On Mon, 22 Jan 2007, kyle wrote:
> Hi,
>
> Yesterday I tried to increase the value of strip_cache_size to see if I can
> get better performance or not. I increase the value from 2048 to something
> like 16384. After I did that, the raid5 freeze. Any proccess read / write to
> it stucked at D state. I tried to change it back to 2048, read
> strip_cache_active, cat /proc/mdstat, mdadm stop, etc. All didn't return back.
> I even cannot shutdown the machine. Finally I need to press the reset button
> in order to get back my control.
>
> Kernel is 2.6.17.8 x86-64, running at AMD Athlon3000+, 2GB Ram, 8 x Seagate
> 8200.10 250GB HDD, nvidia chipset.
>
> cat /proc/mdstat (after reboot):
> Personalities : [raid1] [raid5] [raid4]
> md1 : active raid1 hdc2[1] hda2[0]
> 6144768 blocks [2/2] [UU]
>
> md2 : active raid5 sdf1[7] sde1[6] sdd1[5] sdc1[4] sdb1[3] sda1[2] hdc4[1]
> hda4[0]
> 1664893440 blocks level 5, 512k chunk, algorithm 2 [8/8] [UUUUUUUU]
>
> md0 : active raid1 hdc1[1] hda1[0]
> 104320 blocks [2/2] [UU]
>
> Kyle
>
> -
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>
Yes, I noticed this bug too, if you change it too many times or change it
at the 'wrong' time, it hangs up when you echo numbr >
/proc/stripe_cache_size.
Basically don't run it more than once and don't run it at the 'wrong' time
and it works. Not sure where the bug lies, but yeah I've seen that on 3
different machines!
Justin.
On Mon, 22 Jan 2007, Steve Cousins wrote:
>
>
> Justin Piszcz wrote:
> > Yes, I noticed this bug too, if you change it too many times or change it at
> > the 'wrong' time, it hangs up when you echo numbr > /proc/stripe_cache_size.
> >
> > Basically don't run it more than once and don't run it at the 'wrong' time
> > and it works. Not sure where the bug lies, but yeah I've seen that on 3
> > different machines!
>
> Can you tell us when the "right" time is or maybe what the "wrong" time is?
> Also, is this kernel specific? Does it (increasing stripe_cache_size) work
> with RAID6 too?
>
> Thanks,
>
> Steve
> --
> ______________________________________________________________________
> Steve Cousins, Ocean Modeling Group Email: [email protected]
> Marine Sciences, 452 Aubert Hall http://rocky.umeoce.maine.edu
> Univ. of Maine, Orono, ME 04469 Phone: (207) 581-4302
>
>
>
The wrong time (for me anyway) is when/or around the time in which kernel
is auto-detecting arrays/udev starts, when I put it there I get OOPSES all
over the screen and it gets really nasty. Basically the best time appears
to be right after the system has started up but I/O hasn't started hitting
the array yet. Tricky, I know.
Justin.
On Mon, 22 Jan 2007, Steve Cousins wrote:
>
>
> Justin Piszcz wrote:
> > Yes, I noticed this bug too, if you change it too many times or change it at
> > the 'wrong' time, it hangs up when you echo numbr > /proc/stripe_cache_size.
> >
> > Basically don't run it more than once and don't run it at the 'wrong' time
> > and it works. Not sure where the bug lies, but yeah I've seen that on 3
> > different machines!
>
> Can you tell us when the "right" time is or maybe what the "wrong" time is?
> Also, is this kernel specific? Does it (increasing stripe_cache_size) work
> with RAID6 too?
>
> Thanks,
>
> Steve
> --
> ______________________________________________________________________
> Steve Cousins, Ocean Modeling Group Email: [email protected]
> Marine Sciences, 452 Aubert Hall http://rocky.umeoce.maine.edu
> Univ. of Maine, Orono, ME 04469 Phone: (207) 581-4302
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
Also, I have not tested the stripe_cache_size under RAID6, I am unsure.
Justin.
Justin Piszcz wrote:
> Yes, I noticed this bug too, if you change it too many times or change it
> at the 'wrong' time, it hangs up when you echo numbr >
> /proc/stripe_cache_size.
>
> Basically don't run it more than once and don't run it at the 'wrong' time
> and it works. Not sure where the bug lies, but yeah I've seen that on 3
> different machines!
Can you tell us when the "right" time is or maybe what the "wrong" time
is? Also, is this kernel specific? Does it (increasing
stripe_cache_size) work with RAID6 too?
Thanks,
Steve
--
______________________________________________________________________
Steve Cousins, Ocean Modeling Group Email: [email protected]
Marine Sciences, 452 Aubert Hall http://rocky.umeoce.maine.edu
Univ. of Maine, Orono, ME 04469 Phone: (207) 581-4302