Linux is the generic term for a UNIX-like open source operating system based on the Linux kernel.

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5
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70 views

Prepping a virtual appliance

Before converting a running virtual machine to an OVA (redistributable virtual appliance), what does one need to do to ensure it is in a ready state so the instances of the OVA don't bring along ...
3
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37 views

Debian staff group causes problems

We have an (old and grown) infrastructure of linux machines (mostly debian). For user authentication we use LDAP where we have defined several groups with different access rights. Unluckily one of ...
3
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61 views

TCP Window Scaling Problem over MPLS

After extensive troubleshooting why the TCP speed over an MPLS circuit is slow in one direction, I figured out that by adjusting the TCP window size the situation improved a lot. Maybe you can tell me ...
3
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0answers
53 views

TCP connection stuck in SYN_RECV state despite ACK received

My client and server are both internal machines. tcpdump on both client and server show all three parts of handshake are communicated, however netstat on server shows SYN_RECV, and on client shows ...
3
votes
0answers
390 views

Haproxy using 10GB Memory and 100% CPU with 50k connections

On a Ubuntu 14.04 x64 server, Haproxy uses 3.3 GB of memory and 6.8 GB of swap, while handling 52k connections. The CPU usage also keeps spiking to 100% before most of the traffic was redirected to ...
3
votes
0answers
100 views

Unusually high nfs_inode_cache

My server is experiencing a high usage of nfs_inode_cache = 11G , im trying to figure out what's consuming all this , i know already that directories with large numbers of entries and deep directory ...
3
votes
0answers
238 views

Linux cgroups cpuset w/ subs causes cgconfig not to start

I am having a problem trying to separate 2 groups using cpuset subsystem. This works fine, however if i go to add a subgroup to that group (in this case -- user1), cgconfig will fail to start with ...
3
votes
0answers
108 views

VMXNET3 nic loses the ability to update ARP table after N hours

I have a fedora 18 VM that stops updating the arp table on eth1 after running for a number of hours to days. There are other VMs on the same hypervisor that can access all of the same networks without ...
3
votes
0answers
126 views

timing issue after route add/delete (route not used)

I have an application that is running a raw IP socket, destination of this socket is governed by routes installed via the 'ip route add' command. These routes can change during the lifetime of a ...
3
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0answers
130 views

Syslog-ng not logging on debian

I have syslog-ng running but it does not seem to be logging to /var/log anymore. Looking at the logs it apparently used to awhile back: -rw------- 1 root root 0 Sep 8 00:55 messages ...
3
votes
0answers
188 views

snmp MIB-TCP::tcp not showing any usage

I am trying to configure MRTG on all of my servers for making a network weathermap, this requires running SNMP which MRTG gets the information from. So, I installed it on two servers the exact same ...
3
votes
0answers
78 views

reprepro use when multiple sources have the same codename

I'm investigating the use of reprepro to control what updates get propagated to our servers, and when. The idea is to vet updates by Debian and Ubuntu, and only apply the ones we choose. We want to ...
3
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1k views

NAT64 configuration with tayga on Debian 6

I'm trying to implement NAT64 with tayga on my server and came to a point where I'm not sure how to proceed. My server is connected via one IPv4 address and one /64 IPv6 address block to the ...
3
votes
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224 views

Samba4 locked pst files

i have a samba4 server that holds my clients outlook pst files, if the outlook client or the machine crashes i must go to the server to kill the PID manually. i saw there was "reset on zero vc =yes" ...
3
votes
0answers
664 views

Intermittent NFS lockups on Isilon cluster

We have an Isilon cluster with 8 IQ 12000x nodes which exports storage via several NFS shares for a handful of Linux and Solaris clients. There is a Linux system that has one of these NFS filesystems ...
3
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0answers
746 views

How do I configure OpenSwan to allow pure IPsec (not L2TP) connections from an iPhone?

Similar to this question, I want to configure an IPsec server on Linux which will accept connections from the iPhone. However, unlike the other question, I want to be able to test with pre-shared keys ...
3
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0answers
779 views

how to tune NFS client on MacOS to get Linux like performance?

I have a NFS server running Linux and exporting a couple of shares. Both Linux and MacOS clients connect to the server, and while with the Linux clients I get ~ 75MB/s write speed, the MacOS clients ...
3
votes
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1k views

How to measure dcachesize usage (and reduce it)

I have a VPS running CentOS 5.7 (Final), 32-bit. Right after boot, when I run # cat /proc/user_beancounters I see that my dcachesize usage is at about 4100000, while my VPS is set up with a limit of ...
2
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36 views

Linux NFS server refuses blocking locks

So I have this problem. This horrible, awful problem. I have a set of Linux NFS servers (in a NFS/CIFS cluster using CTDB) that refuse locks… only when the lock is blocking. If it's a non-blocking ...
2
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28 views

IPsec - strange behavior

I have set up site-to-site ipsec connection between linux(debian) and mikrotik router. The tunnel is up linux configuration: config setup interfaces=%defaultroute keep_alive=60 ...
2
votes
0answers
133 views

Network Layer 7 Deep Packet Inspection linux solution that isn't a all-in-one distro?

Overview: I have software that has our Edge/DNS servers hardcoded into them, DNS queries returned from DNS servers are not being masked properly. I need the DNS entries that are returned from BIND ...
2
votes
0answers
82 views

RPC timeout between 2 linux servers

There are 2 servers in different routed networks. I can ping, ssh from one to another via router, and nmap utility shows opened tcp:111 and udp:111 ports. Also both servers show something like that: ...
2
votes
0answers
38 views

Setting quotas from a Linux client on a SmartOS (OpenSolaris) based ZFS server

I have a SmartOS (an OS based on OpenSolaris) server running a few virtual machines. One of the ZFS volumes is shared as an NFS volume and mounted on one of the VMs which is running Debian wheezy. ...
2
votes
0answers
60 views

How long does a Ubuntu shutdown script have during a shutdown?

I have a script setup in /etc/rc6.d/ and /etc/rc0.d/ to be executed when the machine goes down. However, there seems to be a strict time limit for how long those scripts can run. (This makes sense, ...
2
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0answers
46 views

Samba: Authenticate only local accounts over AD?

I have a samba server where I create all the linux accounts and corresponding SMB accounts via a application I built. I manage all the permissions for all of our shares via ACL's also using the ...
2
votes
0answers
57 views

Why “scope link” ipv6 address can be pinged via interfaces which they are not active on

[root@2_01 ~]# /sbin/ip -6 addr show pubeth0 inet6 2001:1::6/64 scope global inet6 2001:1::1/64 scope global inet6 fe80::20c:29ff:fe69:f9e8/64 scope link [root@v2_01 ~]# /sbin/ip -6 addr show ...
2
votes
0answers
44 views

Cleaner way to restart daemontools services

In our product, we had created services using daemontools. One of my service looks like this, /service/test/run /service/test/log/run (has multilog command to log into ./main dir) ...
2
votes
0answers
210 views

How to provide external access to only the Git projects (clone/pull/push) of an internal GitLab deployment

We have set-up a GitLab server (GitLab 7.0 Community Edition). It is up and running and our colleagues can use it within the LAN (the IP address and Host are only visible from the LAN). Some of the ...
2
votes
0answers
110 views

ping: sendmsg: Operation not permitted (sometimes)

On a Ubuntu 14.04 running Haproxy, after a service haproxy reload, Haproxy is suddenly reporting all servers behind it as down. After some digging around, I noticed that ping is not working properly, ...
2
votes
0answers
357 views

Docker: Permission denied on folders added with ADD

I'm trying to configure a postgresql installation using docker. FROM ubuntu:13.10 ADD . /db # install postgres # ... RUN chown postgres:postgres /db -R && \ chmod 700 /db -R USER ...
2
votes
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109 views

runnning systemd without PrivateTmp, PrivateNetwork and PrivateDevices (in docker - unprivileged mode)

I am happily running systemd inside a docker container, however, it requires CAP_SYS_ADMIN in order to dynamically create private tmp mounts. I have attempted to disable the PrivateTmp, ...
2
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87 views

actual disk iops and write merging

/dev/sdb has LVM and exposes a single logical volume, dm-0. While writing to dm-0, /proc/diskstats reports: # of writes completed sdb 29646717 dm-0 131315099 # of writes merged: sdb 101668283 dm-0 ...
2
votes
0answers
48 views

A testing framework for Linux server configuration management

We are a medium sized shop that uses Puppet for Linux configuration management. Since we are a small shop, it's difficult to deploy and maintain DTAP environment. We normally perform manual testing ...
2
votes
0answers
28 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
2
votes
0answers
148 views

Linux (Debian 7 x64) swapping activity despite lots of free memory

Yes, I have reduced vm.swappiness a lot: % sysctl -a | grep swap vm.swappiness = 1 Memory is mostly free: % cat /proc/meminfo | head MemTotal: 8070592 kB MemFree: 2619580 kB ...
2
votes
0answers
63 views

How do I get the file name corresponding to an NFS file handle on Linux?

I have tcpdump output of some NFS traffic, it shows which file handles are being read or written. I'd like to know which files they correspond to. There's got to be an existing tool which will list ...
2
votes
0answers
288 views

How to find/kill long running mongo scripts

I think I have a long running mongo script tanking my database, but I'm not sure. I was connected to the linux server via SSH and I ran the script like so: mongo my_database my_script.js It started ...
2
votes
0answers
329 views

squid transparent proxy https

i hope someone can help me. i have this problem: squid is running as a ssl transparent proxy, and at the moment it's receiving all the traffic with these two iptables rules: iptables -t nat -A ...
2
votes
0answers
79 views

Lots and lots of kernel log entries: iint_free: readcount: -1, iint_free: writecount: 1

I am getting tons of log entries of the form Mar 2 00:44:10 SRV123 kernel: iint_free: readcount: -1 Mar 2 00:44:10 SRV123 kernel: iint_free: writecount: 1 Mar 2 00:44:10 SRV123 kernel: iint_free: ...
2
votes
0answers
332 views

How to mount share in pam_mount.conf.xml depending of OU

I have a Microsoft Windows domain and I want to add the ubuntu machines with Likewise-Open. There is no problem with that, but in my windows machines I have a GPO that mount a net share depending of ...
2
votes
0answers
296 views

Adaptec pm80xx Driver Drops Drives Randomly

I'm building a ZFS NAS using an Adaptec ASA-71605H HBA on Ubuntu 12.04.4. Modern Linux kernels ship with the open-source version of the required pm80xx kernel module. Adaptec provides a driver for ...
2
votes
0answers
47 views

Change the logical volume

I am quite new this snapshot process. Let, I have three logical volumes as A, B, C. I worked on logical volume C. But accidentally when I restart the system, it goes to the snapshot A. How can I ...
2
votes
0answers
100 views

RAID1 disks “forked”, now duplicate

I have got a server hosted by OVH, which is configured to have a soft RAID1 array, /dev/md0, that holds a LVM PV. There is another /dev/md1 array, which was supposed to be the /boot, but which is ...
2
votes
0answers
215 views

ZFS on RedHat configuration

I have to set up a ZFS storage appliance (Oracle ZFS Storage ZS3-2) with NFSv4. The NFS is mounted on a Redhat 6.5 cluster, where the linux users are created (they don`t exist on the appliance). ...
2
votes
0answers
90 views

How to debug sluggish process performance

I have a test application which writes a string to a file 10000 times. I run this on two servers and I get totally different results. [SYSTEM 1] $ time ./test_depth real 0m0.152s user ...
2
votes
0answers
2k views

How to recover an mdadm array on Synology NAS with drive in “E” state?

Synology has a customized version the md driver and mdadm toolsets that adds a 'DriveError' flag to the rdev->flags structure in the kernel. Net effect - if you are unfortunate enough to get a array ...
2
votes
0answers
306 views

Please help recovering lost volume group

After a reboot, the volume group on my server completely disappeared. [root@dal01 log]# vgdisplay No volume groups found [root@dal01 /]# lvdisplay No volume groups found [root@dal01 ~]# pvdisplay ...
2
votes
0answers
871 views

Linux - NTP stopped working after recent update

A few days ago I had ntp setup on my network, and everything was running fine. One node was set to sync with upstream servers, and the rest of the nodes from the one set to sync upstream. Yesterday I ...
2
votes
0answers
308 views

NFS server export list empty

After upgrading my router, I am unable to mount NFS shares from a Debian server on an OS X client. I have updated /etc/exports according to the new IP address of the client (first line previously ...
2
votes
0answers
144 views

How can I use a Linux BIND DNS server for my Active Directory forest?

I am trying to setup an Active Directory forest that uses a Linux BIND server for DNS. The goal is that the Domain Controller (DC) to be able to make entries in the /etc/bind/db.foresta.net file from ...