#777702 os-prober seems to hang, but is actually reading entire partition when a partition is not mounted

Package:
os-prober
Source:
os-prober
Description:
utility to detect other OSes on a set of drives
Submitter:
Clinton Mead
Date:
2015-02-11 16:42:07 UTC
Severity:
important
#777702#5
Date:
2015-02-11 16:38:01 UTC
From:
To:
Dear Maintainer,

I've found that 'update-grub' in jessie which calls 'os-prober', reads what
seems to be the entire partition if it isn't mounted. I've tested this on both
ext3 partitions in LVM and a btrfs partition. I am unsure if this occurs on an
ordinary non-lvm partition.

This would likely break the upgrade for any user upgrading to jessie, as the
read speed I experienced was less than 30GB/h which is close to forever for any
reasonably sized partition.

As a result, grub is not updated and the new kernel with jessie can not be
loaded.

Please feel free to reply at clintonmead@gmail.com if you require any further
details.

Clinton