Questions tagged [linux]
Linux is the generic term for a UNIX-like open source operating system based on the Linux kernel.
38,564
questions
-1
votes
1
answer
80
views
Need to transfer the free volume group space to another volume group space
I need to transfer the free volume group space to another volume group space ..
Is it possible ?
VG #PV #LV #SN Attr VSize VFree
vg0_kwt_r3oql20 2 3 0 wz--n- 175.66g ...
- 11
2
votes
0
answers
73
views
PHP APC cannot increase cache above 32m
apc.shm_size I set it to 128M I have also try 128 (without M)
But It always 32M :(
/proc/sys/kernal/shmmax is set to 134217728
- 21
93
votes
16
answers
72k
views
Why drop caches in Linux?
In our servers we have a habit of dropping caches at midnight.
sync; echo 3 > /proc/sys/vm/drop_caches
When I run the code it seems to free up lots of RAM, but do I really need to do that. Isn't ...
- 1,072
0
votes
3
answers
784
views
Optimize Apache [closed]
I am trying to optimize apache on my virtual server on Digital Cloud hosting. I am following a tutorial that tells me to make sure the following values are set in my apache2.conf
KeepAlive Off
...
&...
- 117
1
vote
2
answers
2k
views
Can I find the list of ports being listened by a process ordered by the time of opening?
I know I can see the list of open ports using the lsof command.
I am trying to view the results ordered by timestamp of listening.
The process opens multiple (~6) ports and I suspect the order of ...
- 113
0
votes
2
answers
4k
views
What does "STA" mean in "Broadcom STA driver"? [closed]
I've been wondering for some time now, what does STA stand for?
Context: Broadcom 802.11 Linux STA wireless driver
Example: http://www.broadcom.com/support/802.11/linux_sta.php
- 111
15
votes
1
answer
3k
views
Why did rebooting cause one side of my ZFS mirror to become UNAVAIL?
I just recently migrated a bulk data storage pool (ZFS On Linux 0.6.2, Debian Wheezy) from a single-device vdev configuration to a two-way mirror vdev configuration.
The previous pool configuration ...
- 4,455
1
vote
1
answer
1k
views
Set up multiple VPN's with a static ip with PPTP with only 1 vpn-login
I have a VPS with Ubuntu 12.04 x64 and i need to connect 118 VPN's to interfaces with (pon vpnname). I've made a script that creates them all, the problem is that no interface will have a unique local ...
1
vote
1
answer
11k
views
CentOS PAM unable to open /etc/pam.d/system-auth
In gdm I have checked "Require smartcard login" but forgot about adding any smartcard for authentication. Then I've tried to boot from LiveCD and disable SC auth. Something went wrong and now I am not ...
- 31
2
votes
1
answer
1k
views
Linux IP forwarding trouble
In my environment most of the servers have 2 network cards. A
primary/user network card used by the application, and a secondary/backup
adapter used for backups, bulk copies etc.
I just set up a ...
- 107
1
vote
2
answers
6k
views
Static NFS mounts vs autofs direct map mounts
We are in the process of re-designing our NFS service and are at a point where we can choose either to mount our NFS shares statically from /etc/fstab at boot or as autofs direct maps.
In our new ...
- 361
0
votes
1
answer
2k
views
Unable to access samba server
I can't connect to my samba server running CentOS 6.4 (minimal installation) that is not located within my network.
When I try to connect with my Windows 7 client, the connection fails and I get the ...
- 103
-2
votes
1
answer
463
views
Streaming Server Network Performance [duplicate]
I have server Linux based on
centos 6.5 final 64bit ,
ram 128 G.B
dual E5-2650 processor
Hard disk : 4 SSD Hard disk RAID-5
Network Speed 1/Gbps
Bandwidth Speed 500/Mbps up to 3/Gbps
My Wbebserv ...
- 17
4
votes
1
answer
4k
views
Linux page cache slows down IO on dual cpu server with 64GB ram
I have a massive problem with the linux page cache which slows down the IO. For instance if I copy a lvm partition with dd, linux cache the data in the buffers or caches (free –m). That is not the ...
- 73
9
votes
1
answer
5k
views
What does "Server ****** is not blacklisted" means in curl verbose output? [closed]
Why should the server be blacklisted ?
By curl or another program ?
How server can get blacklisted ?
Is it server or program dependant ?
Is this the IP address that get blacklisted, or the name ...
- 209
15
votes
6
answers
22k
views
How to find out the virtualization type of an linux VPS?
Having access to an VPS, i need to know which type of virtualization it is running from the terminal.
How can determine the virtualization platform that my VM is running on? (OpenVZ, Xen, KVM, etc?)
- 409
0
votes
1
answer
2k
views
unison as non-root user
I want to use unison to sync the /home directories between two EL6 boxes.
Most writeups assume that unison is run as root, and can ssh between the two boxes as root. However, we have disabled root ...
- 829
1
vote
2
answers
379
views
Access RPM database
I would like to find where information is stored about which RPM packages are installed?
I know that there is a internal database for this. Can I access somehow this database with Java?
- 55
0
votes
1
answer
100
views
Why can root see a dir but not a user?
I created a git repo on my vps through root and made it shared so a group of people have the ability to access it:
# mkdir example.git
# cd example.git
# git init --bare --shared=group
Initialized ...
- 109
0
votes
1
answer
160
views
Tomcat memory allocation removed by automatic updates
I'm hosting quite a few servers, for customers and for our own usage. All these servers run Debian Stable. All of the servers are virtual servers. This is for the eventuality that an automatic update ...
- 359
1
vote
0
answers
356
views
RabbitMQ server randomly, mysteriously stopping
I installed RabbitMQ on my EC2 box following the RPM install instructions from their website. My OS is CentOS. Every now and then, the rabbitMQ server just stops running, nothing shows up in the ...
4
votes
1
answer
2k
views
How to deal with passwords during automated deployment? [closed]
As responsible admins we know of common weaknesses like
CWE-260: Password in Configuration File http://cwe.mitre.org/data/definitions/260.html
CWE-522: Insufficiently Protected Credentials http://cwe....
- 633
0
votes
3
answers
3k
views
Move mail server to a new server with no downtime
We have a server that currently acts as a web, database and mail server. We would like to move mail to its own dedicated server.
So:
The address for the mail server is mail.example.com. It has A and ...
- 167
0
votes
1
answer
388
views
Network packets flowing both ways but still can't communicate
I have a linux box with two NICS:
eth0 192.168.11.14
eth1 192.168.12.14
My routing table is as follows:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref ...
- 219
1
vote
2
answers
1k
views
change configure -prefix in apache 2.2.18 installation linux
I have installed apache2.2.18 on my linux server.
However, while configuring it using ./configure –prefix=PREFIX command i gave a wrong prefix. I noticed it after running make install command as ...
- 11
0
votes
1
answer
451
views
Untrusted SSL certificates on CentOS VPS
I'm currently in the process of becoming PCI compliant and I have 6 warnings remaining. The one I'm particularly struggling with is "SSL Certificate Cannot Be Trusted IMAP (143/TCP)". I'm using ...
0
votes
2
answers
1k
views
Gnu parallel not utilizing all the CPU
I have a simple python script that read from stdin (a single line), do some processing (string parsing, no IO involved) and output to stdout
e.g. python parse.py < in.txt > out.txt
I have an ...
- 2,175
0
votes
1
answer
422
views
How do I allow users to add/modify files in a directory but not change the directory - Linux
How can I modify a directory so that it is owned by a group and users in that group can add and delete files and create sub directories but are unable to change the permissions on the parent directory?...
- 1,102
4
votes
2
answers
23k
views
why does sudo su; su tomcat doesn't switch to tomcat user?
In Redhat linux. from my user if I issue command
sudo su -> changes to root
su tomcat --> changes to tomcat user
Why does tailing the commands in single line doesn't work?
sudo su; su tomcat --> stil ...
- 141
1
vote
0
answers
204
views
Upgrade Raid 1 to Raid 0+1 and bootloader issue
I am trying to convert my current RAID 1 to RAID0+1 and facing issue in installing bootloader - please have a look what i am doing.
My current configuration is RAID1(2*10GB):
[root@localhost ~]# ...
- 11
0
votes
1
answer
612
views
Adding Logic to DHCP Relay Agent
In our environment we have 3 DHCP Servers used for PXE booting.
1 - FreeBSD PXE
1 - Linux PXE
1 - Disked Imaging (clonezilla-like device)
Each device requesting DHCP is on a separate subnet ...
3
votes
1
answer
3k
views
Redundancy: LVM+mdadm or LVM internal RAID
The task is to create LVM storage for virtual machine images. So LVM will be used in any case.
There are two ways LVM providing redundancy:
block mirroring
lvcreate -m 1 --mirrorlog mirrored -n ...
- 213
6
votes
2
answers
1k
views
LVM physical volume priority
Linux LVM can combine several physical volumes in one group and when spread space of this group among logical volumes.
If some slow devices will be added to group it may slow down all logical volumes....
- 213
0
votes
1
answer
8k
views
SSH problems - server unexpectedly closed network connection
Since yesterday I have problems connecting to my server using SSH/SFTP. I can only connect after a restart of my server. When I try to make a connection after a couple of minutes, I can no longer make ...
- 101
5
votes
2
answers
4k
views
Public-Key -or- Password & Google Authenticator for SSH Login
I found an article (http://www.howtogeek.com/121650/how-to-secure-ssh-with-google-authenticators-two-factor-authentication/) that explains how to configure OpenSSH to ask for a Google Authenticator ...
- 165
0
votes
1
answer
2k
views
Bacula errors in bacula-sd.conf
I'm new to Bacula and just finished an install on Ubuntu 14.04.
I have installed mySQL then Bacula. However getting the error below.
user@Bacula:/$ sudo bacula-dir -tc /etc/bacula-sd.conf
13-May 18:...
- 13
0
votes
0
answers
1k
views
Netatalk shared folder shows as readonly on OSX
I have a few Mac clients connected to a Linux server running Netatalk 3.1.1. The server is connected to an AD domain, the clients are currently not. Previously all users were connecting under a single ...
- 499
0
votes
2
answers
244
views
Hardware firewall for Linux web (and mail) server allows UDP connections to any local port from remote ports 53 and 123 -- is this safe?
I'm trying to tighten security on a linux web server. It has a hardware firewall with a default rule set and I noticed two rules that concern me:
remote port: 123; local port: ANY; protocol: UDP; ...
- 1
75
votes
6
answers
216k
views
What is the correct way to open a range of ports in iptables
I have come across articles advising for the following:
iptables -A INPUT -p tcp 1000:2000 -j ACCEPT
And others stating that the above will not work and iptables only supports multiple port ...
- 773
3
votes
2
answers
690
views
nftables alternative for iptables -F
Simply, is there any quick alternative of iptables -F command (that just "deletes everything") for nftables?
Such thing wouldn't have much theoretical purposes, but it's usually a lifesaver for ...
- 571
0
votes
0
answers
48
views
NGINX cache mis-behaving causing the system to go into a frenzy
We're using CentOS/nginx fastcgi_cache to cache requests to PHP files on our server. This file gets accessed very often and also updates very often as such it has 1s cache.
Usually when looking ...
- 143
4
votes
3
answers
5k
views
volume not found or not mounted when trying to umount
I'm attempting to detach Amazon EBS Volume from an Instance, and I can't figure out why the filesystem can't be found/isn't mounted.
On my EBS Volumes, the attachment information shows:
(Instance1):...
- 71
0
votes
1
answer
64
views
Run script on boot [closed]
Is there a way to run a .sh script ONCE when I boot? I know about the init.d folders, but there seems to be some weird special layout you must use for scripts there.
I only want to run two quick ...
27
votes
5
answers
90k
views
How to stop/prevent SSH bruteforce [closed]
I'm very new to network administration, so please regard that I'm not that experienced yet.
I have a Ubuntu root server with plesk panel.
Yesterday my friends and I noticed that the quality of ...
user219534
0
votes
1
answer
4k
views
On a Debian 7.5 rc.local won't be run at boot
I am struggling to figure out why rc.local won't be executed at boot time.
The file itself is executable, it is called from /etc/rc2.d
Also the file when from command line won't return any errors.
Any ...
- 1,821
6
votes
4
answers
8k
views
What is the correct escaping for autofs mount credentials files?
I have configured autofs on CentOS using /etc/auto.mymount. Something like this:
mymount -fstype=cifs,rw,noperm,credentials=/etc/auto.creds.svc_account ://winserver.domain.local/SharedFolder
This ...
- 121
2
votes
1
answer
705
views
Network ping replies: latency alternates low and high
I'm experiencing some troubles with one machine in my network. When I ping it the ping replies rotates like this :
64 bytes from 10.0.100.10: icmp_seq=156 ttl=62 time=100 ms
64 bytes from 10.0.100.10:...
- 602
3
votes
2
answers
2k
views
Install rsync on VMware ESX 4.1 server
I have a Red Hat Enterprise Linux Server release 5.1 (Tikanga)
VMware ESX 4.1 (Kandinsky), and my plan is to backup the files from the box to a NAS in another host. I have already resolve the ssh ...
- 31
1
vote
2
answers
7k
views
snmpwalk doesn't work with SNMP v3
We have a Cisco switch which we have been monitoring using Nagios over snmpv2 for ages. Recently our auditing team forced us to move to snmpv3 on all network devices.
The Cisco engineer came in and ...
- 421
-2
votes
1
answer
177
views
Identify VMWare Guest from within Linux Guest [duplicate]
Is there somewhere from a Linux guest that will show me if the VM is running on VMWare's hypervisor?
Ideally a method that doesn't require vmware tools to be installed... maybe something in /proc or ...
- 84.4k