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I have some Kernel errors that I've seen over the last couple of weeks that I think point to needing to run fsck - those would be the first four lines of this log. The rest of the log just appeared today for the first time. I have two questions.
1. Is my assessment of the first 4 lines correct?
2. It appears the rest of the log (to the best of my ability so far) to be related to a memory leak in kde4 and it was killed automatically. Is that what you guys see, and if so how do I fix it?
Any help would be very much appreciated, & thank you in advance. I am fairly new to troubleshooting these things.
---------------------- Kernel Begin -------------------------
WARNING: Kernel Errors Present
EXT4-fs (sda6): error count: 52 ...: 1 Time(s)
EXT4-fs (sda6): initial error at 1411646848: e ...: 1 Time(s)
EXT4-fs (sda6): last error at 1413904236: e ...: 1 Time(s)
I see a system running low on memory.
I am very concerned by the presence of 27 instances of sshd running on your system. I fear that you have poor security on your secure shell configuration which is allowing hackers to exploit your system.
Ok, memory I can deal with. I saw those ssh sessions. I have been a little concerned about security so over the last week I actually ended up trying to harden our systems. Removing any unnecessary logins and the couple that I still allow creating much harder passwords from a password generator with upper/lower case letters, not dictionary words and special characters. I figured this out when I started looking 1 - we did not have zones setup on our two network interfaces and more importantly 2 - the firewall was down for some amount of time. Both of those issues have been fixed. Couldn't the low memory be caused by the memory leak in kde4? We were having an issue with periodic high cpu utilization and it seemed to be caused by NVidia video problem. I lowered the resolution and we have not had that problem in over two weeks. So how, then would you approach this to clean it up best? And thank you for your help.
Last edited by Qujo33; 11-04-2014 at 09:14 AM.
Reason: add information
This server does multiple backups using rsync and ssh. I am not sure of the timing as to when the problem happened that generated this dump file - but we could have had multiple rsync ssh sessions going at that time. I am looking into it - wouldn't this explain some of it? Again, I am looking but additional thoughts are welcome.
This was our very first Linux server - coming from a Novell Netware world. The consultant who helped us felt it would be an easier adjustment (it was) and he noted that it would be less resource intensive to run it without the GUI. I think at this point I could go without it but others in my organization likely couldn't in my absence.
Using a GUI is fun, helpful but not actually efficient, the best is the command line, it's my day-to-day job, putty is my best collegue.
When you 've a crash, do you 've entries in /var/log/Xorg.log ? I guess, a shared memory matter with the video.
Xorg.log lists this:
Buggy monitor, no preferred refresh rate given
Not using mode "1280x1024" (bad mode clock/interlace/doublescan)
I think I am getting closer to the main issue. Using dmesg I get the following few lines:
[ 24.170624] EXT4-fs (sda6): warning: mounting fs with errors, running e2fsck is recommended
[ 33.009871] EXT4-fs error (device sda6): ext4_mb_generate_buddy:755: group 1, 23068 clusters in bitmap, 23067 in gd
[ 50.181536] EXT4-fs error (device sda6): ext4_mb_generate_buddy:755: group 73, 32605 clusters in bitmap, 32604 in gd
[ 50.182082] JBD2: Spotted dirty metadata buffer (dev = sda6, blocknr = 0). There's a risk of filesystem corruption in case of system crash.
[ 56.858276] EXT4-fs error (device sda6): ext4_mb_generate_buddy:755: group 143, 32744 clusters in bitmap, 32721 in gd
[ 321.474172] EXT4-fs (sda6): error count: 64
[ 321.474189] EXT4-fs (sda6): initial error at 1411646848: ext4_lookup:1438: inode 1179805
[ 321.474196] EXT4-fs (sda6): last error at 1415213558: ext4_mb_generate_buddy:755
The last error works out to when I rebooted it at lunch to try to run fsck on the sda6 partition - which is my root partition.
In booting from the rescue option from the OpenSUse 13.1 (same version) USB. I try fsck /dev/sda6 and it says "Possibly non-existent device?". However I can run fsck on /dev/sda. Now this is a two drive Dell system that has hardware RAID and two 1TB disks in it. When attempting to do this I get the error:
fsck.ext4: Bad magic number in super-block while trying to open /dev/sda
The superblock could not be read or does not describe a correct ext2
filesystem. If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193 <device>
I did not know the block size at that time so I ended up having to boot the machine and find it out (4096). And at that time it was time to let the users back on it. I know this is NOT a good idea but I do have bosses.... So I am guessing my next attempt would be to boot it back to rescue and try the following command:
e2fsck -b 32768 /dev/sda
Is that correct?
Since Linux only sees the two drives as one drive I am guessing that really doesn't do me any good and the problem is likely on both drives.