JPerkSter's questions

We currently use smartd to monitor SMART health on our disks. I would like to set the 'thresholds' that smartd uses to report.

For example:

197 Current_Pending_Sector  0x0012   100   100   000    Old_age   Always       -       9
198 Offline_Uncorrectable   0x0010   100   100   000    Old_age   Offline      -       9

I would like to be able to set a threshold for these two attributes to only report if they are above 10. I haven't been able to find a way to set this via smartd.conf, and I'm also not looking to actually shutdown the daemon.

Has anyone ever tried this, or know how I might be able to accomplish this better then throwing a script into cron.hourly?

Good morning,

I'm seeing an issue on a few servers that they are going 'dirty' a lot, around once a month.

For example: This was on 11/8:

# tune2fs -l /dev/sda7 | grep state
Filesystem state:         clean with errors

We ran a fsck on home, and it cleaned up fine:

12552126 inodes used (11.38%)
  628394 non-contiguous inodes (1.6%)
         # of inodes with ind/dind/tind blocks: 589193/11935/1
109892528 blocks used (49.83%)
       0 bad blocks
       4 large files

11673859 regular files
  867367 directories
       0 character device files
       0 block device files
       0 fifos
    1242 links
   10891 symbolic links (10883 fast symbolic links)
       0 sockets
--------
12553359 files

However, now it's dirty again!:

# tune2fs -l /dev/sda7 | grep state
Filesystem state:         clean with errors

# grep EXT3 /var/log/messages
Dec 16 20:22:44 server kernel: EXT3-fs error (device sda7): ext3_lookup: deleted inode referenced: 105628446
Dec 16 20:22:44 server kernel: EXT3-fs error (device sda7): ext3_lookup: deleted inode referenced: 105628446

I'm honestly not sure where to go from here. Any suggestions / pointers are greatly appreciated.

Happy holidays!

I need some assistance with some sed replaces:

sed -ri 's#logging {
/*      If you want to enable debugging, eg. using the 'rndc trace' command,
 *      named will try to write the 'named.run' file in the $directory (/var/named").
 *      By default, SELinux policy does not allow named to modify the /var/named" directory,
 *      so put the default debug log file in data/ :
 */
    channel default_debug {
            file "data/named.run";
            severity dynamic;
    };
};
#logging {
/*      If you want to enable debugging, eg. using the 'rndc trace' command,
 *      named will try to write the 'named.run' file in the $directory (/var/named").
 *      By default, SELinux policy does not allow named to modify the /var/named" directory,
 *      so put the default debug log file in data/ :
 */
    channel default_debug {
            file "data/named.run";
            severity dynamic;
    };
category security { null; };
};
#g' /etc/named.conf

Basically I'm trying to add "category security { null; };" to /etc/named.conf (different line numbers on different servers) on quite a few systems, and sed is failing out on me.

Any tips and suggestions would be greatly appreciated.

Is it possible to 'colorize' the output from find?

I have a find that searches /home on all of my servers, and exec 'rm' certain files. As these are mixed in with my other find results, among other things, I'd like to colorize them.

Is this possible?

I had no idea how to word the title.

I need to take an output such as:

[~]# cat file
user1
domain1.com
user2
domain2.com
user3
domain3.com

and turn it into an output such as:

user1 domain1.com
user2 domain2.com
user3 domain3.com

Any assistance here would be greatly appreciated.

Are there any downsides to raising the size of the read-ahead cache?

On our farm, we're currently running at 256, and upon raising that higher, we are seeing significant throughput gains.

[root@server~]# hdparm -tT /dev/sda /dev/sda: 
Timing cached reads: 7352 MB in 2.00 seconds = 3677.62 MB/sec 3
Timing buffered disk reads: 244 MB in 3.10 seconds = 78.68 MB/sec 

[root@server ~]# blockdev --setra 10240 /dev/sda 

[root@server ~]# hdparm -tT /dev/sda /dev/sda: 
Timing cached reads: 11452 MB in 2.00 seconds = 5728.52 MB/sec 
Timing buffered disk reads: 422 MB in 3.17 seconds = 133.04 MB/sec

We are running on 2.6.

I've been seeing a few issues lately on a few of my servers where an account gets hacked via outdated scripts, and the hacker uploads a cPanel / FTP Brute forcing PHP script inside the account.

The PHP File reads /etc/passwd to get the usernames, and than uses a passwd.txt file to try and brute force it's way in to 127.0.0.1:2082.

I'm trying to think of a way to block this. It doesn't POST anything except "GET /path/phpfile.php", so I can't use mod_security to block this.

I've been thinking of maybe changing permissions on /etc/passwd to 600, however I'm unsure how this will result in regards to my users.

I was also thinking of rate-limiting localhost connections to :2082, however I'm worried about mod_proxy being affected.

Any suggestions?

We use LiveCD's alot in my line of work. Whether it be fscking file systems, recovering data from a customer to rm'd his server, etc.

I'm looking for a quick way to eject the CDROM and reboot the server.

Does anyone have any one-liners to do this or any other suggestions? Using 'eject' doesn't work most of the time, from what I've tested / used.

We're using RHEL / Cent on most of our servers if that helps :D