diff --git a/config/kernel-bdev-logical-size.m4 b/config/kernel-bdev-logical-size.m4
new file mode 100644
index 0000000000..1e199663b1
--- /dev/null
+++ b/config/kernel-bdev-logical-size.m4
@@ -0,0 +1,22 @@
+dnl #
+dnl # 2.6.30 API change
+dnl # bdev_hardsect_size() replaced with bdev_logical_block_size().  While
+dnl # it has been true for a while that there was no strict 1:1 mapping
+dnl # between physical sector size and logical block size this change makes
+dnl # it explicit.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_BDEV_LOGICAL_BLOCK_SIZE], [
+	AC_MSG_CHECKING([whether bdev_logical_block_size() is available])
+	ZFS_LINUX_TRY_COMPILE([
+		#include <linux/blkdev.h>
+	],[
+		struct block_device *bdev = NULL;
+		bdev_logical_block_size(bdev);
+	],[
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_BDEV_LOGICAL_BLOCK_SIZE, 1,
+		          [bdev_logical_block_size() is available])
+	],[
+		AC_MSG_RESULT(no)
+	])
+])
diff --git a/config/kernel.m4 b/config/kernel.m4
index 6124f0fddb..916a6be73d 100644
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -6,6 +6,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
 	ZFS_AC_SPL
 	ZFS_AC_KERNEL_OPEN_BDEV_EXCLUSIVE
 	ZFS_AC_KERNEL_INVALIDATE_BDEV_ARGS
+	ZFS_AC_KERNEL_BDEV_LOGICAL_BLOCK_SIZE
 	ZFS_AC_KERNEL_BIO_END_IO_T_ARGS
 	ZFS_AC_KERNEL_BIO_RW_SYNCIO
 	ZFS_AC_KERNEL_BIO_EMPTY_BARRIER
diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 33984e79b2..880d737114 100644
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -517,7 +517,7 @@ static void arc_evict_ghost(arc_state_t *state, uint64_t spa, int64_t bytes);
  * Hash table routines
  */
 
-#define	HT_LOCK_PAD	64
+#define	HT_LOCK_PAD	256
 
 struct ht_lock {
 	kmutex_t	ht_lock;
diff --git a/module/zfs/include/sys/vdev_disk.h b/module/zfs/include/sys/vdev_disk.h
index 06063d2c3d..544036bbc0 100644
--- a/module/zfs/include/sys/vdev_disk.h
+++ b/module/zfs/include/sys/vdev_disk.h
@@ -55,6 +55,13 @@ extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
 # define vdev_bdev_invalidate(bdev)	invalidate_bdev(bdev, 1)
 #endif /* HAVE_1ARG_INVALIDATE_BDEV */
 
+/* 2.6.30 API change */
+#ifdef HAVE_BDEV_LOGICAL_BLOCK_SIZE
+# define vdev_bdev_block_size(bdev)	bdev_logical_block_size(bdev)
+#else
+# define vdev_bdev_block_size(bdev)	bdev_hardsect_size(bdev)
+#endif
+
 #endif /* _KERNEL */
 
 #ifdef	__cplusplus
diff --git a/module/zfs/vdev_disk.c b/module/zfs/vdev_disk.c
index 656e62edf7..c1e0aa7794 100644
--- a/module/zfs/vdev_disk.c
+++ b/module/zfs/vdev_disk.c
@@ -94,7 +94,7 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *ashift)
 {
 	struct block_device *bdev;
 	vdev_disk_t *vd;
-	int mode;
+	int mode, block_size;
 
 	/* Must have a pathname and it must be absolute. */
 	if (v->vdev_path == NULL || v->vdev_path[0] != '/') {
@@ -129,6 +129,7 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *ashift)
 
 	v->vdev_tsd = vd;
 	vd->vd_bdev = bdev;
+	block_size =  vdev_bdev_block_size(bdev);
 
 	/* Check if this is a whole device.  When bdev->bd_contains ==
 	 * bdev we have a whole device and not simply a partition. */
@@ -138,10 +139,10 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *ashift)
 	v->vdev_nowritecache = B_FALSE;
 
 	/* Physical volume size in bytes */
-	*psize = bdev_capacity(bdev) * bdev_hardsect_size(bdev);
+	*psize = bdev_capacity(bdev) * block_size;
 
 	/* Based on the minimum sector size set the block size */
-	*ashift = highbit(MAX(bdev_hardsect_size(bdev), SPA_MINBLOCKSIZE)) - 1;
+	*ashift = highbit(MAX(block_size, SPA_MINBLOCKSIZE)) - 1;
 
 	return 0;
 }
@@ -310,7 +311,7 @@ __vdev_disk_physio(struct block_device *bdev, zio_t *zio, caddr_t kbuf_ptr,
 	caddr_t bio_ptr;
 	uint64_t bio_offset;
 	int bio_size, bio_count = 16;
-	int i = 0, error = 0;
+	int i = 0, error = 0, block_size;
 
 retry:
 	dr = vdev_disk_dio_alloc(bio_count);
@@ -319,6 +320,7 @@ retry:
 
 	dr->dr_zio = zio;
 	dr->dr_rw = flags;
+	block_size = vdev_bdev_block_size(bdev);
 
 #ifdef BIO_RW_FAILFAST
 	if (flags & (1 << BIO_RW_FAILFAST))
@@ -364,7 +366,7 @@ retry:
 		vdev_disk_dio_get(dr);
 
 		dr->dr_bio[i]->bi_bdev = bdev;
-		dr->dr_bio[i]->bi_sector = bio_offset/bdev_hardsect_size(bdev);
+		dr->dr_bio[i]->bi_sector = bio_offset / block_size;
 		dr->dr_bio[i]->bi_rw = dr->dr_rw;
 		dr->dr_bio[i]->bi_end_io = vdev_disk_physio_completion;
 		dr->dr_bio[i]->bi_private = dr;
@@ -573,7 +575,7 @@ vdev_disk_read_rootlabel(char *devpath, char *devid, nvlist_t **config)
 	if (IS_ERR(bdev))
 		return -PTR_ERR(bdev);
 
-	s = bdev_capacity(bdev) * bdev_hardsect_size(bdev);
+	s = bdev_capacity(bdev) * vdev_bdev_block_size(bdev);
 	if (s == 0) {
 		vdev_bdev_close(bdev, vdev_bdev_mode(FREAD));
 		return EIO;