be dumped.
ber) preceded by one or more qualifiers. There are
three different kinds of qualifier:
type qualifiers say what kind of thing the id
name or number refers to. Possible types
are host, net and port. E.g., `host foo',
`net 128.3', `port 20'. If there is no type
qualifier, host is assumed.
dir qualifiers specify a particular transfer
direction to and/or from id. Possible
directions are src, dst, src or dst and src
and dst. E.g., `src foo', `dst net 128.3',
`src or dst port ftp-data'. If there is no
dir qualifier, src or dst is assumed. For
`null' link layers (i.e. point to point protocols
such as slip) the inbound and out�
bound qualifiers can be used to specify a
desired direction.
proto qualifiers restrict the match to a particular
protocol. Possible protos are: ether,
fddi, tr, ip, ip6, arp, rarp, decnet, tcp
and udp. E.g., `ether src foo', `arp net
128.3', `tcp port 21'. If there is no proto
qualifier, all protocols consistent with the
type are assumed. E.g., `src foo' means
`(ip or arp or rarp) src foo' (except the
latter is not legal syntax), `net bar' means
`(ip or arp or rarp) net bar' and `port 53'
means `(tcp or udp) port 53'.
[`fddi' is actually an alias for `ether'; the
parser treats them identically as meaning ``the
data link level used on the specified network
interface.'' FDDI headers contain Ethernet-like
source and destination addresses, and often contain
Ethernet-like packet types, so you can filter on
these FDDI fields just as with the analogous Ether�
net fields. FDDI headers also contain other
fields, but you cannot name them explicitly in a
filter expression.
Similarly, `tr' is an alias for `ether'; the previous
paragraph's statements about FDDI headers also
apply to Token Ring headers.]
In addition to the above, there are some special
`primitive' keywords that don't follow the pattern:
gateway, broadcast, less, greater and arithmetic
expressions. All of these are described below.
tives. E.g., `host foo and not port ftp and not
port ftp-data'. To save typing, identical qualifier
lists can be omitted. E.g., `tcp dst port ftp
or ftp-data or domain' is exactly the same as `tcp
dst port ftp or tcp dst port ftp-data or tcp dst
port domain'.
Allowable primitives are:
dst host host
True if the IPv4/v6 destination field of the
packet is host, which may be either an
address or a name.
src host host
True if the IPv4/v6 source field of the
packet is host.
host host
True if either the IPv4/v6 source or destination
of the packet is host. Any of the
above host expressions can be prepended with
the keywords, ip, arp, rarp, or ip6 as in:
ip host host
which is equivalent to:
ether proto \ip and host host
If host is a name with multiple IP
addresses, each address will be checked for
a match.
ether dst ehost
True if the ethernet destination address is
ehost. Ehost may be either a name from
/etc/ethers or a number (see ethers(3N) for
numeric format).
ether src ehost
True if the ethernet source address is
ehost.
ether host ehost
True if either the ethernet source or destination
address is ehost.
gateway host
True if the packet used host as a gateway.
I.e., the ethernet source or destination
address was host but neither the IP source
nor the IP destination was host. Host must
be a name and must be found both by the
machine's host-name-to-IP-address resolution
mechanisms (host name file, DNS, NIS, etc.)
etc.). (An equivalent expression is
ether host ehost and not host host
which can be used with either names or numbers
for host / ehost.) This syntax does
not work in IPv6-enabled configuration at
this moment.
dst net net
True if the IPv4/v6 destination address of
the packet has a network number of net. Net
may be either a name from /etc/networks or a
network number (see networks(4) for
details).
src net net
True if the IPv4/v6 source address of the
packet has a network number of net.
net net
True if either the IPv4/v6 source or desti�
nation address of the packet has a network
number of net.
net net mask netmask
True if the IP address matches net with the
specific netmask. May be qualified with src
or dst. Note that this syntax is not valid
for IPv6 net.
net net/len
True if the IPv4/v6 address matches net with
a netmask len bits wide. May be qualified
with src or dst.
dst port port
True if the packet is ip/tcp, ip/udp,
ip6/tcp or ip6/udp and has a destination
port value of port. The port can be a number
or a name used in /etc/services (see
tcp(4P) and udp(4P)). If a name is used,
both the port number and protocol are
checked. If a number or ambiguous name is
used, only the port number is checked (e.g.,
dst port 513 will print both tcp/login
traffic and udp/who traffic, and port domain
will print both tcp/domain and udp/domain
traffic).
src port port
True if the packet has a source port value
of port.
True if either the source or destination
port of the packet is port. Any of the
above port expressions can be prepended with
the keywords, tcp or udp, as in:
tcp src port port
which matches only tcp packets whose source
port is port.
less length
True if the packet has a length less than or
equal to length. This is equivalent to:
len <= length.
greater length
True if the packet has a length greater than
or equal to length. This is equivalent to:
len >= length.
ip proto protocol
True if the packet is an IP packet (see
ip(4P)) of protocol type protocol. Protocol
can be a number or one of the names icmp,
icmp6, igmp, igrp, pim, ah, esp, vrrp, udp,
or tcp. Note that the identifiers tcp, udp,
and icmp are also keywords and must be
escaped via backslash (\), which is \\ in
the C-shell. Note that this primitive does
not chase the protocol header chain.
ip6 proto protocol
True if the packet is an IPv6 packet of protocol
tocol type protocol. Note that this primitive
does not chase the protocol header
chain.
ip6 protochain protocol
true if the packet is IPv6 packet, and contains
protocol header with type protocol in
its protocol header chain. For example,
ip6 protochain 6
matches any IPv6 packet with TCP protocol
header in the protocol header chain. The
packet may contain, for example, authentication
header, routing header, or hop-by-hop
option header, between IPv6 header and TCP
header. The BPF code emitted by this primitive
is complex and cannot be optimized by
BPF optimizer code in tcpdump, so this can
be somewhat slow.
ip protochain protocol
Equivalent to ip6 protochain protocol, but
True if the packet is an ethernet broadcast
packet. The ether keyword is optional.
ip broadcast
True if the packet is an IP broadcast
packet. It checks for both the all-zeroes
and all-ones broadcast conventions, and
looks up the local subnet mask.
ether multicast
True if the packet is an ethernet multicast
packet. The ether keyword is optional.
This is shorthand for `ether[0] & 1 != 0'.
ip multicast
True if the packet is an IP multicast
packet.
ip6 multicast
True if the packet is an IPv6 multicast
packet.
ether proto protocol
True if the packet is of ether type protocol.
Protocol can be a number or one of the
names ip, ip6, arp, rarp, atalk, aarp, dec�
net, sca, lat, mopdl, moprc, iso, stp, ipx,
or netbeui. Note these identifiers are also
keywords and must be escaped via backslash
(\).
[In the case of FDDI (e.g., `fddi protocol
arp') and Token Ring (e.g., `tr protocol
arp'), for most of those protocols, the protocol
identification comes from the 802.2
Logical Link Control (LLC) header, which is
usually layered on top of the FDDI or Token
Ring header.
When filtering for most protocol identifiers
on FDDI or Token Ring, tcpdump checks only
the protocol ID field of an LLC header in
so-called SNAP format with an Organizational
Unit Identifier (OUI) of 0x000000, for
encapsulated Ethernet; it doesn't check
whether the packet is in SNAP format with an
OUI of 0x000000.
The exceptions are iso, for which it checks
the DSAP (Destination Service Access Point)
and SSAP (Source Service Access Point)
fields of the LLC header, stp and netbeui,
packet with an OUI of 0x080007 and the
Appletalk etype.
In the case of Ethernet, tcpdump checks the
Ethernet type field for most of those proto�
cols; the exceptions are iso, sap, and net�
beui, for which it checks for an 802.3 frame
and then checks the LLC header as it does
for FDDI and Token Ring, atalk, where it
checks both for the Appletalk etype in an
Ethernet frame and for a SNAP-format packet
as it does for FDDI and Token Ring, aarp,
where it checks for the Appletalk ARP etype
in either an Ethernet frame or an 802.2 SNAP
frame with an OUI of 0x000000, and ipx,
where it checks for the IPX etype in an Ethernet
frame, the IPX DSAP in the LLC header,
the 802.3 with no LLC header encapsulation
of IPX, and the IPX etype in a SNAP frame.]
decnet src host
True if the DECNET source address is host,
which may be an address of the form
``10.123'', or a DECNET host name. [DECNET
host name support is only available on
Ultrix systems that are configured to run
DECNET.]
decnet dst host
True if the DECNET destination address is
host.
decnet host host
True if either the DECNET source or destination
address is host.
ip, ip6, arp, rarp, atalk, aarp, decnet, iso, stp,
ipx, netbeui
Abbreviations for:
ether proto p
where p is one of the above protocols.
lat, moprc, mopdl
Abbreviations for:
ether proto p
where p is one of the above protocols. Note
that tcpdump does not currently know how to
parse these protocols.
vlan [vlan_id]
True if the packet is an IEEE 802.1Q VLAN
packet. If [vlan_id] is specified, only
encountered in expression changes the decoding
offsets for the remainder of expression
on the assumption that the packet is a VLAN
packet.
tcp, udp, icmp
Abbreviations for:
ip proto p or ip6 proto p
where p is one of the above protocols.
iso proto protocol
True if the packet is an OSI packet of protocol
type protocol. Protocol can be a number
or one of the names clnp, esis, or isis.
clnp, esis, isis
Abbreviations for:
iso proto p
where p is one of the above protocols. Note
that tcpdump does an incomplete job of parsing
these protocols.
expr relop expr
True if the relation holds, where relop is
one of >, <, >=, <=, =, !=, and expr is an
arithmetic expression composed of integer
constants (expressed in standard C syntax),
the normal binary operators [+, -, *, /, &,
|], a length operator, and special packet
data accessors. To access data inside the
packet, use the following syntax:
proto [ expr : size ]
Proto is one of ether, fddi, tr, ip, arp,
rarp, tcp, udp, icmp or ip6, and indicates
the protocol layer for the index operation.
Note that tcp, udp and other upper-layer
protocol types only apply to IPv4, not IPv6
(this will be fixed in the future). The
byte offset, relative to the indicated protocol
layer, is given by expr. Size is
optional and indicates the number of bytes
in the field of interest; it can be either
one, two, or four, and defaults to one. The
length operator, indicated by the keyword
len, gives the length of the packet.
For example, `ether[0] & 1 != 0' catches all
multicast traffic. The expression `ip[0] &
0xf != 5' catches all IP packets with
options. The expression `ip[6:2] & 0x1fff =
0' catches only unfragmented datagrams and
frag zero of fragmented datagrams. This
always means the first byte of the TCP
header, and never means the first byte of an
intervening fragment.
Some offsets and field values may be
expressed as names rather than as numeric
values. The following protocol header field
offsets are available: icmptype (ICMP type
field), icmpcode (ICMP code field), and
tcpflags (TCP flags field).
The following ICMP type field values are
available: icmp-echoreply, icmp-unreach,
icmp-sourcequench, icmp-redirect, icmp-echo,
icmp-routeradvert, icmp-routersolicit, icmp-
timxceed, icmp-paramprob, icmp-tstamp, icmp-
tstampreply, icmp-ireq, icmp-ireqreply,
icmp-maskreq, icmp-maskreply.
The following TCP flags field values are
available: tcp-fin, tcp-syn, tcp-rst, tcp-
push, tcp-push, tcp-ack, tcp-urg.
Primitives may be combined using:
A parenthesized group of primitives and
operators (parentheses are special to the
Shell and must be escaped).
Negation (`!' or `not').
Concatenation (`&&' or `and').
Alternation (`||' or `or').
Negation has highest precedence. Alternation and
concatenation have equal precedence and associate
left to right. Note that explicit and tokens, not
juxtaposition, are now required for concatenation.
If an identifier is given without a keyword, the
most recent keyword is assumed. For example,
not host vs and ace
is short for
not host vs and host ace
which should not be confused with
not ( host vs or ace )
Expression arguments can be passed to tcpdump as
either a single argument or as multiple arguments,
whichever is more convenient. Generally, if the
expression contains Shell metacharacters, it is
before being parsed.EXAMPLES
To print all packets arriving at or departing from sun�
down:
tcpdump host sundown
To print traffic between helios and either hot or ace:
tcpdump host helios and \( hot or ace \)
To print all IP packets between ace and any host except
helios:
tcpdump ip host ace and not helios
To print all traffic between local hosts and hosts at
Berkeley:
tcpdump net ucb-ether
To print all ftp traffic through internet gateway snup:
(note that the expression is quoted to prevent the shell
from (mis-)interpreting the parentheses):
tcpdump 'gateway snup and (port ftp or ftp-data)'
To print traffic neither sourced from nor destined for
local hosts (if you gateway to one other net, this stuff
should never make it onto your local net).
tcpdump ip and not net localnet
To print the start and end packets (the SYN and FIN pack�
ets) of each TCP conversation that involves a non-local
host.
tcpdump 'tcp[tcpflags] & (tcp-syn|tcp-fin) != 0
and not src and dst net localnet'
To print IP packets longer than 576 bytes sent through
gateway snup:
tcpdump 'gateway snup and
ip[2:2] > 576'
To print IP broadcast or multicast packets that were not
sent via ethernet broadcast or multicast:
tcpdump 'ether[0] & 1 = 0 and
ip[16] >= 224'
To print all ICMP packets that are not echo
requests/replies (i.e., not ping packets):
tcpdump 'icmp[icmptype] != icmp-echo and
icmp[icmptype] != icmp-echoreply'
ที่มา: http://www.tcpdump.org
เร็วๆ นี้ได้คุยกันกับน้องๆ ในทีมที่ทำงาน ล่าสุด มีความเห็นตรงกัน(นานแล้วล่ะ)ว่า ต้องหาวิธีบริหารจัดการงาน ที่ปัจจุบันทำกันอย่างไม่มีระบบ ด้วยความจริงจังซักทีนึง แต่ด้วยความที่ไม่ใช่ทางของเรามาก่อน ก็เลยอาจจะเป็นเรื่องยากซักหน่อย ประมาณว่าทำเองคงไม่สำเร็จ คงต้องให้น้องๆ (มันเป็นทางของพวกเค้า)เป็น leader ให้ ส่วนตัวเราเองก็คอยหาข้อมูล เรียนรู้ ทุกวัน และสำคัญที่สุด คอยสนับสนุนอย่างเต็มที่เต็มกำลัง
งานหลักของทีมเป็นเรื่อง Software Development ซะส่วนใหญ่ ปัญหาในปัจจุบันคือ หนึ่ง งานเสร็จไม่ทันเวลา ทำให้ธุรกิจได้รับผลกระทบ สอง บางครั้งงานเสร็จทัน (ด้วยความกดดันในเรื่องธุรกิจ) แต่ขาดคุณภาพ ทำให้ในระยะยาวปัญหาเกิดตามมามากมาย ถ้าใครบังเอิญมาได้อ่านบล็อกนี้ แล้วมีคำแนะนำ ผมยินดีนะครับ และก็ขอบคุณล่วงหน้ามา ณ ที่นี้ด้วยเลย
ส่วนตัวต้องมาศึกษาเรื่องนี้ให้มากๆ และจริงจัง (เพราะเคยลองแต่อ่านแล้วไม่รู้เรื่อง ก็เลิกราไปก่อน) และก็ตาม concept ของ TechNo! คือ บันทึกแหล่งข้อมูลไว้ก่อน
ปล. ตอนนี้ผมใช้ Bookmark ของ ma.golia อยู่ด้วย
ข้อกำหนดของ พ.ร.บ. การกระทำความผิดเกี่ยวกับคอมพิวเตอร์ ทำให้ต้องหาวิธีทางที่จะ backup traffic data (log file) เรามองกันที่ rsync ว่าน่าจะเหมาะที่สุด เห็นฝรั่งเขารวบรวม backup tools ที่ใช้ rsync ไว้ให้ เลยขออนุญาตคัดลอกไว้ที่นี่
1. rsync-incr - a Linux wrapper shell (bash) script around rsync to perform automated, unattended, incremental, disk to disk backups, automatically removing old backups to make room for new ones. It produces standard mirror copies that are browsable and restorable without specific tools.
2. RSync Manager - a set of Python scripts to add and update packages for rsync-based mirror sites, and also create some nice HTML statistics from the logs. It is mainly written for large site management, with extensibility in mind.
3. Warsync - server replication system mainly used to sync servers in LVS clusters. It is based on rsync over ssh and has native support for Debian package synchronization.
4. Rsync Vault Manager - an archive manager that uses rsync to manage backups of multiple clients across multiple logical partitions.
5. Rsync Incremental Backup Script - an incremental backup system written using PHP, rsync, ssh, and cp. It can backup local machines and other networked devices, and is designed to be highly configurable and informative for system administrators. It performs a large amount of error checking, and includes logging and email capabilities.
6. Grsync - a GUI for rsync, the command line directory synchronization tool. While it can work with remote hosts, its focus is to synchronize local directories.
7. Rsyncrypto - allows you to encrypt a file or a directory structure such that they can later be synchronized to another machine using rsync.
8. Rsyncbackup - a handy tool for scheduled backups using rsync. rsyncbackup lets you easily setup multiple source folders and destinations, both locally, on your iPod or external firewire disk, or at a remote destination using ssh.
9. Rsync-backup - automates the process of backing up multiple systems to one or more backup servers. It focuses on making the process secure. It encrypts the backup going across the wire, only ships changed data, runs the server as root to preserve permissions and ownership, keeps people from seeing each other’s backups, and doesn’t require the server to trust any files sent from the clients.
10. Backup Buddy - a set of scripts which make versioned, disk-to-disk, backups via rsync easy. It allows the user to set up disk-to-disk backups that happen automatically.
11. Zsync - an implementation of rsync over HTTP. It allows updating of files from a remote Web server without requiring a full download or a special remote server application.
12. NasBackup - a solution for backing up desktop PCs, laptops, and servers to network disks. It is highly configurable and uses rsync to only transfer file differences over the network.
13. Rsnapshot - a filesystem snapshot utility based on rsync. It makes it easy to make periodic snapshots of local machines, and remote machines over ssh. It uses hard links whenever possible, to greatly reduce the disk space required.
14. OtheRSync - a program for the automatic, efficient, and safe synchronization of two machines over a network. It’s efficient (using compression and incremental changes), safe (uses ssh, is fail-safe, and makes backups of deleted files by default), uses parallel processing, and supports feedback through the commandline prompt.
15. Rsynchelper - helps you use the mirroring program rsync. rsynchelper makes it easier for groups of servers to cooperate in mirroring. rsynchelper makes it easier to make your content available for others to mirror, makes it easier to mirror someone else’s content, and it automates the maintenance of an accurate list of who is maintaining which content.
ที่มา: http://blog.lxpages.com/2007/06/28/rsync-backup-solutions/
Robin Harris รวบรวม Link ของ Video จากงาน Seattle Conference of Scalability ไว้ที่ StorageMojo ครับ
- Building a Scalable Resource Mgmt System for Grid Computing (Khalid Ahmed, Platform Computing)
- Lustre File System (Peter Braam, Cluster File Systems)
- Abstractions for Handling Large Datasets (Jeff Dean, Google)
- Scalable Test Selection Using Source Code Deltas (Ryan Gerard, Symantec Corporation)
- Lessons In Building Scalable Systems (Reza Behforooz, Google)
- Using MapReduce on Large Geographic Datasets (Barry Brumitt, Google)
- YouTube Scalability (Cuong Do Cuong, Youtube)
- Scaling Google for Every User (Marissa Mayer, Google)
- SCTPs Reliability and Fault Tolerance (Brad Penoff, Mike Tsai, Alan Wagner, UBC)
- VeriSign’s Global DNS Infrastructure (Scott Courtney, Pat Quaid, VeriSign)
ที่มา: http://storagemojo.com
The Untangle Gateway Platform is a commercial-grade open source solution for blocking spam, spyware, viruses, adware and unwanted content on the network, setting up secure remote access and more. Check out all 14 network applications available today for free.
Product Overview
Small Storage Solutions
Posted In:
storage
.
By taladnam
Storage Solutions ขนาดเล็ก ราคาเริ่มต้นที่ประมาณ 1-2 แสน
- Coraid :: The Linux Storage People - EtherDrive...
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