Re: ssd+3.7 kernel trim: problems, read-only.

* Uwe Brauer <[email protected]> wrote:
> Hello

Hello Uwe,

the fstrim patch was done by me, so solving the problem is maybe also
up to me ;)


> I tried to send this email via gmane, but I never saw it on that list,
> so I resend it.
> 
> 
> 
> Using a Thinkpad Laptop with a new Samsung ssd, I have installed kubuntu
> 10.04 and chosen jfs. Since 10.04 is too old to support trimming, I
> compiled and installed kernel 3.7 and complied fstrim.
> 
> The relevant entry of my fstab reads as follows.
> 
> 
> UUID=8e06979b-2dbf-4192-8513-957bafa74a1e /               jfs
> nodiratime,noatime,errors=remount-ro 0       
> 
> The recommendation to use nodiratime and noatime for ssd I found
> for example in http://askubuntu.com/questions/1400/how-do-i-optimize-the-os-for-ssds
> 
> I run fstrim periodically via cron and everything seems fine.
> 
> However from time to time by system ends up to be mounted *read-only*.
> 
>  dmesg  gives errors like this:
> 
> [105074.721310] ERROR: (device sda5): dbDiscardAG: no memory for trim array
>  
> (I could send the complete result of dmesg, but it is large. I obtained
> it by dmesg | pastebinit).

Could you compress the dmesg output and send me private mail?

Maybe I can reduce the amount of memory needed... also what are the
technical details of your configuration?

Just a small summary, like RAM, CPU, size of partition and so on are
needed, if not already readable in the dmesg output ;)


> 
> Since the fstab entry states errors=remount-ro I presumed this is the
> source for the read only remount.
> 
> I can remount my hard disk and continue as if nothing has happened or I
> can reboot. 

Hm.. I think remounting is okay, not reboot needed...

> 
> In any case I would like to know:
> 
>     -  what can I do to prevent this problem, since it is annoying and
>        might result in  loss.
> 
>     -  is it safe just to remount or should I reboot?

Real details will follow, when I can review the dmesg output ;)


With best regards, Tino


> ------------------------------------------------------------------------------
> Dive into the World of Parallel Programming. The Go Parallel Website,
> sponsored by Intel and developed in partnership with Slashdot Media, is your
> hub for all things parallel software development, from weekly thought
> leadership blogs to news, videos, case studies, tutorials and more. Take a
> look and join the conversation now. http://goparallel.sourceforge.net/

> _______________________________________________
> Jfs-discussion mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/jfs-discussion


-- 
Best regards, TR

------------------------------------------------------------------------------
Dive into the World of Parallel Programming. The Go Parallel Website,
sponsored by Intel and developed in partnership with Slashdot Media, is your
hub for all things parallel software development, from weekly thought
leadership blogs to news, videos, case studies, tutorials and more. Take a
look and join the conversation now. http://goparallel.sourceforge.net/