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I'm running a virtualized CentOS machine, which has been running pretty well so far. Today, I noticed that some PHP extensions were missing, and realized that the problem was coming from unreadable config files. If I try to list the relevant directory, here is what happens:

[root@localhost php.d]# ls -al
ls: cannot access sysvmsg.ini: Input/output error
ls: cannot access sysvshm.ini: Input/output error
ls: cannot access memcache.ini: Input/output error
ls: cannot access bcmath.ini: Input/output error
ls: cannot access sysvsem.ini: Input/output error
ls: cannot access posix.ini: Input/output error
total 120
drwxr-xr-x    2 root root  4096 Nov  9 13:25 .
drwxr-xr-x. 112 root root 12288 Nov  9 13:17 ..
-rw-r--r--    1 root root  3070 Sep 16 14:44 apc.ini
-??????????   ? ?    ?        ?            ? bcmath.ini
-rw-r--r--    1 root root    49 Sep 25 09:54 curl.ini
-rw-r--r--    1 root root    47 Sep 25 09:54 dom.ini
-rw-r--r--    1 root root    57 Sep 25 09:54 fileinfo.ini
-rw-r--r--    1 root root    45 Sep 25 09:54 gd.ini

Any idea where that might be coming from?

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up vote 2 down vote accepted

probably bad sectors on the disk or the disk's data/power cable are loose. to verify disk health, install smartmontools, which will give you details of the disk health. also try to run e3fsck to check for errors on file-system.

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Good bet, the virtual disk was indeed located on a USB disk which had been improperly unplugged. chkdsk on the Windows host + fsck on the Linux guest, and everything is working fine. Thanks! – Benjamin Nov 9 '11 at 14:37
You are welcome. – Farhan Nov 9 '11 at 14:39

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