[linux-lvm] LVM on SATA/PATA disks

[Bryn M. Reeves]

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Stuart D. Gathman wrote:
> If out of order writes are enabled, then your server should hold power
> to the disk drives for part of a second after disabling further writes
> in software.  LVM is a low risk because LVM changes are comparatively
> rare, and the modification window is small.  But, theoretically, if
> you lost power right at the instant you pressed return on lvcreate,
> lvextend, or lvremove, on a system with busy disk io, you could corrupt
> the LVM metadata.

LVM metadata I/O does not pass through device-mapper unless you are
stacking volume groups so I'm not sure how your comment regarding
barriers is relevant here. It's also only going to affect devices under
snapshot and multipath mappings.

How does this differ from updating an MSDOS or GPT partition table, for
example?

Kind regards,

Bryn.
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