Samsung SSD-830, System Freezing and Reinstalling

[fleerink]

Hallo

A year ago I have added a Samsung SSD-830 to my system,with a Core I3 CPU-530 and 4 GB Memory. At the same time I removed Windows 7 from the existing HD of 930GB and reformatted that as a single EXT4 /data partition and installed openSUSE 12.3 on the SSD. The partition set up is as follows:

/dev/sda 930 GB
/dev/sda1 900 GB Ext4 /data

/dev/sdb 238 GB
/dev/sdb1 20 GB EXT4 /
/dev/sdb2 80 GB EXT4 /home
/dev/sdb3 138 GB Extended
/dev/sdb5 2 GB Linux swap swap
/sev/sdb6 20 GB EXT4 not mounted (/ for openSUSE 13.1)
/dev/sdb7 30 GB EXT4 not mounted (/home for openSUSE 13.1)

The install went ok and the system function normally although the initial startup was not so fast as expected.
Around year end I have installed openSUSE 13.1 in the sdb6 and 7 partitions, first to test the system and later set as my main system.

A month or 2 ago I experienced that the mouse (or system) started to freeze, I could only continue by pressing the power button and boot-up again.
Slowly these symptoms became more frequent, replacing my mouse did not help and finally the system freeze every 1-3 hour.

Checking the logs, googling around does not point to the problem. Finally I checked with my supplier of the system to turn it in for repair. On the moment
that I told him about the SSD-Drive he say that there are quite some freezing problems with SSD's. He suggested me, before I turn in the system for repair,
to disconnect the SSD and run the system from A live USB stick with the openSUSE 13.1 system to check whether it is a SSD problem.

It turned out to be a problem with the SSD-Drive, since I can normally use the system without the freezing symptoms.

Furher googling learned me that SSD-drives need special set up eg
- Preferably be the first drive
- Changes to the fstab with noatime, discard
- Should not use it for swap file, / and /home

Is there an openSUSE document that describes the set-up / Configuration of SSD-drives ?
Can I reformat/reset the SSD or do I need to do something special ???

Regards, Frans

[gogalthorp]

The problem with SSD's is that they wear out. Every time you write to one it triggers a erase to the block you wrote to. You can only rewrite a block so many times before the flash eats itself. So check it with smartctl if there is no more spare memory left the drive is as good as dead. Note the number of rewrites before disaster depends on a lot of things. Type of flash, the write leveling algorithm on the drive firmware amount of space used amount of memory reserved for spares etc.

These two items are important

- Changes to the fstab with noatime, discard - this stops writing to the file system each time a read happens.
- Should not use it for swap file, / and /home
swap should not be on it because it potential could have lots of rewrites.
/ can be but there are several directories in root that see a lot of rewriting /tmp /var/cache /var/tmp These are best on spinning rust drives and or virtual file systems. Note that if you have a Database on root that expected could have haevy writes on the SSD it would be best to move to a HD
/home may or may not be it depends on how you use things. If you are a developer and constantly compiling and editing programs probably best to keep such files on HD if you just download stuff and it is mostly static it would be ok in a SSD

I know of no reason for a SSD to be the first drive.

Anytime you deal with a new class of hardware you should get all the technical info you can on it before using since little things like the above can bite you. Don't let the hype blind you.

[tsu2]

I've had several conversations with people who manufacture SSD and they all generally say that if it's not defective, today's manufactured models should last reliably and "indefinitely" more or less easily outlasting other components in a typical system. And, certainly not cause problems after a single year.

If you haven't implemented the required settings to avoid write amplification (look it up on Wikipedia), you <will> experience the problems you describe, which is that your system will appear to have no disk space available despite ample reported free space.

As for your thoughts about
- First drive only. That is only because the first drive ordinarily contains the boot and OS files which are read once and hardly ever modified later. SSD is blindingly fast for read-only and <can> write slow, but "slow" should not be too much slower than HDD if you implement SSD optimizations. If you have any other files which are "write once, read thereafter" then SSD is appropriate for that... eg archives, databases used for analysis and search (not LOB typically)
- fstab entries. Yes. Those are critically important. But see my PPT, I also describe how to modify I/O to recognize you're not reading from a rotating disk with variable geometry
- swap. Well, I've seen some recommendations both ways. Depends on the OS, but nowadays with cheap RAM swap should not be accessed that often either. So, if it's not being used except in an emergency I'd say sure, put your swap on SSD.

I recommend a look at the PPT I created years ago for 12.2. When I wrote it, it was at a time that the SSD industry was emerging from the problems of erratic and unreliable manufacturing and optimizations were being re-evaluated for their effectiveness. The various optimizations in my PPT are the basics that maybe accomplish over 98% of what should be done and are just as relevant today as then, nothing needs changing. You can go to the arch Linux SSD pages for further things you can do but IMO anything beyond what I described has very little incremental utility. You can ignore the parts that describe nVidia GPU issues, those were specific to upgrades from 11.x > 12.x.
https://sites.google.com/site/4techs...ntations-30min

HTH,
TSU

[malcolmlewis]

Hi
I'm running btrfs on my SSD's (both OCZ's) but as other have indicated noatime and discard are important. Both my ssd's are also single drive systems so I set the elvators to noop, so if your wanting to implement disk i/o scheduling with an ssd and a rotaing drive there are some udev rules to write. The other thing I do is wind down swappines via some sysctl.conf settings.

I do run /home and swap on these ssd's and on my 128GB (VERTEX 4) device it's writing about ~6.5GB of data a day this drive is rated at 20GB per day, the 60GB (AGILITY 3) device has been running for over 12627 hours and showing no wear at all.

[fleerink]

I've had several conversations with people who manufacture SSD and they all generally say that if it's not defective, today's manufactured models should last reliably and "indefinitely" more or less easily outlasting other components in a typical system. And, certainly not cause problems after a single year.

If you haven't implemented the required settings to avoid write amplification (look it up on Wikipedia), you <will> experience the problems you describe, which is that your system will appear to have no disk space available despite ample reported free space.

As for your thoughts about
- First drive only. That is only because the first drive ordinarily contains the boot and OS files which are read once and hardly ever modified later. SSD is blindingly fast for read-only and <can> write slow, but "slow" should not be too much slower than HDD if you implement SSD optimizations. If you have any other files which are "write once, read thereafter" then SSD is appropriate for that... eg archives, databases used for analysis and search (not LOB typically)
- fstab entries. Yes. Those are critically important. But see my PPT, I also describe how to modify I/O to recognize you're not reading from a rotating disk with variable geometry
- swap. Well, I've seen some recommendations both ways. Depends on the OS, but nowadays with cheap RAM swap should not be accessed that often either. So, if it's not being used except in an emergency I'd say sure, put your swap on SSD.

I recommend a look at the PPT I created years ago for 12.2. When I wrote it, it was at a time that the SSD industry was emerging from the problems of erratic and unreliable manufacturing and optimizations were being re-evaluated for their effectiveness. The various optimizations in my PPT are the basics that maybe accomplish over 98% of what should be done and are just as relevant today as then, nothing needs changing. You can go to the arch Linux SSD pages for further things you can do but IMO anything beyond what I described has very little incremental utility. You can ignore the parts that describe nVidia GPU issues, those were specific to upgrades from 11.x > 12.x.
https://sites.google.com/site/4techs...ntations-30min

HTH,
TSU

Hello,

I have followed your advices and my problem is solved now. The following URL was very helpfull for me:

https://sites.google.com/site/easyli...sd-in-opensuse

Thanks for the help

Regards, Frans

[wakou]

Thanks to https://forums.opensuse.org/member.php/7805-fleerink for this excellent question, and to the usual suspects for the the expert answers. I have more or less precisely similar issues, even down to the brand and model of SSD. I will be looking at https://sites.google.com/site/4techs...ntations-30min with interest, and rejigging my system.

[wakou]

Hello,

I have followed your advices and my problem is solved now. The following URL was very helpfull for me:

https://sites.google.com/site/easyli...sd-in-opensuse

Thanks for the help

Regards, Frans

Was there any sign of permanent damage to the SSD? Did you have to reformat? Or just adjust settings in fstab etc?

[mxcrowe]

From my experience with SSDs (I have a Samsung 840 EVO with Win7 and a Corsair Force GT with OpenSUSE), the general consensus seems to be as TSU said:

if it's not defective, today's manufactured models should last reliably and "indefinitely" more or less easily outlasting other components in a typical system

As reported in another thread on this forum (http://forums.opensuse.org/showthrea...e-to-3-11-10-7) my Corsair drive recently failed, initially with weird results that instigated my post about KDE crashing (which turned out to be more severe than just the desktop), but ultimately with an inability to format the drive and intermittent visibility, even to BIOS. From what I have read, this is definitely not normal. SSDs appear to be fairly long-lived, even when punished, and as they do wear out, they seem to show fairly graceful degradation. This is the picture that emerges from some endurance studies posted here:

http://www.xtremesystems.org/forums/...e-25nm-Vs-34nm

http://techreport.com/review/25559/t...t-200tb-update

I also used the resource that the OP listed (http://sites.google.com/site/easylinuxtipsproject/ssd-in-opensuse) to set up the Corsair in OpenSUSE - this appears to be one of the best guides available for setting up SSDs on Linux and is consistent with most of the advice provided in this thread.