[linux-lvm] Disk crash on LVM

Tue Sep 22 13:43:52 UTC 2009

Hello again,

Is there any way to see how much the total progress of pvmove is? I now have 
issued the command 7-8 times with different amount of progress. And I have 
no idea how much is remaining of the total.

Thanks
/Fredrik

----- Original Message ----- 
From: "Fredrik Skog" <fredrik.skog at rodang.se>
To: "LVM general discussion and development" <linux-lvm at redhat.com>
Sent: Tuesday, September 22, 2009 3:27 PM
Subject: Re: [linux-lvm] Disk crash on LVM

> Hi
>
> I'll update you on the progress with my crashed hd.
> I'm not yet finished with the pvmove from the device because it won't work 
> for very long at a time.
> If I have the drive in room temperature and then put it in the freezer for 
> 25-30mins it works for maybe 15-20min (the drive still in the freezer)and 
> i get a pvmove progress of about 15-20%.
> If I then shut it down and just let it cool again I get maybe 5-7% more 
> out of it before it dies.Prolonging the time in the freezer doesn't seem 
> to help at all, in fact sometimes it's worse and the drive doesn't start 
> at all. The drive seems to need a few hours warm-up time after it's been 
> frozen and then stopped working before I can refreeze it again.
> It takes ridiculous amounts of time fiddling with this, but I hope to get 
> to the finish soon.
> I have not yet tried to increase the readahead.
>
> /Fredrik
>
>
> ----- Original Message ----- 
> From: "Peter Keller" <pkeller at globalphasing.com>
> To: "LVM general discussion and development" <linux-lvm at redhat.com>
> Sent: Monday, September 21, 2009 1:27 PM
> Subject: Re: [linux-lvm] Disk crash on LVM
>
>
>> Coming a bit late to this thread...
>>
>> On Sat, 19 Sep 2009, Fredrik Skog wrote:
>>
>>> Thanks guys for your input on the matter.
>>> I lenghtened the power cables and bought a full lenght SATA cable. Now 
>>> the
>>> disk is in the freezer and in progress with pvmove. 10% now. so far so 
>>> good.
>>> The reason i decided for the pvmove instead of dd or dd_rescue was the 
>>> fact
>>> that i tried a pvmove before, so the process was already started but it
>>> stopped working on 1%. Now with a frozen and working disk it continued 
>>> from
>>> where it left off.
>>
>> I have found that with sequential reads like this, adjusting the 
>> readahead
>> of the device with something like 'blockdev --setra nnn' can dramatically
>> shorten the time needed to read the whole device.
>>
>> The default usually seems to be too low when reading sequentially. If you
>> haven't already adjusted it, try adjusting it upwards. Values like 8192 
>> or
>> 16384 may help.
>>
>> Good luck,
>> Peter.
>>
>>> I can tell you how it turned out later.
>>>
>>> Thanks
>>>
>>> /Fredrik
>>>
>>>
>>>
>>> ----- Original Message ----- From: "André Gillibert" <rcvxdg at gmail.com>
>>> To: <linux-lvm at redhat.com>
>>> Sent: Saturday, September 19, 2009 4:11 PM
>>> Subject: Re: [linux-lvm] Disk crash on LVM
>>>
>>>
>>>> Ray Morris <support at bettercgi.com> wrote:
>>>>> [...]
>>>>>    Then dd from the old copy of the LV to the new:
>>>>>
>>>>> dd if=/dev/org/$1 bs=64M iflag=direct |
>>>>> dd of=/dev/copy/$1 bs=64M oflag=direct
>>>>>
>>>>>    That piped dd is 2-3 times faster than the "obvious"
>>>>> way to run dd.
>>>>> [...]
>>>>
>>>> The issue with dd is that if any read() fails, it skips the entry (64M) 
>>>> and
>>>> doesn't write to the output, making the output file smaller than the 
>>>> input
>>>> file.
>>>>
>>>> with conv=sync,noerror, it's better, but, still loosing a whole 64M 
>>>> block
>>>> at once is a bad thing.
>>>>
>>>> That's why I think dd_rescue would be better.
>>>> <http://www.garloff.de/kurt/linux/ddrescue/>
>>>>
>>>> If it still gets warm too fast, I've heard that storing the hard drive 
>>>> in a
>>>> freezer 24 hours may make it work again.
>>>> <http://geeksaresexy.blogspot.com/2006/01/freeze-your-hard-drive-to-recover-data.html>
>>>>
>>>> If it crashes when dd or dd_rescue fails, it's possible to continue 
>>>> copying
>>>> later, from the point it failed.
>>>>
>>>> -- 
>>>> André Gillibert
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> linux-lvm mailing list
>>>> linux-lvm at redhat.com
>>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>
>>> _______________________________________________
>>> linux-lvm mailing list
>>> linux-lvm at redhat.com
>>> https://www.redhat.com/mailman/listinfo/linux-lvm
>>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>>
>>
>> -- 
>> Peter Keller                                     Tel.: +44 (0)1223 353033
>> Global Phasing Ltd.,                             Fax.: +44 (0)1223 366889
>> Sheraton House,
>> Castle Park,
>> Cambridge CB3 0AX
>> United Kingdom
>
>
> --------------------------------------------------------------------------------
>
>
>> _______________________________________________
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>> linux-lvm at redhat.com
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>
> _______________________________________________
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> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ 