Reading FTP Logs in xferlog Format

For some reason I can never remember the xferlog format that is used by daemons such as Pure-FTP. Although xferlog is well documented, I am always fumbling to find the doc when I need it, and it's never bad to have information duplicated in many places!

Anyways, on with the description. Here is a sample log entry from my server (with access IPs and dirs changed):

Fri May 14 05:16:12 2010 0 ::ffff:1.2.3.4 11974 /home/user/public_html/index.php a _ i r user ftp 0 * c

I'll step through each item individually. The delimiter here is whitespace, so each new token represents a unique piece of data, with the exception of the date at the beginning.

Fri May 14 05:16:12 2010
Date/time stamp, nothing complicated.

0
Transfer time, in whole seconds (this transfer took less than a second, so zero).

::ffff:1.2.3.4
Remote host where the user connected from.

11974
Size of the transferred file (in bytes).

/home/user/public_html/index.php
Full path to the uploaded file.

a
Transfer type, a = ASCII (plain-text files), b = binary (everything else)

_
Action flag, C = compressed, U = uncompressed; T = tar'ed; _ = no action was taken.

i
Direction, i = incoming, o = outgoing, d = deleted.

r
Access mode, a = anonymous user, r = real (normal) user.

user
Local username authenticated with.

ftp
The service being invoked (almost always FTP).

0
Authentication method, 0 = none, 1 = RFC931 authetication.

*
User ID or * if not available (virtual user).

c
Completion status, c = completed, i = incomplete.

Fonte: http://www.gnode.net/reading-ftp-logs-in-xferlog-format

SSD x HDD

Fonte: http://www.storagereview.com/ssd_vs_hdd

Trocar a senha via um script

chpasswd

Com o comando "chpasswd" da seguinte maneira:

echo "nom:password" | chpasswd

Authentication refused: bad ownership or modes for file .ssh/authorized_keys

When configuring SSH keys to be able to login to a server without a password you mighkeys2t run into a permissions error. If the authorized_keys or authorized_keys2 file has the incorrect permissions it will not authenticate with your ssh-rsa key but instead still require a password. If you are having trouble configuring SSH keys you should check the /var/log/secure file to see if there is an error displaying in that log. You may see the error displayed below.

Error: Authentication refused: bad ownership or modes for file .ssh/authorized_keys

If you see this error it means that the authorized_keys or authorized_keys2 file has the incorrect ownership or permissions. Make sure that the authorized_keys file is owned by the user that will be logged into and the permissions are 600. So if the username is backup you would want the file to look like the below when issuing the “ls -alh” command.

1        -rw------- 1 backup backup 409 Mar 23 19:56 authorized_keys

If the ownership or permissions are different than the above you can accomplish setting the proper ownership and permissions by using the below two commands.

1        chown backup.backup authorized_keys

2        chmod 600 authorized_keys

That should resolve your problems and now from the remote server you should be able to SSH to this server and login without a password.

Fonte: http://www.question-defense.com/2009/03/23/authentication-refused-bad-ownership-or-modes-for-file-sshauthorized_keys

A configuração do Certificado digital no IIS 7 é excluída automaticamente.

Sintoma:

O certificado digital desaparece da configuração do IIS e no event view é exibido a mensagem:

SSL Certificate Settings deleted for Port : 172.17.0.22:443 .

Solução:

Locate the following property in the section of the applicationHost.config file, and delete it:

     5506" dataType="Binary" userType="1" attributes="None" value="oXiHOzFAMOF0YxIuI7soWvDFEzg=" />

This property is a legacy feature from Internet Information Services (IIS) 6.0 and is no longer needed.

Colado de <http://support.microsoft.com/kb/2025598>

O arquivo applicationHost.config pode ser encontrado em:

%windir%\system32\inetsrv\config\applicationHost.config

Colado de <http://learn.iis.net/page.aspx/129/using-configuration-history-with-iis-7-and-iis-8/#Restoring>

 Como testar as operações de SMTP utilizando o Telnet

1. Ligar o Telnet ao Exchange Server que aloja o serviço IMS utilizando a porta 25.
Comando telnet 25
 
2. Ligar o local echo no cliente de telnet para poder ver o que está a escrever.
No Telnet do Win 9x e NT 3.5/4.0 fá-lo através da opção “preferences” do menu “terminal”, e seleccionando o botão de opção do local echo. No Telnet do Windows 2000, escreva o comando "set local_echo", no command prompt.

3. Execute a seguinte sequência de comandos smtp
helo                  
a resposta deve ser a seguinte
250 OK
mail from:
a resposta deve ser a seguinte
250 OK - mail from
rcpt to:
a resposta deve ser a seguinte
250 OK - Recipient
data
a resposta deve ser a seguinte
354 Send data.  Finalizar com CRLF.CRLF
To:
From:
Subject:
.
a resposta deve ser a seguinte
250 OK
quit

Fonte: http://www.rsoutlook.com/exc/telnetsmtp.htm

Performance commands for AIX

How to monitor the utilization for all logical CPUs:

gz@aix~# sar -P ALL 1 4
AIX lpar1 3 5 0XXXXXXXXXXX    12/07/11

System configuration: lcpu=4 ent=0.50 mode=Uncapped 

15:19:45 cpu    %usr    %sys    %wio   %idle   physc   %entc
15:19:46  0       57      37       6       0    0.19    37.3
          1       32      22      12      35    0.07    14.9
          2        0      26       0      74    0.00     0.1
          3        0      32       0      68    0.00     0.1
          U        -       -      11      37    0.24    47.7
          -       26      17      15      42    0.26    52.3
15:19:47  0       53      41       6       0    0.18    35.1
          1       24      23       7      46    0.07    13.9
          2        0      27       0      73    0.00     0.1
          3        0      30       0      70    0.00     0.1
          U        -       -      12      39    0.25    50.9
          -       22      18      15      46    0.25    49.1
15:19:48  0       49      37      13       1    0.29    58.4
          1       17      65      10       9    0.19    38.2
          2        0      26       0      74    0.00     0.1
          3        0      34       0      66    0.00     0.1
          U        -       -       1       3    0.02     3.3
          -       35      46      12       7    0.48    96.7
15:19:49  0       53      42       5       1    0.17    33.9
          1       41      21      21      18    0.08    16.9
          2        0      28       0      72    0.00     0.1
          3        0      30       0      70    0.00     0.1
          U        -       -      14      35    0.25    49.1
          -       25      18      19      39    0.25    50.9

Average   0       52      39       8       0    0.21    41.2
          1       25      41      12      21    0.10    20.9
          2        0      27       0      73    0.00     0.1
          3        0      31       0      69    0.00     0.1
          U        -       -       9      29    0.19    37.8
          -       27      25      15      33    0.31    62.2

How to monitor the system wide processor utilization:

gz@aix~# lparstat 1 3  

System configuration: type=Shared mode=Uncapped smt=On lcpu=4 mem=4096 psize=10 ent=0.50 

%user  %sys  %wait  %idle physc %entc  lbusy  vcsw phint
----- ----- ------ ------ ----- ----- ------ ----- -----
 30.5  39.9    7.7   21.9  0.38  76.4   37.0  1550   286 
 27.3  39.7    6.7   26.2  0.36  72.5   40.5  1641   285 
 35.4  46.1    6.5   12.0  0.43  87.0   37.7  1849   369 

How to display micropartition statistics with topas:

gz@aix~# topas -L
Interval:    2    Logical Partition: lpar1              Wed Dec  7 15:21:00 2011
Psize:       -                Shared SMT  ON           Online Memory:   4096.0
Ent: 0.50                      Mode: UnCapped          Online Logical CPUs:   4
Partition CPU Utilization                              Online Virtual CPUs:   2
%usr %sys %wait %idle physc  %entc %lbusy    app    Vcsw    phint   %hypv   hcalls
  47   33     9    11   0.4  89.44  26.16      -    2492      411    55.9    40144
==================================================================================
LCPU  minpf majpf  intr    csw   icsw runq lpa  scalls usr sys _wt idl   pc   lcsw
Cpu0    292     0  1456   5072   1093    3 100    9643  52  41   6   1 0.24   1166
Cpu1    344     0   706   3622    849    0 100   11180  54  33   8   6 0.21   1285
Cpu2      0     0    10      0      0    0   0       0   0  26   0  74 0.00     20
Cpu3      0     0    11      0      0    0   0       0   0  29   0  71 0.00     20

How to display cpu utilization of all active partitions in the management system:

gz@aix~# topas -C
Topas CEC Monitor             Interval:  10             Wed Dec  7 15:18:23 2011
Partitions Memory (GB)           Processors
Shr:  5    Mon:79.0  InUse:75.0  Shr:8.5  PSz: 10   Don: 0.0 Shr_PhysB  7.29
Ded:  0    Avl:   -              Ded:  0  APP:  1.3 Stl: 0.0 Ded_PhysB  0.00

Host         OS  M Mem InU Lp  Us Sy Wa Id  PhysB  Vcsw Ent  %EntC PhI
-------------------------------------shared-------------------------------------
lpar1        A53 U   28  27 12  89  8  0  2   4.70    0  4.00 117.6   0
lpar2        A53 U   16  14  8  84  9  0  6   1.55 3188  1.50 103.5 1206
lpar3        A53 U   12  12  6  88  5  0  5   0.72 1426  0.50 143.2 610
lpar4        A53 U   16  15  8   3 10  0 85   0.29 3338  1.50  19.1 399
lpar5        A53 U  8.0 7.8  4   0  1  0 97   0.03    0  1.00   3.4   0

Host         OS  M Mem InU Lp  Us Sy Wa Id  PhysB  Vcsw  %istl %bstl
------------------------------------dedicated-----------------------------------

How to collect and display performance statistics for all logical CPUs in the system. In the example below, we will show one time the 20 seconds data:

gz@aix~# mpstat 20 1

System configuration: lcpu=2 ent=0.8 mode=Uncapped 

cpu  min  maj  mpc  int   cs  ics   rq  mig lpa sysc us sy wa id   pc  %ec  lcs
  0  301    0  160  450  556  262    0   22 100 3808 30 60  0 10 0.05  6.8  392
  1   17    0  160  220   59   41    0   23 100  290 14 48  0 38 0.01  0.8  228
  U    -    -    -    -    -    -    -    -   -    -  -  -  0 92 0.74 92.4    -
ALL  318    0  320  670  615  303    0   45 100 4098  2  4  0 93 0.06  7.6  620

List of processes sorted by swap usage:
gz@aix~# ps gv | head -n 1; ps gv | egrep -v "RSS" | sort +5n
to calculate total used:
gz@aix~# ps gv | egrep -v "RSS" | awk '{total+=$5} END{print total}'

List of processes sorted by memory usage:
gz@aix~# ps gv | head -n 1; ps gv | egrep -v "RSS" | sort +6n
to calculate total used:
gz@aix~# ps gv | egrep -v "RSS" | awk '{total+=$6} END{print total}'

How to artificially limit the amount of memory:

gz@aix~# rmss -c 3000 
Simulated memory size changed to 3000 Mb. 

Tool to check the memory and paging space is allocation:
gz@aix~# svmon (with -P you can see per process allocation)

How to determine the amount of asynchronous I/O (legacy) servers configured on your system:
gz@aix~# pstat -a | egrep ' aioserver' | wc -l
or
gz@aix~# ps -ek | grep aioserver | grep -v posix_aioserver | wc -l

How to display virtual memory statistics:

root@aix53# vmstat -w 1 10 

System configuration: lcpu=34 mem=30976MB ent=5.80

 kthr          memory                         page                       faults                 cpu          
------- --------------------- ------------------------------------ ------------------ -----------------------
  r   b        avm        fre    re    pi    po    fr     sr    cy    in     sy    cs us sy id wa    pc    ec
  0   0    7061457     115394     0     0     0     0      0     0  9595   1833 34264 10 11 77  2  1.27  21.9
  1   0    7061454     115397     0     0     0     0      0     0  9201   1709 33079  9 11 77  2  1.23  21.2
 16   0    7061463     115192     0     0     0     0      0     0 12316   9676 33034 11 19 69  1  1.80  31.0
  3   0    7061464     114619     0     0     0     0      0     0 10842   6207 33429 10 17 68  5  1.66  28.6
  2   0    7061638     114443     0     0     0     0      0     0  6906   4124 28329  7 13 69 12  1.23  21.2
  0   0    7061131     114942     0     2     0     0      0     0  5757   2354 23583  5  9 75 11  0.90  15.5
  5   0    7061613     114457     0     2     0     0      0     0  6230   7724 23951  6  9 77  8  0.96  16.6
  1   0    7062157     113913     0     0     0     0      0     0  6340   2021 24501  6  8 81  5  0.90  15.4
  0   0    7062334     113736     0     0     0     0      0     0  5897   2530 22285  5  7 84  4  0.80  13.7
  2   0    7062425     113645     0     0     0     0      0     0  7378   2931 28937  6  9 82  3  0.92  15.8

A script to get memory utilization:

gz@aix~# cat meminfo
#!/usr/bin/ksh
#
# Quick view of memory usage under AIX
#
 
USED=`svmon -G | head -2 | tail -1 | awk '{ print $3 }'`
USED=`expr $USED / 256`
TOTAL=`lsattr -El sys0 -a realmem | awk '{ print $2 }'`
TOTAL=`expr $TOTAL / 1000`
FREE=`expr $TOTAL - $USED`
 
echo "\nMemory Information"
echo "=================="
echo "total memory = $TOTAL MB"
echo "free memory  = $FREE MB"
echo "used memory  = $USED MB"
 
exit 0 

Fonte: http://docs.gz.ro/aix-performance-commands

Backup commands for AIX

Creates image.data and system backup (-X expands /tmp if required):
#mksysb -i -X /dev/rmt0

Creates image.data file with map file and system backup:
#mksysb -m /dev/rmt0

Creates system data but excludes the files listed in /etc/exclude.rootvg:
#mksysb -e /dev/rmt0

Creates /image.data file:
#mkszfile

Creates system boot backup to the CD-R device /dev/cd1:
#mkcd -d /dev/cd1

Creates backup of vg vg00 to CD-R device /dev/cd1:
#mkcd -d /dev/cd1 -v vg00

Creates generic boot backup:
#mkcd -d /dev/cd1 -G

Creates vg00.data image file and backup vg vg00:
#savevg -i -f /dev/rmt0 vg00

Creates vg00 backup but excludes files listed in the /etc/exclude.vg00:
#savevg -ef /dev/rmt0 vg00

Backup entire system to rmt0:
#find / -print | backup -ivf /dev/rmt0

Backup /home directory to rmt0 with backup level 0:
#backup -0vf /dev/rmt0 /home

List the archive in rmt0:
#restore -Tvf /dev/rmt0

Restore /home from archive in device rmt0:
#restore -xvf /dev/rmt0 /home

Restores particular file from /export/mksysb image:
#restore –xvf /export/mksysb ./etc/sshd.conf

Archives /home directory:
#find ./home -print |cpio -ocvumB > /dev/rmt0

Create an archive of /home directory:
#tar cvf /tmp/home.tar /home

Restores cpio archive from rmt0:
#cpio -icvdumB < /dev/rmt0

List the contents of cpio archive from rmt0:
#cpio -ivt < /dev/rmt0

Restores /home directory from rmt0:
#cpio -icvd < /dev/rmt0 /home

Archives /home to rmt0 device:
#tar -cvf /dev/rmt0 /home

List the archives in rmt0:
#tar -tvf /dev/rmt0

Extract /home from rmt0:
#tar -xvf /dev/rmt0 /home

Convert and copy ascii file si to ebcdic si1:
#dd if=si of=si1 conv=ebcdic

To copy blocks from rmt0 with 512 blocks to rmt1 with 1024 blocks:
#dd if=/dev/rmt0 ibs=512 obs=1024 of=/dev/rmt1

To rewind the tape:
#tctl -f /dev/rmt0 rewind

To eject the tape:
#tctl -f /dev/rmt0 offline

To show the status of tape:
#tctl -f /dev/rmt0 status

To change the block size of the tape to 512:
#chdev -l rmt0 -a block_size=512

How to restore a file from mksysb:
# listvgbackup -f /path/to/mksysb.image -r ./etc/file

Fonte: http://docs.gz.ro/node/20



SRC – Gerenciamento de daemons no AIX

O AIX tem um gerenciador de daemons, chamado SRC, em inglês, “System Resource Controller“.
Através do SRC podemos verificar se um serviço está ativo, parar, iniciar ou reinicializar um serviço.

Isto pode ser feito através dos seguintes comandos:

startsrc: iniciar
refresh: reiniciar
stopsrc: parar
lssrc: verificar status

O SRC permite trabalharmos com um serviço ou um grupo de serviços. Para um serviço, usamos a opção “-s” e para um grupo, “-g”.
Por exemplo, para gerenciar os serviços de NFS:
Verificando status do grupo de serviços:

# lssrc -g nfs
Subsystem            Group    PID    Status
biod                nfs                                     inoperative
nfsd                nfs                inoperative
rpc.statd         nfs                inoperative
rpc.lockd         nfs                inoperative
rpc.mountd          nfs                inoperative

Iniciando um serviço:

# startsrc -s nfsd
# lssrc -g nfs
Subsystem         Group            PID     Status
nfsd             nfs              23672   active
biod             nfs                      inoperative
rpc.statd        nfs                      inoperative
rpc.lockd        nfs                      inoperative
rpc.mountd       nfs                      inoperative

Iniciando um grupo de serviços:

# startsrc -g nfs
0513-059 The biod Subsystem has been started. Subsystem PID is 17242.
0513-029 The nfsd Subsystem is already active.
Multiple instances are not supported.
0513-059 The rpc.statd Subsystem has been started. Subsystem PID is 19862.
0513-059 The rpc.lockd Subsystem has been started. Subsystem PID is 24236.
0513-059 The rpc.mountd Subsystem has been started. Subsystem PID is 6802.

# lssrc -g nfs
Subsystem         Group            PID     Status
nfsd             nfs              23672   active
biod             nfs              17242   active
rpc.statd        nfs              19862   active
rpc.lockd        nfs              24236   active
rpc.mountd       nfs              6802    active

Parando um grupo de serviços:

# stopsrc -g nfs
0513-044 The nfsd Subsystem was requested to stop.
0513-044 The biod Subsystem was requested to stop.
0513-044 The rpc.statd Subsystem was requested to stop.
0513-044 The rpc.lockd Subsystem was requested to stop.
0513-044 The rpc.mountd Subsystem was requested to stop.

# lssrc -g nfs
Subsystem         Group            PID     Status
biod             nfs                      inoperative
nfsd             nfs                      inoperative
rpc.statd        nfs                      inoperative
rpc.lockd        nfs                      inoperative
rpc.mountd       nfs                      inoperative

Fonte: http://www.unixnotes.org/2007/01/31/src-gerenciamento-de-daemons-no-aix 

AIX - Identificando portas abertas

É muito importante conhecer o ambiente que está sendo administrado. Em se tratando de servidores, muitas vezes temos em um ambiente muitas portas abertas (em modo listen), e é importante saber qual processo está ouvindo em uma determinada porta, por questões de segurança e até em situações de troubleshooting.

A dica de hoje é identificar, no AIX, qual processo está sendo executado em uma porta específica.

Método 1 - Usando os comandos netstat e rmsock

Protocolo TCP:

# netstat -Aan |grep *.1334
f1000e0002b753b0 tcp4       0      0  *.1334             *.*                LISTEN

# rmsock f1000e0002b753b0 tcpcb
The socket 0x2b75008 is being held by proccess 5701822 (writesrv).

# ps -ef |grep 5701822
root  5701822  1507536   0   Jun 10      -  0:00 /usr/sbin/writesrv

Como podem ver o processo writesrv está sendo executado na porta 1334.

Protocolo UDP:
# netstat -Aan |grep *.514
f1000e0002a67e00 udp4       0      0  *.514              *.*

# rmsock f1000e0002a67e00 inpcb
The socket 0x2a64c08 is being held by proccess 5308580 (syslogd).

# ps -ef |grep 5308580
root  5308580  1507536   0   Jun 10      -  0:36 /usr/sbin/syslogd

A porta 514 UDP está sendo utilizada pelo processo do syslogd.

Método 2 - Utilizando os comandos netstat e kdb (kernel debuger)

# netstat -Aan |grep 1334
f1000e0002b753b0 tcp4       0      0  *.1334             *.*                LISTEN

# kdb
(0)>
(0)> sockinfo f1000e0002b753b0 tcpcb

[... A saída do comando kdb é bem detalhado, e por isso foi truncado. O importante para nós é a ultima linha, como mostrado abaixo ... ]

proc/fd: 87/3
proc/fd: fd: 3
              SLOT NAME     STATE      PID    PPID          ADSPACE  CL #THS

pvproc+015C00   87*writesrv ACTIVE 05700BE 01700D0 0000001190239480   0 0001

O importante é saber o PID do processo, que está em hexadecimal na coluna PID.
 
Para converter de hexadecimal para decimal, basta utilizar o comando hcal, dentro do prompt do kdb. Como mostrado abaixo.

(0)>
(0)>
(0)> hcal 05700BE
Value hexa: 005700BE          Value decimal: 5701822
(0)> quit

De volta ao shell, verificar qual programa pertence ao PID 5701822.

# ps -ef |grep 5701822
root  5701822  1507536   0   Jun 10      -  0:00 /usr/sbin/writesrv

O mesmo procedimento pode ser utilizado para portas UDP, sempre trocando o parâmetro tcpcb por inpcb.

Dica válida para AIX versões 5.3 e 6.1

Fonte: http://www.vivaolinux.com.br/dica/AIX-Identificando-portas-abertas

Internet Explorer deixa de ser preferência da maioria dos usuários

Após décadas de domínio, o IE passa a deter menos de 50% dos acessos à world wide web no mundo.

Leia mais em: http://www.tecmundo.com.br/internet/14949-internet-explorer-deixa-de-ser-preferencia-da-maioria-dos-usuarios.htm#ixzz1d0qoOwpb

Fita HP LTO Ultrium 5 3TB - PN: C7975A

Especificações técnicas
Tecnologia de gravação	LTO-5 Ultrium
Etiquetas de suportes	Write-on Labels in box
Quantidade por embalagem	1
Capacidade de armazenamento	3.0 TB; Compressed 2:1; Supported
Cor de produto	Light Blue
Comprimento de tape	846 m
Largura da fita	12.65 mm
Espessura de tape	6.4 um
Força magnética coerciva	2500-2700 Oe
Formato do suporte	Re-Writable

Itens incluídos
Declaração de garantia standard	Limited Lifetime

Compatibilidade
Compatibilidade de unidade	Storage Media Compatibility Matrix
url de compatibilidade de unidade	http://www.hptapecompat.com

Kilobytes, Megabytes, Gigabytes, Terabytes... e agora, os Zettabytes!

Um zettabyte corresponde ao número 1 seguido de 21 zeros. Computação em nuvem deverá ser a responsável por armazenar tanta informação.

1 Bit = Um dígito binário
8 Bits = 1 Byte
1024 Bytes = 1 Kilobyte
1024 Kilobytes = 1 Megabyte
1024 Megabytes = 1 Gigabyte
1024 Gigabytes = 1 Terabyte
1024 Terabytes = 1 Petabyte
1024 Petabytes = 1 Exabyte
1024 Exabytes = 1 Zettabyte
1024 Zettabytes = 1 Yottabyte
1024 Yottabytes = 1 Brontobyte
1024 Brontobytes = 1 Geopbyte

How to convert MBps to IOPS or calculate IOPS from MB/s

Most SSDs have two speed ratings for reading as well as for writing.  The first rating is the sustained MB/s performance, which is the main marketing most manufacturers use.  The second rating is the 4K Random IOPS performance, which gives a much better idea of how the drive will perform in the real world.  The sustained MB/s rating is the sequential transfer rate the SSD will maintain continuously, such as over a period of 30 seconds.  The 4K Random IOPS on the other hand is how many 4K (4096 byte) operations the drive will handle per second with each block being read or written to a random position. 
Usually when a Random 4K IOPS figure is given, it may state that this is at a certain queue depth, such as 4, 16, 32 or 64.  With a queue depth of 4, this means that there are 4 separate threads taking place with the drive, each thread independently running its own transfers.  With the use of Native Command Queuing (NCQ), the SSD can handle these threads simultaneously to improve the overall throughput compared to running a single thread.  While many hard disks use native command queuing to line up read/write operations to minimise seek times between each read/write operation, SSDs can read from and write to multiple NAND cells simultaneously, where as the read/write head in a hard disk can only be in one physical place at any time.
While it is nice to see how many IOPS a drive is capable of, it is also useful to see how this translates into actual throughput or even vice versa.  For example, most benchmark tools such as CrystalDiskMark and AS SSD report the random 4K performance in throughput, i.e. MB/s, while the SSD’s specifications usually rates the 4K performance in IOPS.
To see how to translate MBps into IOPS and vice versa, we need to do a little math:

IOPS = (MBps Throughput / KB per IO) * 1024
Or
MBps = (IOPS * KB per IO) / 1024

So let’s say we have an SSD claiming a Random 4K write speed of 20,000 IOPS and it achieves 76.2MB/s in the CrystalDiskMark with the QD32 write test.
To convert the 76.2MB/s to IOPS, we perform the following calculation:

IOPS = (76.2 / 4) * 1024
IOPS = 19.1 * 1024
IOPS = 19,558.4

To see what throughput we need to achieve to match the actual 20,000 IOPS claim, we can perform this calculation in reverse:

MBps = (20,000 * 4) / 1024
MBps = 80,000 / 1024
MBps = 78.125MB/s

Note that each manufacturer uses its own method of coming up with their SSD IOPS ratings.  Besides separate IOPS ratings for read and write speeds, a given SSD can behave quite different depending on the type of data being read or written, as well as the duration this transfer takes place.  For example, an SSD that achieves 5,000 Random 4K IOPS sustained write over a period of 30 seconds may only achieve 1,000 IOPS sustained write over a period of 5 minutes.  For SSDs using the SandForce processor, the compressibility of the data also has an impact, so two benchmark tools may show completely different IOPS readings if one tool sends uncompressible data and the other tool sends highly compressible data and also if one runs the benchmark for longer duration than the other.

Maintain wtmp on AIX

In /var/adm/wtmp on AIX maintains a list of past user sessions and information about the restart/shutdown of that particular system. While this file is normally very small in terms of file size, on an active box, this can grow if not properly maintained. You can use the “last” command to read wtmp, or export it to a text file for further processing with “fwtmp”. While you can simply redirect nothing into wtmp to empty it out “>/var/adm/wtmp”, it’s always a good idea to keep this file (or at least a backup) for security/auditing reasons.

Below is a simple script which will rotate the last 1000 entries in wtmp and discard the rest.

#!/bin/ksh 
#
# Maintain the last 1000 lines in /var/adm/wtmp
# and discard the rest.
#
if [ -s /var/adm/wtmp ]; then 
   /usr/sbin/acct/fwtmp < /var/adm/wtmp > /tmp/wtmp.tmp 
   /usr/bin/tail -1000 /tmp/wtmp.tmp | /usr/sbin/acct/fwtmp -ic > /var/adm/wtmp 
   /usr/bin/rm /tmp/wtmp.tmp
else 
   continue 
fi

Linux on Power Systems Servers overview
 

IBM® Power Systems™ Servers allow you to run Linux® applications, while taking advantage of POWER® hardware performance, availability, and reliability features.

You can use the IBM Installation Toolkit to install Linux on your Power Systems server. Then, virtualize your system and configure open source workloads using the IBM Installation Toolkit for Linux Simplified Setup Tool (Simplified Setup Tool).

• Installing Linux with the IBM Installation Toolkit
  The IBM Installation Toolkit for Linux provides a set of tools and functions that simplifies the installation of Linux on Power Systems Servers.
• Linux on Power Systems Servers and open source workloads
  This topic collection guides you through configuring the file and print server, web server, network infrastructure server, and mail server open source workloads on the Linux on Power system using the IBM Installation Toolkit Simplified Setup Tool (Simplified Setup Tool). This topic collection also instructs you on setting up a virtualized environment in which to run the open source workloads.

Continue with the following topics for information about supported features, supported distributions, and additional resources for installing Linux on Power Systems Servers.

• Supported features for Linux on Power Systems servers
  Use this chart to find the Linux distribution version that supports each system feature. Feature support is shown for Red Hat Enterprise Linux and Novell SUSE Linux Enterprise Server (SLES).
• Supported Linux distributions for POWER7 and POWER6 Servers
  Use these charts to find the supported Linux distributions for Power Systems servers.
• Resources for installing Linux on Power Systems Servers
  Use these information resources to install Linux on Linux on Power Systems Servers.

Building Apache2 From Source on Linux (Redhat 8)

 

This page shows the steps used to compile and build apache2 on linux. The example uses Apache 2.0.46 on Redhat 8 using a bash shell, you will need gcc installed. You can find Apache's install instructions here
Downlaod the latest tar.gz file for apache2

You can download it from httpd.apache.org.
Login as root

You can type su to switch to root. Then run source /etc/profile to ensure that your path environment variable is setup properly.
Extract the source code

In this example we extract the source code to a directory under /usr/local/src/

cp httpd-2.0.46.tar.gz /usr/local/src

 cd /usr/local/src

 gunzip httpd-2.0.46.tar.gz

 tar -xvf httpd-2.0.46.tar

 rm -f httpd-2.0.46.tar

 cd httpd-2.0.46

Now you should be in the directory that contains the source code. Set compiler options (optional)

If you want you can set some compiler options, this is typically done to create optimized code. One very common thing to do is to set CFLAGS=-O2 or CFLAGS=-O3 (that's an Oh, not a Zero) that tells the compiler how much code optimization to do, setting it to a higher value does more optimization, but also takes longer to compile and may potentially cause unexpected things (not common). O2 is a fairly safe level to use. To do this type the following:

export CFLAGS=-O2

You can also tell the compiler what kind of CPU you have to perform more optimizations, I'm not going to get into that here, but if your interested check out the GCC manual. Run autoconf (configure)

Now you need to set the configuration options, and check that all libraries needed to compile are present. This is done with a script called configure, to find out what options you can set type the following:

./configure --help

You will see quite a few options there, we will set the prefix (the directory to install apache, we picked /usr/local/apache2) and also tell it which modules to compile and install. We will tell configure to compile and install all modules as shared DSO libraries, that way we can easily enable and disable them in the httpd.conf file. Here's how we ran configure:

configure --prefix=/usr/local/apache2 --enable-mods-shared=all

Compile Apache

Now to compile apache we run make this compiles the source code into executable binaries.

make

Installing Apache

The next step copies the binaries into the install directory, and sets up the modules.

make install

Starting/Stopping/Restarting Apache

Now to start/stop apache use apachectl in the bin directory of your install dir.

cd /usr/local/apache2/bin
 
 ./apachectl start
 
 ./apachectl stop
 
 ./apachectl restart

A script for init.d (optional)

Here's a script you can save to /etc/init.d/httpd it is a modified version of the one that came in the rpm for Apache 2.0.40

#!/bin/bash
#
# Startup script for the Apache Web Server
#
# chkconfig: - 85 15
# description: Apache is a World Wide Web server.  It is used to serve \
#              HTML files and CGI.
# processname: httpd
# pidfile: /usr/local/apache2/logs/httpd.pid
# config: /usr/local/apache2/conf/httpd.conf

# Source function library.
. /etc/rc.d/init.d/functions

if [ -f /etc/sysconfig/httpd ]; then
        . /etc/sysconfig/httpd
fi

# This will prevent initlog from swallowing up a pass-phrase prompt if
# mod_ssl needs a pass-phrase from the user.
INITLOG_ARGS=""

# Path to the apachectl script, server binary, and short-form for messages.
apachectl=/usr/local/apache2/bin/apachectl
httpd=/usr/local/apache2/bin/httpd
pid=$httpd/logs/httpd.pid
prog=httpd
RETVAL=0


# The semantics of these two functions differ from the way apachectl does
# things -- attempting to start while running is a failure, and shutdown
# when not running is also a failure.  So we just do it the way init scripts
# are expected to behave here.
start() {
        echo -n $"Starting $prog: "
        daemon $httpd $OPTIONS
        RETVAL=$?
        echo
        [ $RETVAL = 0 ] && touch /var/lock/subsys/httpd
        return $RETVAL
}
stop() {
        echo -n $"Stopping $prog: "
        killproc $httpd
        RETVAL=$?
        echo
        [ $RETVAL = 0 ] && rm -f /var/lock/subsys/httpd $pid
}
reload() {
        echo -n $"Reloading $prog: "
        killproc $httpd -HUP
        RETVAL=$?
        echo
}

# See how we were called.
case "$1" in
  start)
        start
        ;;
  stop)
        stop
        ;;
  status)
        status $httpd
        RETVAL=$?
        ;;
  restart)
        stop
        start
        ;;
  condrestart)
        if [ -f $pid ] ; then
                stop
                start
        fi
        ;;
  reload)
        reload
        ;;
  graceful|help|configtest|fullstatus)
        $apachectl $@
        RETVAL=$?
        ;;
  *)
        echo $"Usage: $prog {start|stop|restart|condrestart|reload|status"
  echo $"|fullstatus|graceful|help|configtest}"
        exit 1
esac

exit $RETVAL

Next run chkconfig to setup runlevels for which httpd will run:

 chkconfig --add httpd
 
 chkconfig --level 2345 httpd on
 
 chkconfig --list
 

Uninstall old rpm packages (Optional)

If you have old rpm apache packages installed, you can check by running:

rpm -q httpd
 

In my case it lists the following:

redhat-config-httpd-1.0.1-13
httpd-2.0.40-11.3
httpd-manual-2.0.40-11.3

To uninstall one of the rpm's type rpm -e packagename

rpm -e httpd-2.0.40-11.3
 

It may tell you that you have other packages that depend on httpd, you will have to uninstall them first before you can remove the old httpd server.

How Do I Install AIX 64-bit?

The simple answer is you don’t. You install AIX normally, which by default installs a 32-bit kernel (at least 32-bit is default for AIX 5.3). Then you change your kernel and reboot.
I have AIX running on top of (as a client partition of) Virtual I/O (VIO) Server, which is IBM’s virtualization version of VMware.  Does VIO server allow 64-bit client OS installs?  Yes.

Does My System Support AIX 64-bit?

Check whether your kernel is currently 32-bit:
AIX# bootinfo -K
32
Your AIX version must be 5.1 or above:
AIX# oslevel
5.3.0
Verify that your hardware supports 64 bits:
AIX# bootinfo -y
64

How to Change Your 32-bit AIX Kernel to 64-bit

1) Create/overwrite your links to the Unix kernel:
ln -sf /usr/lib/boot/unix_64 /unix
ln -sf /usr/lib/boot/unix_64 /usr/lib/boot/unix
2) Verify:
ls -l /unix
ls -l /usr/lib/boot/unix
lsvg -l rootvg
3) Create your boot image and restart:
lslv -m hd5
bosboot -ad /dev/ipldevice
shutdown -Fr
Note: If you have LSOF installed, make sure you’re running the 64-bit version.  Check out the last part of my How to Install LSOF post.
4) After you reboot, verify your OS Kernel:
bootinfo -K

How to Revert Back from 64-bit to 32-bit:

From 64-bit to 32-bit:
ln -sf /usr/lib/boot/unix_mp /unix
ln -sf /usr/lib/boot/unix_mp /usr/lib/boot/unix
lslv -m hd5
bosboot -ad /dev/ipldevice
shutdown -Fr
Tags: 32-bit, 64-bit, AIX 5.3, bootinfo, bosboot, osleve, VIO, VIOS, Virtual I/O Server

This entry was posted on Wednesday, August 6th, 2008 at 2:59 pm and is filed under AIX, Unix. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

Tudo o que acontece na internet em apenas 60 segundos

Infográfico mostra o que pode acontecer na internet em apenas 1 minuto.
Mais de 20 tarefas entram na lista.

Dez mandamentos para resolução de problemas em TI

Não importa quão profundo sejam os conhecimentos técnicos de uma equipe de TI. Sem metodologia adequada, a solução de problemas torna-se um processo muito mais complicado.

O CIO da Escola de Medicina da Harvard e de um dos maiores grupos de assistência médica dos EUA, John Halamka, baseou-se em sua experiência para elaborar uma lista com os 10 principais segredos para resolver os problemas com rapidez e experiência.

1 – Uma vez que algum problema foi identificado, verifique seu real alcance – O software de monitoramento pode até dizer que tudo está bem, mas é bom não se contentar. O ideal é conversar com os usuários, testar a aplicação ou infraestrutura sozinho e ter certeza sobre o que originou uma reclamação.

2 – Quando o alcance do problema alarmado é muito grande e a raiz ainda é desconhecida, acione um plano de emergência – É muito melhor mobilizar toda a equipe para um falso alarme ocasional do que intervir tarde demais e quando o problema alcançar proporções muito grandes com uma resposta lenta do departamento de TI.

3 – O processo de solução de um problema deve ser visível, atualizado constantemente para todos e participativo – Muitas vezes os profissionais técnicos ficam tão focados na sua tarefa que perdem a noção do tempo, não se atualizam mutuamente e deixam de conversar com outras áreas. A companhia deve ter uma abordagem multidisciplinar com relatórios de progressos pré-determinados para prevenir a isolação e a busca por soluções que têm poucas chances de darem certo.

4 – Mesmo com a rotina de atualizações e relatórios, a equipe deve ficar livre para trabalhar – Alguns líderes de TI gostam de retornos constantes de sua equipe e isso não é necessariamente ruim. Mas se a equipe gastar 90% do seu tempo reportando o status do trabalho, fica muito mais difícil solucionar problemas em prazo razoável.

5 – A explicação mais simples geralmente é a correta – Halamka relata que, em um incidente recente em sua corporação, todas as evidências apontaram para o mal-funcionamento em um componente do firewall. Mas todos as ferramentas de testes e diagnósticos indicavam que o firewall funcionava perfeitamente. Alguns levantaram a hipótese de que a empresa sofria um tipo muito específico de ataque de negação de serviços. Outros aventaram a possibilidade de uma falha em componentes das redes Windows dos servidores. Surgiu ainda a possibilidade de um ataque incomum por vírus. A explicação mais simples, do firewall, foi comprovada correta após a remoção do mesmo da infraestrutura da rede. E, segundo Halamka, a regra da explicação mais simples ser a resposta até mesmo para problemas mais complexos é verdadeira na maioria das vezes.

6 – Os prazos devem ser definidos de maneira responsável – O que mais irrita os usuários não é exatamente a demora, mas a definição de prazos imprecisos e os consequentes pedidos de “só mais uma hora para resolver o problema”. Se uma indisponibilidade de sistema ocorrer por conta de uma mudança planejada de infraestrutura, a questão é ainda mais séria: o melhor a se fazer é definir um prazo preciso e respeitá-lo.

7 – Comunique-se com os usuários o máximo possível – A maioria dos stakeholders da empresa estão dispostos a tolerar indisponibilidade se você explicar exatamente as ações que estão sendo tomadas para restaurar o serviço. Os principais executivos de TI são os maiores alvos dessa dica, pois devem mostrar compromisso, presença e liderança.

8 – Orgulho não deve atrapalhar a solução – É difícil assumir erros e desafiador reconhecer o que não se sabe. Mas em vez de gastar tempo procurando culpados por problemas, o foco deve ser em examinar a raiz da indisponibilidade e depois definir processos para prevenir a repetição dos problemas.

9 – Não cante vitória antes do tempo – É tentador presumir que os problemas foram resolvidos e dizer a todos os usuários sobre a suposta vitória. Mas o melhor é esperar 24 horas seguidas de serviços ininterruptos antes de declarar o problema resolvido.

10 – Líderes de TI devem focar na sua trajetória, não em sua posição cotidiana – Indisponibilidades podem causar diversas emoções, como ansiedade, medo de perder o emprego ou a reputação e tristeza pelo impacto causado nos usuários. Nessas horas, a melhor coisa é ter em mente que o tempo é capaz de curar qualquer coisa e que incidentes eventuais serão esquecidos. Com o passar da trajetória profissional, a comunidade de usuários tende a observar mais a consistência e o processo contínuo de melhoria de qualidade do que episódios isolados.

De uma forma geral, problemas são dolorosos, mas capazes de unir pessoas. Nos piores momentos é que se constrói relações de confiança, criação de novos canais de comunicação e melhoria de processos.

(http://cio.uol.com.br/gestao/2011/06/06/dez-mandamentos-para-resolucao-de-problemas-em-ti)

Computerworld/EUA

Publicada em 06 de junho de 2011 às 07h15

Copyright 2011 Now!Digital Business Ltda. Todos os direitos reservados.