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Effect of turning off LVM bad block relocation on a RAID 0+1 XP1024 array

 
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David Fu_2
Occasional Contributor

Effect of turning off LVM bad block relocation on a RAID 0+1 XP1024 array

Hi,

This may be a repeat question but I searched high and low on ITRC with zilch results.
I was wondering if it was necessary to use bad block relocation on LVM on a RAID 0+1 array?

Here it goes:
Has anyone ever implemented lvm with bad block relocation turned off (-r N)?

What is the resulting effect of bad blocks appearing on a RAID1 volume and how would that affect the data integrity? Would it suffice to let the RAID hardware handle it?

What's your recommendation on it for hardware RAID 0+1 volumes? Leave it on or ok to turn it off?

Would appreciate your insight and answers.

A Happy New Year to you all!
3 REPLIES 3
Thierry Poels_1
Honored Contributor
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Re: Effect of turning off LVM bad block relocation on a RAID 0+1 XP1024 array

Hi,

for intelligent disk arrays like the XP, EVA, EMC², ... bad block relocation should be turned OFF. Bad blocks will be handled by the hardware, no need handle this on LVM level.

regards,
Thierr
All unix flavours are exactly the same . . . . . . . . . . for end users anyway.
David Fu_2
Occasional Contributor

Re: Effect of turning off LVM bad block relocation on a RAID 0+1 XP1024 array

Hi Thierr,

Thanks for the info!

I don't supppose you would know of any tech support doc that has more on this for the XP?
With VA and EMC, I found serveral links to either business support note or technical knowledge docs.

The XP was casually mentioned in certain places but without solid documentation backing. ;P

Happy New Year!
Tom Danzig
Honored Contributor

Re: Effect of turning off LVM bad block relocation on a RAID 0+1 XP1024 array

Bad block relocation should be turned off for the XP disk arrarys. This comes straight form top notch HP-CE when our XP512 was set up.

I also remember reading this as well in XP512 setup and configuration documentation. I don't currently have these doc's available to confirm though.