LVM2 vs MDADM performance

Posted by archer on Server Fault See other posts from Server Fault or by archer
Published on 2010-04-19T07:10:29Z Indexed on 2010/04/19 7:14 UTC
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Filed under:

lvm

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lvm2

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mdadm

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linux

I've used MDADM + LVM2 on many boxes for quite a while. MDADM was serving for both RAID0 and RAID1 arrays, while LVM2 where used for logical volumes on top of MDADM.

Recently I've found that LVM2 could be used w/o MDADM (thus minus one layer, as the result - less overhead) for both mirroring and stripping.

However, some guys claims that READ PERFORMANCE on LVM2 for mirrored array is not that fast as for LVM2 (linear) on top of MDADM (RAID1) as LVM2 does not read from 2+ devices at a time, but use 2nd and higher devices in case of 1st device failure. MDADM reads from 2 devices at a time (even in mirrored mode).

Who could confirm that?

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