I am using ssh server to connect to my Ubuntu desktop. I opened the file sshd_config and change my port number of the server.I want to put a limit on the number of clients in the ssh server.
View 2 RepliesI am trying run audio conversion on my server that I want limited to a certain number of processes based on process name. I am using the following script but it isnt limiting the number of job like I want it to.
Code:
#!/bin/bash
$num_jobs = 13
while [ $(ps -A | grep -v grep | grep -c pacpl) -ge $num_jobs ]
do
sleep 1
[Code]...
More of a "Knowledge" question... Is their a limit to the number of reads a single file can take? Say for example I have a file named config.xml in an htdocs directory and a XMLReader function from PHP reads some value(s) out of this file for every connection of Apache or NGinx. Now suppose my site receives a gigantic spike in traffic (but Apache stays opertational through it all)... Is their a point at which the underlying system would simply not be able to open+read config.xml anymore??
View 2 Replies View Relatedapache virtual host to limit the concurrent connections of virtual hosts? Taking into account the host of each virtual user's home directory can also have more than one subdirectory, which should be restricted to a subdirectory. Is beyond the control of the operation of these sites in a subdirectory. Best local restrictions or limitations to the overall situation.
View 1 Replies View RelatedI have a server with 48 cores, 8 6-way Opteron CPU's. Ubuntu Server 9.04 only sees 32 processors. Is there a limit on the number of cores/processors that the server will use? Windows 2008 on the same server sees all 48 cores and the so does the BIOS, so this is unique to Ubuntu right now.
View 5 Replies View RelatedHow do I find the maximum number of concurrent connections (in any state)? I'm running RHEL5 2.6.18-194.26.1.el5. Also, does tcp auto tune affect the number of concurrent connections or is it mostly used for dynamic buffer size allocation?
View 3 Replies View RelatedI ran into a user today that indicated that their company only allows them to log in through a terminal session once (no multiple logins). On second try their login window terminates. They are using putty.Is this being accomplished through PAM or sshd ( or some other method)?
View 1 Replies View Relatedexcept is there is a way to enhance mod_limitipconn.c to ensure that apart from restricting one connection allowed from a given IP, also set so that an IP can only connect on every set interval ?e.g.restrict the number of connections from a given source IP to say once every 5 minutes or so?if not mod_limitipconn.c, any other mechanism to do the expected result?
View 2 Replies View RelatedWe've been experiencing sudden host server crashes minutes after starting a fourth virtual machine. Our setup looks like:
Dell Poweredge T300
1 x Intel Xeon X3323 Quad Core 2.5 ghz
16 GB Ram
CentOS 5.3 (64 bit)
Server is running a stripped down version of CentOS 5.3 (64-bit), running only the built-in Xen Virtualization Environment. There is no other services running on the server (not samba, httpd, sendmail, cups... nothing except Xen) We've created several virtual machines, and as long as we don't start a fourth virtual machine everything runs smoothly (impresive hardware).
Each virtual server is configured as:
PARAVIRTUALIZED
1 Virtual CPU
1 GB RAM
However, 5 minutes or so after starting a fourth virtual machine, the entire host server crashes and restarts itself. Are we limited by the number of cores on the host machine CPU (4 cores)? 1 for the host and 3 for virtual machines? We've read in forums about other Xen setups running up to 11 virtual machines on less powerful hardware? (a dual core server). Should we be using FULLY VIRTUALIZED virtual machines instead? Is the number of XEN virtual machines in fact limited by the number of cores? If so, how can someone run several virtual machines on a single core host?
By the way, we were replacing a previous Dell Server (Poweredge 2600 with 512 MB Ram and a single Xeon single core processor running Open Virtuozzo). We were able to run up to 16 virtual machines at the same time. Of course none of the machines endured hard work (testing environments, etc). But hey, my point is that we expected to get a much higher number of virtual machines on this new hardware.
what cloud computing is and i think it can help me with some of my clients i want to switch my clients from a normal ubuntu server to a ubuntu cloud. as of right now i have to send out a bill to them and if they dont pay i have to shut down there service till they pay. what i would like to do is to have a cloud where i can sell them based on what they use not a set price like it is now. and have them be able to pay there bill on the cloud and if they miss the bill then the cloud can shut off there service till its payed.
i dont know if this is possible and i have looked everywhere and all i can find is info on other businesses billing and now how to set up a cloud to do this. i wish there was some kind of tutorial for this. if anyone can direct me to some good notes/tutorials that would be very helpful. this could be a big changing point in my business if i can do this. it would save a lot of time and cash.
I'm thinking about some ways to limit access to my web-server. It runs Nginx and php in FCGI. The server contains a large amount of information. The data is freely available and no authentication is required but other companies might like to mirror it and use on their own servers.
The requests could be limited on different levels: IP, TCP, HTTP (by nginx) or by the php application. I found some solutions (like Nginx's limit_req_zone directive), but they do not solve the second part of the problem: there's no way to define a whitelist of clients who are allowed to use the data.
I thought about an intellectual firewall that would limit the requests on IP basis, but I'm yet to find such device. Another way was to hack some scripts that would parse the log file every minute and modify the iptables to ban suspicious IPs. It would take days and I doubt this system will survive, say, 1000 requests per second.
Perhaps, some HTTP proxy, like Squid, could do this?
In the last week or so, I've frequently been running out of X server client connection slots and getting "Maximum number of clients reached" errors. For example, I'm getting it right now and I'm running 3 pterms, Chrome, and Thunderbird; I've even killed my panel. 'xwininfo -root -children' produces what seems to be an absurd number of X clients (150-ish, when it's able to make a connection), even immediately after Gnome/Xfce startup.
It doesn't take long. A day at most. I've had this system up and running for months, and this just started happening. I did install some X development libraries (x11proto-core-dev, libmotif-dev, x11proto-print-dev, and x11proto-xext-dev plus their dependencies) about two weeks ago, but this problem has not been happening that long. I've installed other packages, but nothing that would seem to have any relation to this problem. I've logged out and in, rebooted, and changed from Gnome to Xfce, and none of the changes helped.
how many clients (pcs) can be tied to a U1 account?
View 1 Replies View RelatedMy server and clients (NFS and NIS) are in continuous attack via ssh. Somebody is trying to guess password and login, and making port 22 busy.What are different ways to stop this attack?I am thinking to block this ip in iptable but I have no good idea because I have not done this before. Any special consideration do I have to take while doing this thing? How is it done and which file does it modify?
View 14 Replies View RelatedI installed and configured LDAP server and client on RHEL5 successfully. Problem is that when I add more than one user on server and clients, It shows error 'invalid user'.When I run the command:-#chown -R user:users /home/user, It shows error 'invalid user'. by step for adding and modifying more users in ldap servers.
View 1 Replies View RelatedHow do clients handle offline syslog servers?Will the log files be buffered locally to be sent to the syslog server when it comes back online, or will any log data generated during downtime be lost in cyber space?
View 1 Replies View RelatedI'm trying to setup a server at home, it has some practical implications, but largely it is just to take a stab at it. But I need the help of someone with more experience than I in defining exactly what I'm looking to do.
Here's what I have: old PC running Gutsy server connected to router. Several laptops at home connected via wifi to router. All laptops running either Windows or Ubuntu. Here's what I'm looking for: The server centralizes file storage for all clients. I would likely incorporate a RAID and some synchronised imaging of the files. I also want the server to create disk images of the clients hdd, regardless of client OS.There would also be some shares that would be publicly accessible (myself and friends accross the country would be able to access the same drive).
So I was thinking something like what corporate environment would be nice, you log into a profile that exists on the server. Like a dumb client...all data would be stored on the server. But I'm thinking that's more like a network boot and wouldn't work via wifi (or would it?). Also that wouldn't lend itself well to laptops used on the road in areas without net access. now I'm thinking each client would have its own locally installed OS, and they would just access networked shares. I could store sensitive files on the shares, but that wouldn't provide complete backup solution for each client.
Without rambling on anymore, anyone care to throw out some ideas? I'm really just looking to see if I can do what I want. The focus is on centrallizing files, securley backing up data and client OS's and ability to restore said images quickly.
Dist: Fedora 14
SSHD: OpenSSH 5.5p1
I need to limit the number of ssh connections a user has. All the users are using tunnel only so their shell is set to /sbin/nologin The logins do not open a shell they just create the tunnel so /etc/security/limits.conf has no effect on them at all.
I tried setting 'MaxSessions 1' in sshd_config but either that doesn't not do what I expect it to or it plain does not work as even with a normal user I was able to open an unlimited number of sessions. I need a good secure way to limit each user to 1 ssh session without them having a shell but Im unable to find a solution.
I have a SSH server set up at home listening on port 22. I have hardened the server so it is pretty secure but I want to make it even safer by editing my iptables to rate-limit incoming connections and DROP false login attempts. I have tried these tutorials but I just cant get it to work:[URL]I want the debian-administration.org tutorial to work but when I try to add the first rule in terminal:sudo iptables -I INPUT -p tcp --dport 22 -i eth0 -m state --state NEW -m recent --setI get the following:Bad argument --set'I am new to iptables and I'm not sure if I'm doing something wrong when I try to set it up. I'm using Ubuntu 10.04.1 LTS with iptables v1.4.4.
View 6 Replies View RelatedI was nosing around in my /home folder and I noticed that the /.thumbnails directory had 38,000+ files in it. That number seem a bit excessive to me. Is there a way to limit the number of files that are allowed to be in that directory, and maybe delete the oldest files automatically when the directory reaches it's limit in order to make room for the new incoming files, so there are no "directory full" type of errors?
View 8 Replies View RelatedI'm looking for a solution for sendmail to limit the number of emails send per miniute per IP. For example all my local computer user with ip 192.x.x.x need to able to send 10 emails/minite (emails, not connections!. The rest of the world can send for example 200 emails/minute to the mailserver. If the amount of emails per minute is exceeded, sendmail needs to block receiving emails from the spesific IP. I want to do this to stop spaming from my local network. Is it possible?
View 1 Replies View RelatedI have a file with 200 000 lines and I want to append the fields of each line based on matching first field. The resulting file should have 70 000 columns but has "only" 18 000. The command I'm using is working perfectly with a smaller file, wich lead to 14 000 columns. Could there be a limit in number of fields that awk can handle ? Here's my awk command :
Code:
awk -F, 'END { for (k in _) print _[k] } { _[$1] = $1 in _ ? _[$1] FS $4 : $1","$4 } ' file > out
Also, this command writes ^M (windows line break) after each columns. Removing them is easy but where do they come from ? Working on Ubuntu 10.10
I have done nothing with the system, but starting this morning, i experienced a strange condition on my desktop. I'm unable to open any applications at all. It will close instantly.
When i tried to run from terminal, it will give me an error like this:
Quote:
I checked using
Code:
And i got around 234 which is too much that it takes almost all of the open files allowed. Logging out to text and brings back X will solve the problem, but it's only a temporary solution until X opens more sockets again. I'm running -Current (32 bit)
It seems that there's a hackish solution in here: [url]. Dunno whether it's a nice solution or not, but i'm willing to try it.
Does anyone know if there is a limit to the number of virtual guests you can have in kvm. RHEL has a limit of 4. RHEL AS is unlimited. What is CentOS?
View 1 Replies View RelatedI have a standard home set-up for my Ubuntu OS, and I would like to know whether its possible to cut out the repetitive prompts to enter the password, as when you connect to the internet or access files on a partition that's not home, or install new software.
View 1 Replies View RelatedI'm attempting to run a DHCP server on my home network to enable PXE booting for ethernet clients, but I'm having quite a few issues getting it all up and running. I'm not entirely sure what is wrong, but I keep encountering errors in syslog as follows:
Code:
Feb 27 02:26:46 servnerr-1 dhcpd: Wrote 0 leases to leases file.
Feb 27 02:26:46 servnerr-1 dhcpd:
Feb 27 02:26:46 servnerr-1 dhcpd: No subnet declaration for eth0 (192.168.1.3).
[code]....
Networking is not exactly my strong suit, but I would like to get this up and running if at all possible.
I was searching around and I stumbled upon a Linux Kernelix Sockets Local Denial of Service exploit.I downloaded the exploit, compiled it ran it to check if I am vulnerable.As I was expecting, the exploit instantly "killed" my Maverick system and I had to use the power button to reset my computer...Is there any way to limit the numberof allowed open sockets?I don't think that this can be done using /etc/security/limits.conf in a similar way of preventing the fork bombs
View 1 Replies View RelatedI with one problem to open files on terminal. By example, I open the thunar on terminal, see the error:
gustavo@universe /media/montagem $ thunar
(process:7902): Gtk-WARNING **: Locale not supported by C library.
Using the fallback 'C' locale.
Maximum number of clients reachedThunar: Cannot open display:
gustavo@universe /media/montagem $ ^C
How to number of connections for a single ip on port 80 to CentOS 5.5 with iptables? connlimit did not work on CentOS and nginx does not provide a module for that
View 4 Replies View RelatedMy Linux server which is running my company website have been hacked. Today I saw a number of clients (customers) with some fun characters entries on my database. Access denial on really clients. Please assist, am running Linux Ubuntu 9 and I dont know where to start troubleshooting this. let me confession that I am still on the learning curve on Linux
View 8 Replies View Related