LinuxQuestions.org
Visit the LQ Articles and Editorials section
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Distributions > Slackware
User Name
Password
Slackware This Forum is for the discussion of Slackware Linux.

Notices



Reply
 
Search this Thread
Old 09-15-2012, 07:15 PM   #16
jtsn
Member
 
Registered: Sep 2011
Location: Europe
Distribution: Slackware
Posts: 908

Rep: Reputation: 447Reputation: 447Reputation: 447Reputation: 447Reputation: 447

Quote:
Originally Posted by TobiSGD View Post
OK, I shouldn't have said physical sector size, but flash block erase boundaries. Those are usually between 128K-512K and are those that have the performance impact when writing to the SSD. Partitions should be aligned to this erase boundaries
SSD controllers don't export these boundaries to the user space. There is no 1:1 mapping, because this would incur a heavy read-modify-write penalty. So you can't align partitions to erase block boundaries anyway.

If you randomly write a 4K sector anywhere on a SSD, it of course lands in a completely different erase block on the flash, than the sector before and behind it.
 
Old 09-16-2012, 09:56 AM   #17
TobiSGD
Moderator
 
Registered: Dec 2009
Location: Hanover, Germany
Distribution: Main: Gentoo Others: What fits the task
Posts: 15,653
Blog Entries: 2

Rep: Reputation: 4095Reputation: 4095Reputation: 4095Reputation: 4095Reputation: 4095Reputation: 4095Reputation: 4095Reputation: 4095Reputation: 4095Reputation: 4095Reputation: 4095
So how do you explain the massive performance impact on SSDs that don't have aligned partitions?
 
Old 09-16-2012, 11:02 AM   #18
pan64
Guru
 
Registered: Mar 2012
Location: Hungary
Distribution: debian i686 (solaris)
Posts: 5,159

Rep: Reputation: 1364Reputation: 1364Reputation: 1364Reputation: 1364Reputation: 1364Reputation: 1364Reputation: 1364Reputation: 1364Reputation: 1364Reputation: 1364
here is a small explanation: http://superuser.com/questions/39391...ould-i-need-it
 
1 members found this post helpful.
Old 09-17-2012, 08:04 AM   #19
jtsn
Member
 
Registered: Sep 2011
Location: Europe
Distribution: Slackware
Posts: 908

Rep: Reputation: 447Reputation: 447Reputation: 447Reputation: 447Reputation: 447
Quote:
Originally Posted by TobiSGD View Post
So how do you explain the massive performance impact on SSDs that don't have aligned partitions?
You have to align them to 4K (8 logical sectors) just like advanced format hard disks. Of course, 1M (2048 logical sectors) works too, because 2048 is a multiple of 8.
 
Old 02-06-2013, 03:39 AM   #20
wubai
Member
 
Registered: Dec 2009
Posts: 103

Rep: Reputation: 20
does that mean I have to remove all data and rewrite all partition ?
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
WD20EARS - smartctl is reporting 4K physical sector size ^^ Orangutanklaus Linux - Hardware 3 09-19-2011 10:36 AM
Should a bootable partition start from sector 1 on a hard disk? citizen22445 Linux - Newbie 2 12-20-2010 07:36 PM
fdisk -ul why does first partition start at sector 63? nickamon Linux - Newbie 3 07-17-2009 05:05 PM
need partition to end on cylinder boundary Master of Reality Linux - General 5 02-03-2006 10:51 PM
Partition does not end on cylinder boundary. snisheeth Linux - Hardware 0 01-24-2004 05:49 PM


All times are GMT -5. The time now is 12:29 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration