Disable Windows 7 hotkeys

March 17th, 2014 No comments

This little script disables Windows 7 hotkeys if you have no local admin rights and registry editor (regedit) is also disabled.  Simply save it as hkey.vbs and execute.

Option Explicit
'Declare variables
Dim WSHShell, rr, MyBox, val, ttl
Dim jobfunc, itemtype
On Error Resume Next
Set WSHShell = WScript.CreateObject("WScript.Shell")
val = "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\DisabledHotkeys"
itemtype = "REG_EXPAND_SZ"
ttl = "Result"
jobfunc = "Value: "
'write the registry key value.
WSHShell.RegWrite val, "1234567890", itemtype
rr = WSHShell.RegRead(val)
MyBox = MsgBox(jobfunc & rr, 4096, ttl)

This example disabled WIN+0 – WIN+9 keys. To disable other keys simply modify second RegWrite parameter.
For more technical info on windows hotkey codes see http://www.geoffchappell.com/notes/windows/shell/explorer/globalhotkeys.htm

Categories: how-to Tags:

75 EUR AdWords Coupon

March 5th, 2013 No comments

Another AdWords coupon for 75 EUR (25 EUR investment required).

67LGK-DLG3Q-W466

First takes !

Categories: Uncategorized Tags:

OpenVPN OCC ping patch

May 28th, 2012 No comments

Hello,

i’ve created simple patch for OpenVPN implementing OCC ping. Main difference of OCC ping and existing OpenVPN ping is that OCC ping is being actively replied on other side of the communication channel. This way you can configure various per-client channel reliability policies:

  • Non-mobile clients might ping more frequently to ensure stable connection, and reconnect as soon as possible in case of failure.
  • Mobile clients (ie. Android phones) might ping less frequently to save battery.

OCC ping can be enabled with (boolean) occ-ping directive and it integrates with all existing ping settings (ping/ping-restart/… directives) – simply instead of ‘normal’ pings OCC pings will be send.

Additionally occ-ping-compat directive makes it possible to use backward compatible OCC pings, that sends instead of newly implemented OCC_PING message, already existing OCC_REQUEST that will be always replied  by other side with OCC_REPLY. This makes it possible to use this new behavior with clients running openvpn without having OCC ping implemented.

Patch can be found here: openvpn-2.2.2-occ-ping.patch.

Categories: devel Tags:

Fixing pg_dump invalid memory alloc request size

May 19th, 2012 No comments

I’ve encountered unusual problem while dumping one postgresql database. Every try to run pg_dump resulted in this:

sam@cerberus:~/backup$ pg_dump -v -c js1 >x
pg_dump: Error message from server: ERROR: invalid memory alloc request size 18446744073709551613
pg_dump: The command was: COPY job.description (create_time, job_id, content, hash, last_check_time) TO stdout;
pg_dump: *** aborted because of error

or this

sam@cerberus:~/backup$ pg_dump -v -c --inserts js1 >x
pg_dump: Error message from server: ERROR: invalid memory alloc request size 18446744073709551613
pg_dump: The command was: FETCH 100 FROM _pg_dump_cursor
pg_dump: *** aborted because of error

Few weeks ago I’ve encountered almost fatal failure of two(!) disks in my RAID5 array – well really funny situation, and a bit uncomfortable way how to find out why not having monitoring and alarming system is a really bad idea ;)
Fortunately no serious data damage happened, postgresql seemed to recover from this, without any problems and my databases worked fine – until I’ve tried to perform a database dump.

And now comes the important question, how to find out which table rows are incorrect (and pg_filedump says everything is OK) ?
And the answer is, use custom function:

CREATE OR REPLACE FUNCTION
find_bad_row(tableName TEXT)
RETURNS tid
as $find_bad_row$
DECLARE
result tid;
curs REFCURSOR;
row1 RECORD;
row2 RECORD;
tabName TEXT;
count BIGINT := 0;
BEGIN
SELECT reverse(split_part(reverse($1), '.', 1)) INTO tabName;
OPEN curs FOR EXECUTE 'SELECT ctid FROM ' || tableName;
count := 1;
FETCH curs INTO row1;
WHILE row1.ctid IS NOT NULL LOOP
result = row1.ctid;
count := count + 1;
FETCH curs INTO row1;
EXECUTE 'SELECT (each(hstore(' || tabName || '))).* FROM '
|| tableName || ' WHERE ctid = $1' INTO row2
USING row1.ctid;
IF count % 100000 = 0 THEN
RAISE NOTICE 'rows processed: %', count;
END IF;
END LOOP;
CLOSE curs;
RETURN row1.ctid;
EXCEPTION
WHEN OTHERS THEN
RAISE NOTICE 'LAST CTID: %', result;
RAISE NOTICE '%: %', SQLSTATE, SQLERRM;
RETURN result;
END
$find_bad_row$
LANGUAGE plpgsql;

It goes over all records in given table, expands them one by one – what will results in exception if some expansion occurs. Exception will also contain CTID of last correctly processed row. And next row with higher CTID will be the corrupted one.
Like this:

js1=# select find_bad_row('public.description');
NOTICE: LAST CTID: (78497,6)
NOTICE: XX000: invalid memory alloc request size 18446744073709551613
find_bad_row
--------------
(78497,6)
(1 row)
js1=# select * from job.description where ctid = '(78498,1)';
ERROR: invalid memory alloc request size 18446744073709551613
js1=# delete from job.description where ctid = '(78498,1)';
DELETE 1
js1=# select find_bad_row('job.description');
NOTICE: rows processed: 100000
NOTICE: rows processed: 200000
NOTICE: rows processed: 300000
NOTICE: rows processed: 400000
NOTICE: rows processed: 500000
NOTICE: rows processed: 600000
NOTICE: rows processed: 700000
NOTICE: rows processed: 800000
find_bad_row
--------------
(1 row)

 

Note: this function requires hstore postgresql extension – it is part of postgresql distribution, you may need to create it with:

CREATE EXTENSION hstore;

 

Records in this table are not that important, and I can restore them from external source – so I could delete this corrupted row. If you can’t you will have to play directly with data files – like described here – good luck :)

Categories: admin, rdbms, time saver Tags:

Monitoring disk drives via collectd

April 17th, 2012 No comments

I’ve made two simple (but useful) disk drive monitoring scripts for collectd exec plugin. You can find them on http://devel.dob.sk/collectd-scripts/.

smartmon.sh

This script monitors SMART attributes of given disks using smartctl (smartmontools).

megamon.sh

This one monitors some interesting values of MegaRaid adapter physical drives using MegaCli tool.

 

Description how to use them can be found within scripts itself – enjoy ;)

Categories: admin, devel, time saver Tags: