Date: Sat, 1 Dec 2007 13:16:01 +0100
From: Tomasz Ostrowski <tometzky@batory.org.pl>
To: Martin Marques <martin@marquesminen.com.ar>
Cc: rihad@mail.ru, pgsql-general@postgresql.org
Subject: Re: full_page_writes = off?
Message-ID: <20071201121601.GB2552@batory.org.pl>
References: <4751150F.8080604@mail.ru> <20071201114754.GA2552@batory.org.pl>
	<47514DDC.70607@marquesminen.com.ar>
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On Sat, 01 Dec 2007, Martin Marques wrote:

>> Also check whether a disks have write-caching turned off - it should.
>> On Linux the command is:
>> 	# hdparm -W /dev/sda
>> 	/dev/sda:
>> 	 write-caching =  0 (off)
>
> Uh? That command as was written lacks an argument for -W (0/1). From the 
> hdparm --help:
>
>  -W   set drive write-caching flag (0/1) (DANGEROUS)
>
> # hdparm -V
> hdparm v6.9

# hdparm -V
hdparm v7.7
# hdparm --help 2>&1 | grep write-caching
 -W   get/set drive write-caching flag (0/1)

You can also use "hdparm -I" to check this - look for a "Write
caching" in "Commands/features" section. If it has a "*" in front
then it is enabled and dangerous.

Regards
Tometzky
-- 
...although Eating Honey was a very good thing to do, there was a
moment just before you began to eat it which was better than when you
were...
                                                      Winnie the Pooh