[Novalug] LVM vs Partitions
James Ewing Cottrell 3rd
JECottrell3@Comcast.NET
Tue Mar 16 02:03:03 EDT 2010
Bryan J. Smith wrote:
>
> I mean, people remove hardware and then wonder why LVM is warning
> them.
But gee, all I removed was a *virtual* disk, not a *real* disk :)
I will admit to being a slow adopter of LVM, but just to clear up some
of my prior rants, they weren't about LVM. LVM is pretty cool, and has
pretty good documentation written on it.
I also share Bryan Smith's disdain of RAID-5. Every write requires N-2
reads to fetch the appropriate data to compute the XOR Parity, and 2
writes, so every disk is hit.
It probably gets even worse with atime, as those superblock (and copies
of them) updates probably get written to all the disks as well.
Dedicated RAID boxen, and stuff like NetApp probably have their own
special hardware to aid in the XOR'ing.
JIM
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