Re: FFS parameters for SSD filesystem?
On 03/09/17 15:20, Christian Weisgerber wrote: > On 2017-03-09, Jonathan Thornburg <jthorn4...@gmail.com> wrote: > >> Subject: FFS parameters for SSD filesystem? > > You are overthinking this. The defaults are fine. What he said. An SSD is a SATA storage device. It's the 2010s. JUST USE IT. Knob twisting for file systems went out with the 1990s. It will either give you trouble in the first weeks or last until long after you are laughing at how small a 1TB of storage is, how big a 2.5" disk is, and how slow the SATA interface is. FFS2 is nice for big storage areas, but NOTHING to do with SSD or non-SSD. (ok, update the firmware for your SSD. that's something that should have stopped after the 1990s, too, but surprise: the computer industry sells crap and you line up to buy it. I've had that exact disk give me trouble that seems to have settled down by dd'ing zeros over entire partitions before using them. Your milage may vary.) Nick.
Re: FFS parameters for SSD filesystem?
On 2017-03-09, Jonathan Thornburg <jthorn4...@gmail.com> wrote: > Subject: FFS parameters for SSD filesystem? You are overthinking this. The defaults are fine. -- Christian "naddy" Weisgerber na...@mips.inka.de
Re: FFS parameters for SSD filesystem?
On Thu, Mar 09, 2017 at 12:08:56PM -0500, Jonathan Thornburg wrote: > Hi, > > I'm preparing to set up a new 1TB SSD (Samsung 850pro) for use in an > OpenBSD laptop. Like every other SSD I've seen, this SSD uses a 4K > byte block size. > > I'm planning to use softraid crypto for this disk, and mount all the > main filesystems with softdep and noatime. > > I understand that fdisk and disklabel partition boundaries should > be multiples of 4K bytes (= 8 512-byte sectors), e.g., starting the > 'a' disklabel partition at offset=64 512-byte sectors is much better > than starting it at offset=63. > > I've read the misc@ thread on "4k sector disks" from 2010, > http://marc.info/?l=openbsd-misc=127071305915101=1 > http://marc.info/?l=openbsd-misc=127149466227162=1 > tedu's 2011 blog post "lessons learned about TRIM", > http://www.tedunangst.com/flak/post/lessons-learned-about-TRIM > and the 2014 daemonforums thread on SSD installs, > http://daemonforums.org/showthread.php?t=8630 > > Questions: > * Should I set the FFS fragment size (newfs -f) to 4096 or larger? Don't think it is needed to set manyally, should be handled automatically. > * What about the FFS sector size (newfs -S): should this be left at > its default, or set to 4096? Default will be 4096 on a 4k disk. > * Are there other fdisk and/or newfs parameters which should be set > differently than I'd set them for a mechanical hard disk of similar > size? Nope. > * What are the tradeoffs between FFS (newfs -O 1) and FFS2 (newfs -O 2)? > Since this is OpenBSD, perhaps I should rephrase this question as > "what Fine Manual should I have read to learn about these tradeoffs?" If you have large partitions Lets say > 100G), go for -O2. Saves quite some time. If you plan to store many large files and few small files, go for a larger blocksize (and possibly fragment size). > * Does or should using softraid crypto change the answers to any of > the above questions? Cannot tell that, -Otto
FFS parameters for SSD filesystem?
Hi, I'm preparing to set up a new 1TB SSD (Samsung 850pro) for use in an OpenBSD laptop. Like every other SSD I've seen, this SSD uses a 4K byte block size. I'm planning to use softraid crypto for this disk, and mount all the main filesystems with softdep and noatime. I understand that fdisk and disklabel partition boundaries should be multiples of 4K bytes (= 8 512-byte sectors), e.g., starting the 'a' disklabel partition at offset=64 512-byte sectors is much better than starting it at offset=63. I've read the misc@ thread on "4k sector disks" from 2010, http://marc.info/?l=openbsd-misc=127071305915101=1 http://marc.info/?l=openbsd-misc=127149466227162=1 tedu's 2011 blog post "lessons learned about TRIM", http://www.tedunangst.com/flak/post/lessons-learned-about-TRIM and the 2014 daemonforums thread on SSD installs, http://daemonforums.org/showthread.php?t=8630 Questions: * Should I set the FFS fragment size (newfs -f) to 4096 or larger? * What about the FFS sector size (newfs -S): should this be left at its default, or set to 4096? * Are there other fdisk and/or newfs parameters which should be set differently than I'd set them for a mechanical hard disk of similar size? * What are the tradeoffs between FFS (newfs -O 1) and FFS2 (newfs -O 2)? Since this is OpenBSD, perhaps I should rephrase this question as "what Fine Manual should I have read to learn about these tradeoffs?" * Does or should using softraid crypto change the answers to any of the above questions? Thanks, -- -- "Jonathan Thornburg [remove -color to reply]"Dept of Astronomy & IUCSS, Indiana University, Bloomington, Indiana, USA "There was of course no way of knowing whether you were being watched at any given moment. How often, or on what system, the Thought Police plugged in on any individual wire was guesswork. It was even conceivable that they watched everybody all the time." -- George Orwell, "1984"