NFS may run wild on a RHEL-5, the Typic error code is:
Code:
Dec 22 03:42:40 Host kernel: CR2: 00002aabb0fc2ed7 CR3: 00000007d3893000 CR4: 00000000000006e0
Dec 22 03:42:40 Host kernel:  
Dec 22 03:42:40 Host kernel: Call Trace:
Dec 22 03:42:40 Host kernel:  [<ffffffff88563302>] :nfs:nfs_access_cache_shrinker+0x2d/0x1da
Dec 22 03:42:40 Host kernel:  [<ffffffff8003edc2>] shrink_slab+0x60/0x153
Dec 22 03:42:40 Host kernel:  [<ffffffff800c8216>] try_to_free_pages+0x1c8/0x2c2
Dec 22 03:42:40 Host kernel:  [<ffffffff8000f270>] __alloc_pages+0x1cb/0x2ce
Dec 22 03:42:40 Host kernel:  [<ffffffff80012a77>] __do_page_cache_readahead+0xa2/0x1e6
Dec 22 03:42:40 Host kernel:  [<ffffffff8006dd28>] do_gettimeofday+0x40/0x8f
Dec 22 03:42:40 Host kernel:  [<ffffffff8005a2d3>] getnstimeofday+0x10/0x28
Dec 22 03:42:40 Host kernel:  [<ffffffff8009fb73>] ktime_get_ts+0x1a/0x4e
Dec 22 03:42:40 Host kernel:  [<ffffffff800bab03>] delayacct_end+0x5d/0x86
Dec 22 03:42:40 Host kernel:  [<ffffffff80031e9b>] blockable_page_cache_readahead+0x53/0xb2
Dec 22 03:42:40 Host kernel:  [<ffffffff8002eb23>] make_ahead_window+0x82/0x9e
Dec 22 03:42:40 Host kernel:  [<ffffffff800076eb>] find_get_page+0x4c/0x50
Dec 22 03:42:40 Host kernel:  [<ffffffff80013c10>] page_cache_readahead+0x17f/0x1af
Dec 22 03:42:40 Host kernel:  [<ffffffff8000beee>] do_generic_mapping_read+0xce/0x3ab
Dec 22 03:42:40 Host kernel:  [<ffffffff8000cdf5>] file_read_actor+0x0/0x154
It's a kernel bug, will be fixed in RHEL-5u8.
Please refer to https://bugzilla.redhat.com/show_bug.cgi?id=585935 for more details.