Re: RAID5 - 2nd drive died whilst waiting for RMA

Re: RAID5 - 2nd drive died whilst waiting for RMA

[David Greaves]

Brad Campbell wrote:

> David Greaves wrote:
>
>> Now all I need is SMART through libata.
>
>
> If you are using a UP system, grab the patches from Jeff's libata-dev 
> tree and have at it.
> I have been beating it hard on 14 drives here on a loaded working 
> server for weeks and have not managed to toast anything yet. It's 
> great being able to keep tabs on the remaining whirly bits and 
> hopefully get an early warning before they expire.
>
> (Fingers crossed. 12 of them are Maxtor Maxline-II drives but all sit 
> between 35 & 40 deg C)
>
> Brad

Thanks Brad
I've been tracking this on the ide list and I've been nervous of 
applying anything since I don't have proper  backups. I'm relying on 
redundancy.

I also found this comment by Jeff on some patches:
  As I noted in another email, be careful...  that patch bypasses the 
SCSI command synchronization, so you could potentially send a SMART 
command to the hardware while another command is still in progress.
He follows up by saying this *will* result in corruption.

And although I *think* he was refering to an earlier incarnation...

I looked to see what I'd need to do and given I'm running 2.6.9 I take 
it I'd have to apply:
  
http://www.kernel.org/pub/linux/kernel/people/jgarzik/libata/2.6.9-libata1-dev1.patch.bz2
which depends on
  
http://www.kernel.org/pub/linux/kernel/people/jgarzik/libata/2.6.9-libata1.patch.bz2

That seems like quite a lot and I'm not clear on the level of stability 
impact on my system.

Now although I track linux-ide I doubt I'm fully informed!!
So if anyone would like to inform me of a reasonable course of action 
then I'm actually reasonably happy to apply the SMART patch.

David

Re: RAID5 - 2nd drive died whilst waiting for RMA

[Måns Rullgård]

David Greaves <david@dgreaves.com> writes:

> I've been tracking this on the ide list and I've been nervous of
> applying anything since I don't have proper  backups. I'm relying on
> redundancy.

RAID can *never* replace proper backups.  RAID only protects against
low-level disk failures.  Filesystem corruption caused by bugs,
accidental deleting of files, etc. are happily allowed.  Get a DVD
burner, you'll thank yourself one day.

-- 
Måns Rullgård
mru@inprovide.com

Re: RAID5 - 2nd drive died whilst waiting for RMA

[Brad Campbell]

Måns Rullgård wrote:
> David Greaves <david@dgreaves.com> writes:
> 
> 
>>I've been tracking this on the ide list and I've been nervous of
>>applying anything since I don't have proper  backups. I'm relying on
>>redundancy.
> 
>
> RAID can *never* replace proper backups.  RAID only protects against
> low-level disk failures.  Filesystem corruption caused by bugs,
> accidental deleting of files, etc. are happily allowed.  Get a DVD
> burner, you'll thank yourself one day.
> 

Heh. I have 2.5TB here. Thats a lot of DVD's.
I have the whole lot set chmod a-w and rely on RAID to keep me alive. (Having said it is a home 
entertainment system and would not cause mega dollar industrial damage if I lost it). All my 
original media is about 9,000km away but I could survive until I re-ripped it.

I slide my array drives out and slide in some throwaway spares to beat on for testing before I 
deploy a new kernel.

David Greaves wrote:

> 
> I looked to see what I'd need to do and given I'm running 2.6.9 I take it I'd have to apply:
>  
> http://www.kernel.org/pub/linux/kernel/people/jgarzik/libata/2.6.9-libata1-dev1.patch.bz2
> which depends on
>  
> http://www.kernel.org/pub/linux/kernel/people/jgarzik/libata/2.6.9-libata1.patch.bz2
> 
> That seems like quite a lot and I'm not clear on the level of stability impact on my system.
> 
> Now although I track linux-ide I doubt I'm fully informed!!
> So if anyone would like to inform me of a reasonable course of action then I'm actually reasonably happy to apply the SMART patch.

That is pretty close. I actually just cloned the kernel bk tree and pulled both of Jeffs trees, but 
then I ran about 10 hours of super intensive tests with 5 spare drives spread across my 3 
controllers before I slid my 13 raid disks back in and let it loose. I guess my real kernel version 
is somewhere around 2.6.10-rc1-bk3.

Have had good luck with it over the last couple of weeks and I have been hitting it pretty hard. 
But, as I said before, I'm on a UP machine. Andy pointed out some possible issues on SMP so beware 
there.

Brad
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Re: RAID5 - 2nd drive died whilst waiting for RMA

[David Greaves]

Måns Rullgård wrote:

>David Greaves <david@dgreaves.com> writes:
>  
>
>>I've been tracking this on the ide list and I've been nervous of
>>applying anything since I don't have proper  backups. I'm relying on
>>redundancy.
>>    
>>
>RAID can *never* replace proper backups.  RAID only protects against
>low-level disk failures.  Filesystem corruption caused by bugs,
>accidental deleting of files, etc. are happily allowed.  Get a DVD
>burner, you'll thank yourself one day.
>  
>
Got one.
I have 935Gb of data (soon to be 1.2Tb)
Each DVD holds 4.7Gb and takes 20-30 mins to burn.
Any other ideas ? ;)

David

PS Seriously - the data is films, my CDs, DVDs, TV shows and the like. 
It's a bummer to lose but in the grand scheme of things it's only the telly.
My _real_ personal data (photos etc) are mirrored onto physically 
seperate disks each night. The 'backups' are remounted read-only. It's 
the 'rsync snapshot' method.

See: http://www.mikerubel.org/computers/rsync_snapshots/

Thanks for your concern though :)