系统崩溃？求解。

[redvalley]

ubuntu11.04beta 64位(大概2011-04-25的，没来得及更新)，之前一切正常，今天中午突然所有文件都不能修改。
vsftpd不能启动，因为无/var/log/vsftpd.log权限(其实所有文件都不能写！)。

使用root用户，chmod chown都不管用。

如：
root@js:/# ls -l /var/log/vsftpd.log
-rw-r----- 1 root adm 13725 2011-05-11 01:59 /var/log/vsftpd.log

root@js:/# chmod +rw /var/log/vsftpd.log
chmod: 更改"/var/log/vsftpd.log" 的权限: 只读文件系统

#不能重启
root@js:/# shutdown -r
-bash: /sbin/shutdown: 输入/输出错误

#不能更新
root@js:/# apt-get dist-upgrade
总线错误

#不能初始化
root@js:/# init 0
段错误

#等等...
root@js:/# fdisk -l
-bash: /sbin/fdisk: 输入/输出错误


磁盘
sda固态硬盘64G，系统安装时自动分区.
sdb、sdc... 后面挂载上去的，使用正常。

系统在sda上所有目录、文件都不能更改，很多命令无效，这算系统崩溃吗？
但apache还正常跑着(sda1)，日志截至到中午，后面便没了(应该是没权限写入了)。

查看日志，无入侵痕迹。

----[kern.log]----
May 10 10:54:39 js kernel: [1186734.020053] ata4: device not ready (errno=-16), forcing hardreset
May 10 10:54:39 js kernel: [1186734.020063] ata4: soft resetting link
May 10 10:54:40 js kernel: [1186734.772416] ata4.00: configured for UDMA/133
May 10 10:54:40 js kernel: [1186735.059280] ata4.01: configured for UDMA/133
May 10 10:54:40 js kernel: [1186735.059288] ata4.01: device reported invalid CHS sector 0
May 10 10:54:40 js kernel: [1186735.059301] ata4: EH complete
May 10 11:46:55 js kernel: [1189870.040072] ata4.01: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
May 10 11:46:55 js kernel: [1189870.040081] ata4.01: failed command: WRITE DMA EXT
May 10 11:46:55 js kernel: [1189870.040089] ata4.01: cmd 35/00:08:5f:41:04/00:00:18:00:00/f0 tag 0 dma 4096 out
May 10 11:46:55 js kernel: [1189870.040091] res 40/00:00:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout)
May 10 11:46:55 js kernel: [1189870.040095] ata4.01: status: { DRDY }
May 10 11:47:00 js kernel: [1189875.080042] ata4: link is slow to respond, please be patient (ready=0)
May 10 11:47:05 js kernel: [1189880.060040] ata4: device not ready (errno=-16), forcing hardreset
May 10 11:47:05 js kernel: [1189880.060051] ata4: soft resetting link
May 10 11:47:09 js kernel: [1189884.729068] ata4.00: configured for UDMA/133
May 10 11:47:10 js kernel: [1189884.860170] ata4.01: configured for UDMA/133
May 10 11:47:10 js kernel: [1189884.860179] ata4.01: device reported invalid CHS sector 0
May 10 11:47:10 js kernel: [1189884.860194] ata4: EH complete
May 11 11:24:26 js kernel: [1274920.960071] ata3.01: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
May 11 11:24:26 js kernel: [1274920.960081] ata3.01: failed command: IDENTIFY DEVICE
May 11 11:24:26 js kernel: [1274920.960089] ata3.01: cmd ec/00:01:00:00:00/00:00:00:00:00/10 tag 0 pio 512 in
May 11 11:24:26 js kernel: [1274920.960091] res 40/00:00:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout)
May 11 11:24:26 js kernel: [1274920.960095] ata3.01: status: { DRDY }
May 11 11:24:28 js kernel: [1274923.000046] ata3: soft resetting link
May 11 11:24:32 js kernel: [1274926.930244] ata3.00: configured for UDMA/100
May 11 11:24:37 js kernel: [1274931.930051] ata3.01: qc timeout (cmd 0xef)
May 11 11:24:37 js kernel: [1274931.930057] ata3.01: failed to set xfermode (err_mask=0x4)
May 11 11:24:41 js kernel: [1274935.830045] ata3: soft resetting link
May 11 11:24:41 js kernel: [1274936.072516] ata3.00: configured for UDMA/100
May 11 11:24:41 js kernel: [1274936.147978] ata3.01: configured for UDMA/133
May 11 11:24:41 js kernel: [1274936.148003] ata3: EH complete
May 11 11:54:26 js kernel: [1276721.000067] ata3.01: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
May 11 11:54:26 js kernel: [1276721.000077] ata3.01: failed command: IDENTIFY DEVICE
May 11 11:54:26 js kernel: [1276721.000085] ata3.01: cmd ec/00:01:00:00:00/00:00:00:00:00/10 tag 0 pio 512 in
May 11 11:54:26 js kernel: [1276721.000087] res 40/00:00:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout)
May 11 11:54:26 js kernel: [1276721.000091] ata3.01: status: { DRDY }
May 11 11:54:31 js kernel: [1276726.040037] ata3: link is slow to respond, please be patient (ready=0)

[redvalley]

kern.log信息看不懂，难道sda要挂了？
刚买的金士顿固态硬盘，貌似xrdp一直在跑(连接不稳定，忘记关了，今天才kill)，就这样跑坏了也太差了吧？狂郁闷，机器在机房托管。

df结果
-----------------------------------------
文件系统 1K-块 已用 可用 已用% 挂载点
/dev/sda1 55353412 8065288 44476324 16% /
none 3052020 624 3051396 1% /dev
none 3059732 104 3059628 1% /dev/shm
none 3059732 400 3059332 1% /var/run
none 3059732 0 3059732 0% /var/lock
/dev/sdd1 307663800 232132 291803236 1% /sdd
/dev/sdc1 307663800 338596 291696772 1% /sdc
/dev/sdb1 307663800 195416 291839952 1% /sdb