Message-ID: <email address hidden>
Date: Tue, 27 Dec 2005 14:07:42 +0100
From: Sven Joachim <email address hidden>
To: <email address hidden>
CC: <email address hidden>, <email address hidden>
Subject: Problem is gone in version 0.97-2
In the new grub package 0.97-2, I no longer see the dreadful message
Error 21: Selected disk does not exist
when running grub unter a 2.4 kernel. AFICT, the only change that can be
responsible for this welcome change is the removal of the odirect.diff
patch, which was supposed to close #341888. And in the manpage for open(2)
I found the following statement about a difference between 2.4 and 2.6
kernelswhich supports this conjecture:
O_DIRECT
Try to minimize cache effects of the I/O to and from this file.
In general this will degrade performance, but it is useful in
special situations, such as when applications do their own
caching. File I/O is done directly to/from user space buffers.
The I/O is synchronous, i.e., at the completion of a read(2) or
write(2), data is guaranteed to have been transferred. Under
Linux 2.4 transfer sizes, and the alignment of user buffer and
file offset must all be multiples of the logical block size of
the file system. Under Linux 2.6 alignment to 512-byte boundaries
suffices.
So it seems that the odirect.diff patch introduced the problem, and since
it has been removed I'm closing this bug.
Message-ID: <email address hidden>
Date: Tue, 27 Dec 2005 14:07:42 +0100
From: Sven Joachim <email address hidden>
To: <email address hidden>
CC: <email address hidden>, <email address hidden>
Subject: Problem is gone in version 0.97-2
In the new grub package 0.97-2, I no longer see the dreadful message
Error 21: Selected disk does not exist
when running grub unter a 2.4 kernel. AFICT, the only change that can be
responsible for this welcome change is the removal of the odirect.diff
patch, which was supposed to close #341888. And in the manpage for open(2)
I found the following statement about a difference between 2.4 and 2.6
kernelswhich supports this conjecture:
O_DIRECT
Try to minimize cache effects of the I/O to and from this file.
In general this will degrade performance, but it is useful in
special situations, such as when applications do their own
caching. File I/O is done directly to/from user space buffers.
The I/O is synchronous, i.e., at the completion of a read(2) or
write(2), data is guaranteed to have been transferred. Under
Linux 2.4 transfer sizes, and the alignment of user buffer and
file offset must all be multiples of the logical block size of
the file system. Under Linux 2.6 alignment to 512-byte boundaries
suffices.
So it seems that the odirect.diff patch introduced the problem, and since
it has been removed I'm closing this bug.