From: Phillip Susi <psusi@cfl.rr.com>
To: Roberto Spadim <roberto@spadim.com.br>
Cc: "Mathias Burén" <mathias.buren@gmail.com>,
"Eric D. Mudama" <edmudama@bounceswoosh.org>,
"David Brown" <david@westcontrol.com>,
linux-raid@vger.kernel.org
Subject: Re: SSD - TRIM command
Date: Mon, 21 Feb 2011 21:38:07 -0500 [thread overview]
Message-ID: <4D63218F.2000309@cfl.rr.com> (raw)
In-Reply-To: <AANLkTim_F1wqvLprPvytVAMLnbDcr71ys-38WcsFpFkB@mail.gmail.com>
On 02/21/2011 08:55 PM, Roberto Spadim wrote:
> it can be used for badblock reallocation if harddisk have it
> a harddisk is near to NOR ssd with variable accesstime, if head is
> near sector to be read/write accesstime is small, if sector is far
> from head, access time increase (normaly<=1 disk revolution if head
> control system is good, for 7200rpm 1revolution is near to 8.33ms)
Bad blocks are only reallocated when you write to them. Since they are
bad, you can't read the previous contents anyway, so it does not matter
whether the OS cared about it before or not.
You seem to not understand the fundamental purpose of TRIM. Hard disks
only reallocate blocks when they go bad. SSDs move blocks around all
the time. That process can be optimized if the drive knows that the OS
does not care about certain blocks. Hard drives don't do this, so they
have no reason to support TRIM.
next prev parent reply other threads:[~2011-02-22 2:38 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-07 20:07 SSD - TRIM command Roberto Spadim
2011-02-08 17:37 ` maurice
2011-02-08 18:31 ` Roberto Spadim
[not found] ` <AANLkTik5SumqyTN5LZVntna8nunvPe7v38TSFf9eCfcU@mail.gmail.com>
2011-02-08 20:50 ` Roberto Spadim
2011-02-08 21:18 ` maurice
2011-02-08 21:33 ` Roberto Spadim
2011-02-09 7:44 ` Stan Hoeppner
2011-02-09 9:05 ` Eric D. Mudama
2011-02-09 15:45 ` Chris Worley
2011-02-09 13:29 ` David Brown
2011-02-09 14:39 ` Roberto Spadim
2011-02-09 15:00 ` Scott E. Armitage
2011-02-09 15:52 ` Chris Worley
2011-02-09 19:15 ` Doug Dumitru
2011-02-09 19:22 ` Roberto Spadim
2011-02-09 16:19 ` Eric D. Mudama
2011-02-09 16:28 ` Scott E. Armitage
2011-02-09 17:17 ` Eric D. Mudama
2011-02-09 18:18 ` Roberto Spadim
2011-02-09 18:24 ` Piergiorgio Sartor
2011-02-09 18:30 ` Roberto Spadim
2011-02-09 18:38 ` Piergiorgio Sartor
2011-02-09 18:46 ` Roberto Spadim
2011-02-09 18:52 ` Roberto Spadim
2011-02-09 19:13 ` Piergiorgio Sartor
2011-02-09 19:16 ` Roberto Spadim
2011-02-09 19:21 ` Piergiorgio Sartor
2011-02-09 19:27 ` Roberto Spadim
2011-02-21 18:24 ` Phillip Susi
2011-02-21 18:30 ` Roberto Spadim
2011-02-09 15:49 ` David Brown
2011-02-21 18:20 ` Phillip Susi
2011-02-21 18:25 ` Roberto Spadim
2011-02-21 18:34 ` Phillip Susi
2011-02-21 18:48 ` Roberto Spadim
2011-02-21 18:51 ` Mathias Burén
2011-02-21 19:32 ` Roberto Spadim
2011-02-21 19:38 ` Mathias Burén
2011-02-21 19:39 ` Mathias Burén
2011-02-21 19:43 ` Roberto Spadim
2011-02-21 20:45 ` Phillip Susi
2011-02-21 19:39 ` Roberto Spadim
2011-02-21 19:51 ` Doug Dumitru
2011-02-21 19:57 ` Roberto Spadim
2011-02-21 20:47 ` Phillip Susi
2011-02-21 21:02 ` Mathias Burén
2011-02-21 22:52 ` Roberto Spadim
2011-02-21 23:41 ` Mathias Burén
2011-02-21 23:42 ` Mathias Burén
2011-02-21 23:52 ` Roberto Spadim
2011-02-22 0:25 ` Mathias Burén
2011-02-22 0:30 ` Brendan Conoboy
2011-02-22 0:36 ` Eric D. Mudama
2011-02-22 1:46 ` Roberto Spadim
2011-02-22 1:52 ` Mathias Burén
2011-02-22 1:55 ` Roberto Spadim
2011-02-22 2:01 ` Eric D. Mudama
2011-02-22 2:02 ` Mikael Abrahamsson
2011-02-22 2:22 ` Guy Watkins
2011-02-22 2:27 ` Roberto Spadim
2011-02-22 3:45 ` NeilBrown
2011-02-22 4:37 ` Roberto Spadim
2011-02-22 2:38 ` Phillip Susi [this message]
2011-02-22 3:29 ` Roberto Spadim
2011-02-22 3:42 ` Roberto Spadim
2011-02-22 4:04 ` Phillip Susi
2011-02-22 4:30 ` Roberto Spadim
2011-02-22 14:45 ` Phillip Susi
2011-02-22 17:15 ` Roberto Spadim
2011-02-22 0:32 ` Eric D. Mudama
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