Re: OpenBSD and solid state disks
At least with a total failure you know something is wrong, whereas with a functioning but flaky SSD, you could be experiencing a slow drip of bit rot. I guess that this is another possible reason to avoid TLC and QLC drives. Dave On 11/8/19, Chris Cappuccio wrote: > Raymond, David [david.raym...@nmt.edu] wrote: >> Thanks for the insight on SSDs -- sounds like there is not much of an >> issue with modern drives. >> > > If write endurance is a concern, you can buy higher grade SSDs that have > constant latency (at the expense of max speed) and a lot of extra flash. > I would avoid the TLC drives for servers and the QLC drives for everything, > if writes are heavy. > > My biggest problem with SSDs has been total failures. I run pairs of SSDs > in softraid RAID 1 for this reason. > -- David J. Raymond david.raym...@nmt.edu http://physics.nmt.edu/~raymond
Re: OpenBSD and solid state disks
Raymond, David [david.raym...@nmt.edu] wrote: > Thanks for the insight on SSDs -- sounds like there is not much of an > issue with modern drives. > If write endurance is a concern, you can buy higher grade SSDs that have constant latency (at the expense of max speed) and a lot of extra flash. I would avoid the TLC drives for servers and the QLC drives for everything, if writes are heavy. My biggest problem with SSDs has been total failures. I run pairs of SSDs in softraid RAID 1 for this reason.
Re: OpenBSD and solid state disks
On 4/11/19 8:13 am, Raymond, David wrote: > Thanks for the insight on SSDs -- sounds like there is not much of an > issue with modern drives. Well, you're at the mercy of the SSD firmware to "do the right thing" and move the data around to ensure even wear levelling. Most do. The fact that you see SSDs on the consumer market that have 3 and 5 year warranties on them (the 2TB Samsung in my laptop at home had a 10 year warranty), suggests the manufacturers are either highly confident their product will last (or at least confident their disclaimers will let them off the hook). In the last few years I've had a couple of SD cards wear out, and one Intel 240GB SSD fail prematurely (it had a 3 year warranty, was about 12 months old at the time). I had some fun initially claiming the warranty of the Intel as they wanted a report from their Windows-only tool (hopefully their engineering team have seen fit to produce a stand-alone bootable version). I was able to provide reports from `smartctl` on Linux. After I pointed out that I didn't have Windows on this machine (and that if I did, it would have gone up in smoke with the SSD failing), they accepted this and replaced the faulty drive without further issues. Like any storage technology, SSDs are not infallible. Back up the data you wish to keep regularly, and test your back-ups. -- Stuart Longland (aka Redhatter, VK4MSL) I haven't lost my mind... ...it's backed up on a tape somewhere.
Re: OpenBSD and solid state disks
Thanks for the insight on SSDs -- sounds like there is not much of an issue with modern drives. Dave Raymond On 11/3/19, gwes wrote: > On 11/2/19 4:10 PM, Raymond, David wrote: >> I recently installed OpenBSD on a Lenovo X1 Carbon with a solid state >> drive and it works great. >> >> My question is whether OpenBSD addresses the special characteristics >> of solid state drives, especially those having to do with longevity >> and reliability. I can't find anything written on this. Linux has >> certain means for addressing this issue, such as fstrim as well as >> various kernel options. Is there anything I have missed with OpenBSD >> on this subject? >> >> Dave Raymond >> > Any modern drive will have write levelling. Check the rated number > of writes for the drive. Run iostat for a week or two to determine > average writes/time interval. Compare that against 10% of rated > writes. When you get there, replace the drive. > > 500 TB is a good number for write endurance. > Completely writing a 1TB drive every day gives you 50 days. > Writing 100GB a day gives you 500 days... > Do you write 20 DVDs a day? That's your answer. > > Geoff Steckel > > -- David J. Raymond david.raym...@nmt.edu http://physics.nmt.edu/~raymond
Re: OpenBSD and solid state disks
On 11/2/19 4:10 PM, Raymond, David wrote: I recently installed OpenBSD on a Lenovo X1 Carbon with a solid state drive and it works great. My question is whether OpenBSD addresses the special characteristics of solid state drives, especially those having to do with longevity and reliability. I can't find anything written on this. Linux has certain means for addressing this issue, such as fstrim as well as various kernel options. Is there anything I have missed with OpenBSD on this subject? Dave Raymond Any modern drive will have write levelling. Check the rated number of writes for the drive. Run iostat for a week or two to determine average writes/time interval. Compare that against 10% of rated writes. When you get there, replace the drive. 500 TB is a good number for write endurance. Completely writing a 1TB drive every day gives you 50 days. Writing 100GB a day gives you 500 days... Do you write 20 DVDs a day? That's your answer. Geoff Steckel
Re: OpenBSD and solid state disks
On 2019-11-02 16:10, Raymond, David wrote: > I recently installed OpenBSD on a Lenovo X1 Carbon with a solid state > drive and it works great. yep. > My question is whether OpenBSD addresses the special characteristics > of solid state drives, especially those having to do with longevity > and reliability. Just Use them, and plan on replacing them when they need to be replaced, or at least demoting them to "when this fails, I won't cry" uses. In other words, treat them JUST LIKE EVERY OTHER DRIVE. If I hand you a five year old magnetic drive, would you put it in a mission critical application? Probably not. If you have five year old hardware in a mission critical application, you should be looking at replacement. Treat your SSDs exactly the same way, you will have no problems. Used very hard, SSDs last many years. Used like most people use a laptop, you will be replacing for other reasons (capacity, hw it is in is uselessly old, etc.) long before the drives wear out. The obsession with SSD write fatigue is silly. All drives can (and do) fail, you must have a plan to deal with that, and in my experience with SSDs, write fatigue is NOT the primary killer, it's just a predictable one. Nick.
Re: OpenBSD and solid state disks
On 2019-11-02, Raymond, David wrote: > I recently installed OpenBSD on a Lenovo X1 Carbon with a solid state > drive and it works great. > > My question is whether OpenBSD addresses the special characteristics > of solid state drives, especially those having to do with longevity > and reliability. I can't find anything written on this. Linux has > certain means for addressing this issue, such as fstrim as well as > various kernel options. Is there anything I have missed with OpenBSD > on this subject? > > Dave Raymond > Trim doesn't seem hugely necessary with modern SSDs. We do regular bulk port builds on SSD machines (often 4+ times a week for i386/amd64) without anything special and they seem to cope ok. I think https://www.reddit.com/r/openbsd/comments/9h231o/comment/e6bw9ig is valid.
Re: OpenBSD and solid state disks
[...] > My question is whether OpenBSD addresses the special characteristics > of solid state drives, especially those having to do with longevity > and reliability. I can't find anything written on this. Linux has > certain means for addressing this issue, such as fstrim as well as > various kernel options. Is there anything I have missed with OpenBSD > on this subject? I'm certainly not one to reply to this question on the raw metal/filesystem level, but I can assure you that I have used OpenBSD on SSDs (in different computers) for several years by now without noticing any of the scares that circulate about SSDs (those seem to be mainly filesystem corruption and/or significant slowdown). Some of the concerns may simply go back to early generations of SSD drives. I recall that tedu@ discussed SSDs and these matters on his flak blog previously that may contain more details and possibly reassurance for you. Mounting with softdep seems to be advisable. I'm happy to be complemented or corrected by someone with more in-depth knowledge of the low-level aspects of SSDs.
OpenBSD and solid state disks
I recently installed OpenBSD on a Lenovo X1 Carbon with a solid state drive and it works great. My question is whether OpenBSD addresses the special characteristics of solid state drives, especially those having to do with longevity and reliability. I can't find anything written on this. Linux has certain means for addressing this issue, such as fstrim as well as various kernel options. Is there anything I have missed with OpenBSD on this subject? Dave Raymond -- David J. Raymond david.raym...@nmt.edu http://physics.nmt.edu/~raymond
