Re: [tlug] Making better use of SSDs?

[Attila Kinali <attila@example.com>]

On Tue, 29 May 2012 09:23:35 +0900
Edward Middleton <edward.middleton@example.com> wrote:

> > BTRFS is cool and i'd like to use it. But it will probably take
> > them another 5 years to get it prime time ready.
> 
> After the discussion of btrfs last time I tried a raid1 partition with 
> btrfs.  It seemed that the major issues people were having occurred when 
> they had power failures[1], kernel crashes or hardware failures.

Yes, a lot of grief comes from crashes. But it's also true that upgrading
kernels or changing configurations of the filesystem tends to corrupt the
fs to the point where you cannot mount it anymore.

>  If you 
> are using it as a scratch space then this may be less of an issue. i.e. 
> if your data can be easily regenerated and you are just using it for 
> improved io.  Is anyone having issues with slow corruption of btrfs 
> data?  I would have thought with block checksums[2] it would be more 
> reliable then other filesystem in this regard.


It's more tollerant against bad blocks or read errors. But that doesn't
mean that it's tollerant to bugs in the code that corrupt the FS.
I am not aware of anyone having "slow corruptions" but i'm not reading
the mailinglist (don't have the time) and only occasional have a look
into the irc channel. But there is quite often someone who has fried
his FS due to something that should not screw it. The lack of an fsck
utility also is a problem in those cases.

> 1. thats what a ups is for.

I don't know when last time power was the cause of a crash... 
probably 5 to 10y ago... In the mean time i had at least a dozen crashes
per year due to misbihaving hardware, driver bugs, kernel VM bugs and
other stuff of that kind. (note that the amount of kernel bugs i hit
is a lot higher than the average... some people call it even the 
"kinali linux curse")

				Attila Kinali

-- 
The trouble with you, Shev, is you don't say anything until you've saved
up a whole truckload of damned heavy brick arguments and then you dump
them all out and never look at the bleeding body mangled beneath the heap
		-- Tirin, The Dispossessed, U. Le Guin