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Two Hotspares with RAID6 and EQL
Hi,
when you configure an EQL array to RAID6, it selects one hard drive as hotspare. Now: Is there ANY possibility to tell it to use two hot spares?
Best regards,
Joerg
Anonymous
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February 4th, 2014 06:00
Hello,
Sorry, no there's isn't.
joergriether
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February 4th, 2014 06:00
Thanks Don. Please take this as a suggestion for future release. I find it strange you can use the CLI to configure no hot spare at all but you can´t configure two.
Best regards,
Joerg
joergriether
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February 4th, 2014 07:00
Hi Don,
I mainly focus on performance! with a heavy loaded database system running on a raid6 lun eql, the performance suffers massive when the set is degraded and no spare part is available for a rebuild. so i guess i´d go with the on site spare.
Best regards,
Joerg
joergriether
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February 4th, 2014 07:00
With a running raid6 rebuild operation the possibility to lose another drive is not high but it is quite existent - you can´t deny that. So - there may be some users who want this little extra peace of mind. Thus - please accept this suggestion and please let the dev guys at least talk about it for a few mins. Can you please do that for me?
Best regards,
Joerg
Anonymous
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February 4th, 2014 07:00
With RAID6 you have double parity, so the need for dual spares is greatly depreciated. Going with a single spare gives you that extra drives capacity.
RAID50 has two spares since the risk is greater of a double fault. Since RAID50 is two RAID5 sets put together.
Regards,
Anonymous
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February 4th, 2014 07:00
Hello Joerg,
With R6, dual parity it would take three drives failing at the same time to bring down the RAIDset. That I think you would agree is much less likely. Once the failed drive is replaced, even without a spare anymore you can still survive two more failures.
Running current firmware on the array and if applicable firmware on the drives will also reduce the risk. As failing drives will be mirrored out first, precluding the need for a rebuild. Also reducing the chance of a double faulted RAIDset.
Having a cold spare onsite would provide you with that extra level of protection.
Regards,