Comment 9 for bug 474207

When the server was first built as Lucid sdb not only faulted when it was re-syncing, a replacement sdb also faulted during re-syncing. The second replacement drive worked fine once the server was rebuilt as Hardy; I haven't retried the first one.

looking at the patch in
http://kerneltrap.org/mailarchive/linux-scsi/2010/4/26/6884716
it appears you are actually supposed to use blk_queue_update_dma_alignment()
but the difference it makes is trivial in reality.

diff -u mptscsih.c.DIST mptscsih.c
--- mptscsih.c.DIST 2010-05-12 10:35:04.326544905 -0400
+++ mptscsih.c 2010-05-12 16:23:40.948596315 -0400
@@ -2363,6 +2363,9 @@
                ioc->name,sdev->tagged_supported, sdev->simple_tags,
                sdev->ordered_tags));

+ blk_queue_update_dma_alignment(sdev->request_queue, 512 - 1);
+ printk(KERN_INFO, "sdev->request_queue->dma_alignment set to %d", sdev->request_queue->dma_alignment);
+
        return 0;
 }

but no joy. The printk message shows up twice in the dmesg output but

May 12 16:57:54 eeekamouse kernel: [ 662.544667] sd 6:0:1:0: [sdb] Sense Key : Recovered Error [current] [descriptor]
May 12 16:57:54 eeekamouse kernel: [ 662.544681] Descriptor sense data with sense descriptors (in hex):
May 12 16:57:54 eeekamouse kernel: [ 662.544687] 72 01 00 1d 00 00 00 0e 09 0c 00 00 00 00 00 00
May 12 16:57:54 eeekamouse kernel: [ 662.544705] 00 00 00 00 00 00
May 12 16:57:54 eeekamouse kernel: [ 662.544715] sd 6:0:1:0: [sdb] Add. Sense: ATA pass through information available
May 12 16:57:54 eeekamouse kernel: [ 662.570602] sd 6:0:1:0: [sdb] Sense Key : Recovered Error [current] [descriptor]
May 12 16:57:54 eeekamouse kernel: [ 662.570616] Descriptor sense data with sense descriptors (in hex):
May 12 16:57:54 eeekamouse kernel: [ 662.570621] 72 01 00 1d 00 00 00 0e 09 0c 00 00 00 00 00 00
May 12 16:57:54 eeekamouse kernel: [ 662.570640] 00 00 00 00 00 00
May 12 16:57:54 eeekamouse kernel: [ 662.570649] sd 6:0:1:0: [sdb] Add. Sense: ATA pass through information available