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Thread: doc hdparm also support SATA

doc hdparm also support SATA

From
Jov
Date:
from the pg doc：
http://www.postgresql.org/docs/devel/static/wal-reliability.html :On Linux, IDE drives can be queried using hdparm -I; write caching is enabled if there is a * next to Write cache. hdparm -W 0 can be used to turn off write caching. SCSI drives can be queried using sdparm. Use sdparm --get=WCE to check whether the write cache is enabled and sdparm --clear=WCE to disable it.

from the hdparm man page :
http://linux.die.net/man/8/hdparm :hdparm - get/set SATA/IDE device parameters

so,the doc is out date, it should mention hdparm also support SATA.

and this doc section current contains more IDE than SATA driver , but nowadays, IDE driver is nearly dead, it hardly buy one IDE hard disk on the market. so we should write more doc about SATA than IDE.   

best regards,
--
Jov

Re: doc hdparm also support SATA

From
Craig Ringer
Date:
On 04/07/2013 02:29 PM, Jov wrote:
from the pg doc：
http://www.postgresql.org/docs/devel/static/wal-reliability.html :On Linux, IDE drives can be queried using hdparm -I; write caching is enabled if there is a * next to Write cache. hdparm -W 0 can be used to turn off write caching. SCSI drives can be queried using sdparm. Use sdparm --get=WCE to check whether the write cache is enabled and sdparm --clear=WCE to disable it.
The previous paragraph does say "Consumer-grade IDE and SATA drives are particularly likely
   to have write-back caches that will not survive a power failure."

I guess it's reasonable to replace "IDE" with "ATA/SATA" though it's pretty minor. It'd be nice to confirm that the method for disabling the write cache on fbsd is still correct and applies to SATA drives.

--  Craig Ringer                   http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services

Re: doc hdparm also support SATA

From
Peter Eisentraut
Date:
On Sun, 2013-04-07 at 14:29 +0800, Jov wrote:
> from the pg doc：
> http://www.postgresql.org/docs/devel/static/wal-reliability.html :On Linux,
> IDE drives can be queried using hdparm -I; write caching is enabled if
> there is a * next to Write cache. hdparm -W 0 can be used to turn off write
> caching. SCSI drives can be queried using
> sdparm<http://sg.danny.cz/sg/sdparm.html>.
> Use sdparm --get=WCE to check whether the write cache is enabled and sdparm
> --clear=WCE to disable it.
> 
> from the hdparm man page :
> http://linux.die.net/man/8/hdparm :hdparm - get/set SATA/IDE device
> parameters
> 
> so,the doc is out date, it should mention hdparm also support SATA.

done