在我的网站 VPS 上，MySQL 经常出现故障，最近一天一次。
我查看了我的系统日志，似乎是内存不足错误。
是我的 MySQL 没有以正确的方式配置，还是我的 VPS 没有足够的内存来运行它？
这里是免费的和顶级的：
$ free -m
total used free shared buffers cached
Mem: 512 360 151 0 0 42
-/+ buffers/cache: 317 194
Swap: 0 0 0
top - 14:17:47 up 15 days, 9:41, 2 users, load average: 0.13, 0.30, 0.42
Tasks: 58 total, 1 running, 57 sleeping, 0 stopped, 0 zombie
Cpu(s): 19.7%us, 2.7%sy, 0.0%ni, 77.6%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 524508k total, 415200k used, 109308k free, 0k buffers
Swap: 0k total, 0k used, 0k free, 72404k cached
在 my.cnf 中：
# * Fine Tuning
#
key_buffer = 16M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 8
我正在
mysql Ver 14.14 Distrib 5.1.66, for debian-linux-gnu (x86_64) using readline 6.1
使用
Debian GNU/Linux 6.0.7 (squeeze)
这是我的系统日志中的块：
Jun 23 21:19:01 vps528 kernel: [1182395.730776] mysqld invoked oom-killer: gfp_mask=0x1201d2, order=0, oomkilladj=0
Jun 23 21:19:01 vps528 kernel: [1182395.730789] Pid: 13220, comm: mysqld Not tainted 2.6.24-19-xen #1
Jun 23 21:19:01 vps528 kernel: [1182395.730791]
Jun 23 21:19:01 vps528 kernel: [1182395.730792] Call Trace:
Jun 23 21:19:01 vps528 kernel: [1182395.730802] [<ffffffff80275e26>] oom_kill_process+0xf6/0x110
Jun 23 21:19:01 vps528 kernel: [1182395.730806] [<ffffffff802762ae>] out_of_memory+0x19e/0x1e0
Jun 23 21:19:01 vps528 kernel: [1182395.730810] [<ffffffff80278bd9>] __alloc_pages+0x389/0x3c0
Jun 23 21:19:01 vps528 kernel: [1182395.730815] [<ffffffff8027af54>] __do_page_cache_readahead+0x104/0x260
Jun 23 21:19:01 vps528 kernel: [1182395.730818] [<ffffffff8027520e>] filemap_fault+0x2de/0x3e0
Jun 23 21:19:01 vps528 kernel: [1182395.730822] [<ffffffff80281f3a>] __do_fault+0x6a/0x5d0
Jun 23 21:19:01 vps528 kernel: [1182395.730824] [<ffffffff80287551>] handle_mm_fault+0x1d1/0xd60
Jun 23 21:19:01 vps528 kernel: [1182395.730829] [<ffffffff80229f63>] set_next_entity+0x23/0x50
Jun 23 21:19:01 vps528 kernel: [1182395.730835] [<ffffffff80473553>] do_page_fault+0x1f3/0x11e0
Jun 23 21:19:01 vps528 kernel: [1182395.730840] [<ffffffff8046f7e9>] thread_return+0x3a/0x481
Jun 23 21:19:01 vps528 kernel: [1182395.730845] [<ffffffff80471bf7>] error_exit+0x0/0x79
Jun 23 21:19:01 vps528 kernel: [1182395.730848]
Jun 23 21:19:01 vps528 kernel: [1182395.730850] Mem-info:
Jun 23 21:19:01 vps528 kernel: [1182395.730851] DMA per-cpu:
Jun 23 21:19:01 vps528 kernel: [1182395.730853] CPU 0: Hot: hi: 0, btch: 1 usd: 0 Cold: hi: 0, btch: 1 usd: 0
Jun 23 21:19:01 vps528 kernel: [1182395.730855] DMA32 per-cpu:
Jun 23 21:19:01 vps528 kernel: [1182395.730857] CPU 0: Hot: hi: 186, btch: 31 usd: 172 Cold: hi: 62, btch: 15 usd: 14
Jun 23 21:19:01 vps528 kernel: [1182395.730861] Active:94084 inactive:618 dirty:0 writeback:0 unstable:0
Jun 23 21:19:01 vps528 kernel: [1182395.730861] free:4898 slab:3594 mapped:0 pagetables:3925 bounce:0
Jun 23 21:19:01 vps528 kernel: [1182395.730866] DMA free:11540kB min:28kB low:32kB high:40kB active:0kB inactive:0kB present:16160kB pages_scanned:0 all_unreclaimable? yes
Jun 23 21:19:01 vps528 kernel: [1182395.730869] lowmem_reserve[]: 0 4024 4024 4024
Jun 23 21:19:01 vps528 kernel: [1182395.730875] DMA32 free:8052kB min:8100kB low:10124kB high:12148kB active:376336kB inactive:2472kB present:4120800kB pages_scanned:767723 all_unreclaimable? yes
Jun 23 21:19:01 vps528 kernel: [1182395.730878] lowmem_reserve[]: 0 0 0 0
Jun 23 21:19:01 vps528 kernel: [1182395.730881] DMA: 3*4kB 3*8kB 3*16kB 4*32kB 3*64kB 1*128kB 1*256kB 1*512kB 2*1024kB 0*2048kB 2*4096kB = 11540kB
Jun 23 21:19:01 vps528 kernel: [1182395.730900] DMA32: 62*4kB 4*8kB 3*16kB 4*32kB 2*64kB 0*128kB 1*256kB 0*512kB 1*1024kB 1*2048kB 1*4096kB = 8008kB
Jun 23 21:19:01 vps528 kernel: [1182395.730908] Swap cache: add 0, delete 0, find 0/0, race 0+0
Jun 23 21:19:01 vps528 kernel: [1182395.730910] Free swap = 0kB
Jun 23 21:19:01 vps528 kernel: [1182395.730911] Total swap = 0kB
Jun 23 21:19:01 vps528 kernel: [1182395.730912] Free swap: 0kB
Jun 23 21:19:01 vps528 kernel: [1182395.740886] 1048576 pages of RAM
Jun 23 21:19:01 vps528 kernel: [1182395.740893] 21255 reserved pages
Jun 23 21:19:01 vps528 kernel: [1182395.740894] 39897 pages shared
Jun 23 21:19:01 vps528 kernel: [1182395.740895] 0 pages swap cached
Jun 23 21:19:01 vps528 kernel: [1182395.740898] Out of memory: kill process 25246 (apache2) score 73450 or a child
Jun 23 21:19:01 vps528 kernel: [1182395.740913] Killed process 25246 (apache2)