Re: thin provisioned LUN support & file system allocation policy

Theodore Tso
2008-11-07T15:47:00Z

On Fri, Nov 07, 2008 at 10:35:13AM -0500, jim owens wrote:
>
> I'm talking DISK wear not SSD. The array vendors who are causing
> this problem are doing petabyte san devices, not SSDs.
>
> Rewriting the same sectors causes more bad block remaps
> until the drive eventually runs out of remap space.

How much of a disk wear factor is there with modern disk drives? The
heads aren't touching the disk, and we have plenty of sectors which
are constantly getting rewritten with traditional filesystems, with no
ill effects as far as I know. For example, FAT filesystems, the
superblock, block allocation bitmaps all are constantly getting
rewritten today, and I haven't heard of disk manufacturers complaining
that this is a horrible thing.

- Ted