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Heavy SSD Writes from Firefox

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Re: Heavy SSD Writes from Firefox

#321

Post by bartvk »

matt4077 wrote: post #192
lucb1e wrote: post #84

Earlier quoted context omitted.

Launchpad is such a shitty website, aimed at Ubuntu and only Ubuntu, links to source code or more information are nowhere to be found... Searching on Github, this seems to be it. Turns out, there's releases for Arch, Debian, etc. and it's even in the repositories. No need to add a ppa. https://github.com/graysky2/profile-sync-daemon For Debian and co: $ apt-cache show profile-sync-daemon $ sudo apt-get install profil…

I checked the Activity Monitor on OS X to see if it's the same and if I should do something. It's quite surprising: bird 11,38 GB 119,8 MB kernel_task 8,82 GB 23,0 MB launchd 8,46 GB 77,7 MB revisiond 8,35 GB 105,8 MB Tweetbot 3,01 GB 50,2 MB Safari 879,6 MB 10,0 MB mds_stores 726,2 MB 570,1 MB systemstatsd 695,0 MB 775,0 MB nsurlstorag 685,3 MB 9,5 MB Google Chrom 681,4 MB 303,5 MB iTerm2 653,7 MB 1,6 GB cfprefsd 50…

You can check out what bird does. This Python script showed me that the Whatsapp desktop app was consuming a couple of gig: https://github.com/bwesterb/blame-bird/blob/master/blame-bir...

Re: Heavy SSD Writes from Firefox

#323

Post by acqq »

alexhawke wrote: post #302
Reason077 wrote: post #296

Earlier quoted context omitted.

The warranty on your EVO is just 150 TBW. Yes, but endurance tests almost invariably show that the warranty ratings are extremely conservative. The 1TB 850 PRO (which uses exactly the same NAND chips as the 850 EVO, just a different controller) has been endurance tested to more than 7 Petabytes. See: http://packet.company/blog/ The older generations typically had better endurance, the newer generations are more dense…

No, you're wrong. The 850 PRO uses MLC while the EVO uses TLC. But given that they're both constructed on Samsung's 3D-VNAND technology, their endurance is still much higher than the competitors out there.

> their endurance is still much higher

It's not "much" higher, actually, 3D MLC as implemented by Samsung is just "up to twice" better than the planar MLC given the same die area and capacity:

http://www.samsung.com/semiconductor/minisite/ssd/v-nand/tec...

"Samsung V-NAND provides up to twice the endurance of planar NAND."

But if the size of the cell drops, the number of P/E cycles drops. Samsung's endurance declarations are real and to be believed, they initially used bigger cells than some of their other chips (or competitors), but Samsung engineers know what they do, that "some tests" achieved "much more" can be either an accident or due to the errors in the test methodology (and I very much suspect the later, because it also allows the accidents to be taken as the "success"). At the time these SSDs appeared, Samsung declared twice less TBW than they do now, so now the declared endurance is surely not too pessimistic, but based on the real knowledge of what's inside.

Re: Heavy SSD Writes from Firefox

#324

Post by vsespb »

Yoric wrote: post #126

Hi, I’m one of the Firefox developers who was in charge of Session Restore, so I’m one of the culprits of this heavy SSD I/O. To make a long story short: we are aware of the problem, but fixing it for real requires completely re-architecturing Session Restore. That’s something we haven’t done yet, as Session Restore is rather safety-critical for many users, so this would need to be done very carefully, and with plent…

That's not SSD-only problem. HDD affected too. FF UI is just freezing when using HDD (linux; tried WD RE4, 7200rpm or WD blue 7200 rpm), several years ago I wrote script for myself to keep profile data on RAM disk and sync back to HDD, and problem gone.

Re: Heavy SSD Writes from Firefox

#325

Post by acqq »

acqq wrote: post #265
holygoat wrote: post #249

Earlier quoted context omitted.

15 minutes of coding, perhaps. Then an hour of writing good tests. Then lots of manual and automated testing on four or five platforms, and fixing the weird issues you get on Windows XP SP2, or only on 64-bit Linux running in a VM, or whatever. Then making sure you don't regress startup performance (which you probably will unless you have a really, really slow disk). Then implementing rock solid migration so you can…

> regress startup performance No, for example, LZ4 is unbelievably fast: https://github.com/Cyan4973/lz4 almost 2 GB per second in decompression! I've just tried compressing some backupXX.session file (the biggest I've managed to find, just around 2 MB) and it compressed to 70% of the original, probably not enough to implement the compression -- and I suspect the reason is that the file contains too much base64 encod…

So "somebody" was me at the end, I've rolled up my sleeves and extracted the damn pictures: in my 1.7 MB session file approximately 1 MB were the base64 encodings of exactly 57 jpeg pictures that were all the result of the Google image search (probably of the single search). There were additionally a few pngs, representing "facebook, twitter, gplus" images and one "question mark sign" gif too.

Re: Heavy SSD Writes from Firefox

#326

Post by Reason077 »

alexhawke wrote: post #302
Reason077 wrote: post #296

Earlier quoted context omitted.

The warranty on your EVO is just 150 TBW. Yes, but endurance tests almost invariably show that the warranty ratings are extremely conservative. The 1TB 850 PRO (which uses exactly the same NAND chips as the 850 EVO, just a different controller) has been endurance tested to more than 7 Petabytes. See: http://packet.company/blog/ The older generations typically had better endurance, the newer generations are more dense…

No, you're wrong. The 850 PRO uses MLC while the EVO uses TLC. But given that they're both constructed on Samsung's 3D-VNAND technology, their endurance is still much higher than the competitors out there.

Yes, you're right. But I don't expect an EVO to last for a full 7 PB of writes like the PRO did. But even if it lasts a fraction of that (say, approx 1 PB, which previous generation 840 EVO was able to achieve) then it's still 90 years of life at current usage levels! A (1 TB) 850 PRO would last over 600 years!

In all likelihood the drive will never get anywhere near any of these values - it'll be replaced with newer, better tech at some point. It may then get used for a backups or secondary storage, but in those scenarios the daily writes will drop enormously.

Re: Heavy SSD Writes from Firefox

#327

Post by Reason077 »

sandGorgon wrote: post #315
Reason077 wrote: post #267

Earlier quoted context omitted.

Some people are unjustifiably worried about SSD endurance. The reality is that even with fairly heavy use, most of them will far outlive the computers they're in. And their owners for that matter! I purchased my current SSD in March 2015 - it's a Samsung 850 EVO 512GB. It's done 7332 Power_On_Hours, and 36486573259 Total_LBAs_Written, which works out as just under 17 TB written, or about 31.6 GB/day. That kind of sou…

this is an incorrect assumption http://techreport.com/review/27909/the-ssd-endurance-experim... Most of the SSD failed before a petabyte... and started encountering lots of errors before that (forget about the Samsung Pro series which is the only one that survived till its multi-petabyte end).

Those were all ~250GB devices, however. Endurance increases with higher capcity.

If a 250GB 840 EVO can get to 800TB without errors, then I'd expect a 500GB 850 EVO to reach 1 PB, easily.

A 500GB 850 EVO has newer-generation, more durable NAND endurance and twice the capacity to work with.

Re: Heavy SSD Writes from Firefox

#328

Post by acqq »

Yoric wrote: post #319
acqq wrote: post #272

Earlier quoted context omitted.

Storing a lot of static images as JSON base64 encoded, every 15 seconds is certainly not something that users should be blamed ("some users have 300MB JSON files"), just the poor programming. It would be interesting if somebody would actually analyze what takes the most of the mentioned 300 MB. I see a lot of base64 encoded stuff, if they are "favicons," come-on. There are so many caches in Firefox already, JSON file…

Nobody is blaming the user for the 300Mb. It's just a factor we need to take in consideration. But yeah, storing favicon in Session Restore would be pretty bad. I didn't remember that it was the case, though.

I don't see favicons too, but I've just did one "image extraction" attempt:

https://news.ycombinator.com/item?id=12569999

700 KB of binary images in a 1.7 MB session file, which can be compressed only to the 70% of its size.

I also see a lot of things like \\u0440 which spends eight characters for one unicode character (in another file, not from me). But that file was reduced to 37% of initial size with LZ4. It seems LZ4 is still worth doing, if the content remains easily accessible with the external tools, e.g. lz4cli.

Re: Heavy SSD Writes from Firefox

#329

Post by onnoonno »

marcosdumay wrote: post #271
expression wrote: post #31

Earlier quoted context omitted.

Or ramdisk if you have a stable system.

That would lose the point of a recovery system. I'd rather just turn it off.

I have easily more than 100 firefox crashes for each kernel crash, and I guess that is similar for other people(?)

So I think the session restore is almost always used in a case where firefox crashed, but the system is fine.

Re: Heavy SSD Writes from Firefox

#330

Post by sundarurfriend »

Yoric wrote: post #319
acqq wrote: post #272

Earlier quoted context omitted.

Storing a lot of static images as JSON base64 encoded, every 15 seconds is certainly not something that users should be blamed ("some users have 300MB JSON files"), just the poor programming. It would be interesting if somebody would actually analyze what takes the most of the mentioned 300 MB. I see a lot of base64 encoded stuff, if they are "favicons," come-on. There are so many caches in Firefox already, JSON file…

Nobody is blaming the user for the 300Mb. It's just a factor we need to take in consideration. But yeah, storing favicon in Session Restore would be pretty bad. I didn't remember that it was the case, though.

As an Fx user, I'm glad that favicons are stored though. The icons are a much easier, quicker indicator of what the tab is, when I'm scrolling through dozens of tabs to see which one to click and load.
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