I 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 RepliesI 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 Replies View RelatedJust installed centOS 52 x86_64 on a Core 2 Duo (E6750). From the /proc/cpuinfo I see that only one processor is detected. Any parameter on the BIOS to be changed?
View 2 Replies View RelatedDist: 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 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 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 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
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 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]...
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 RelatedHow 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 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.
Is there any way to limit x number of samba users by samba ? Say if there are already 5 samba users using the share, I would like to restrict any futher samba requests.. How do i do that ?
View 1 Replies View RelatedI really don't understand what's happening.I make a 3.5tb RAID array in Disk Utility, yet it makes it so that one partition is 3tb and the other is 500 gigs free!Why is that? Ext4 can do huge partition sizes I thought.
View 1 Replies View RelatedIs there a way to limit the speed that apache will send a page to a specific computer in my LAN? I would like to be able to test what my pages would be like if they loaded at 25KB/s for example. My Server is 192.168.0.2 and the other 'browser' computer is 192.168.0.4.
View 3 Replies View RelatedThis is happening on Ubuntu 9.10 serverI'm trying to increase the number of open files allowed for a user. This is for an nginx webserver where the current limit of 1024 is not enough.According to the posts I've found so far, I should be able to put lines into /etc/security/limits.conf like this;
Code:
* soft nofile 4096
* hard nofile 4096
[code]...
I have a problem with a PHP/Apache program.
The website creates a RPG character through a traditional Wizard. It calls itself with a hidden variable being the page number and tests which page and returns the page data with the page incremented.
Each page should be treated as a seperate page and so would be unique. I am echoing the contents of POST to the top of the page and so I can see variables being returned. When I get data from an Ajax query from page three it saves the data (23 post fields of no more than 25 characters for each field). Page four does the same but with less fields - but it is NOT returning the data - only four fields being those that were originally posted.
I cut/paste the function from section three to section four and changed the displayed text and the names of variables to test so there are no code errors, since page three works and is saved to a database.
So the only option is that there is a PHP or Apache2 issue when POST variables are returned? I am completely out of ideas as to why this would even be an issue or how it could possibly appear.
Is the number of variables an issue? This page is less than the previous page.... And the form is POSTed...
PS: I am getting NOTICE errors from PHP being the POSTed variables that are not displayed/returned... I used:
error_reporting (E_ALL ^ E_NOTICE);
to stop these form being reported but do I need to test each one? PPS: Using If Isset($_POST['xxx']) does NOT allow that variable through...
PS: I have the default Ubuntu 10.04 Apache2 with all the ubuntu 10.04 updates...
I have a number of servers I manage, and one of them is archiving old data that is never modified on a separate partition. This partition is at 100% capacity. A friend of mine says this is an unsafe way to keep this partition, even tho I don't plan to add any more data to it or change anything within. I know I can archive the data to dvd, but I'd like to keep the data online for my users.
What are your opinions on this? Can I keep this archive partition at 100% capacity? Or do I risk some sort of data corruption? Should I mount this partition as read-only to help prevent any corruption?
I successfully configured a VPN using IPSec(Openswan) and xl2ptd. While roughly following this guide (among countless others): [URL]
The VPN-Connection works fine, connecting to it is also a swirl, I can reach all that I want in the network, and also the gateway to the Internet works - everything being routed through that VPN.
Now my problem is actually the next steps, and I didn't succeed finding the right result on any possible search:
a) I want to limit, that the VPN-Connection is only used for distinct connections to hosts, that aren't in a "company subnet", but the IP's are publicly available. (Example: The Target-IP 8.8.8.8 allows per iptables, that only my VPN-Host 1.2.3.4 accesses it via SSH, and thus I only can access that Target-IP via SSH when I'm on the VPN). When actually browsing to the ubuntu-website, I want, that NOT the VPN-Connection is used but rather my normal connection (as a reference: i'm on a Windows-Client - not my choice, btw.)
b) I want to have several such "limitations" grouped, and give users 'access-rights' to certain hosts (Examples: Admin gets access to all on all ports Testers get access to some machines on distinct ports CEO gets access only to the mailserver via POP3 or IMAP
using kubuntu 9.04 on AMD 64,working with ISPconfig panel.I have postfix configured and have no problem getting mails with small attachments, but when they pass certain size I don't get them.Where can I configure this?
View 3 Replies View RelatedI'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?
I have a command line server that logs to stdout, which I start along the lines of ./server > log.txt
What I want to do is limit the size of log.txt, without modifying the server.
I am assuming there must be some kind of tool already that lets me do this, something like where I can pass in my server, the output file and a size limit? If so, can anyone enlighten me?
Running an nginx webserver on Ubuntu 10.04 lts In the process of trying to optimize the mysql, various tuning scripts keep telling me to raise the table cache. But they also say the table cache should stay below 1/3 of the open files limit. I can raise that in mysql, but I guess you're not supposed to raise it above the OS's open files max. So I'd like to raise it (found what appear to be solid instructions here: [URL] But... Post by Kees here says it's not safe to raise it [URL] at least, not safe under certain conditions. But I'm not clear on what the conditions are. is it safe or not? If I knew how to just raise it for mysql, I'd do that. But as you can probably see, I'm pretty new to all this. Don't want to wreck my server. (my current limit is the default 1024... wd like to go to 204
View 5 Replies View RelatedI understand winxp pro limit the inbound connection to 10 and win7 to 20. Is there a limit for ubuntu server?
View 2 Replies View RelatedI'm running nginx for static files and as a proxy server for a comet IM server on ubuntu Jaunty. On high load I'm hitting a limit of 1024 file descriptors. I've tried increasing this limit but still can't pass 1024. Does "more /proc/sys/fs/file-nr" gives me the global count of used file descriptors? Why do I see a maximum of 1024 open file descriptors in /proc/sys/fs/file-nr if this is the global count for the machine and each user should have at least 1024 allowed file descriptors by default? Is there a way to increase the limit while the server is running?
Some relevant info on my server:
sudo more /proc/sys/fs/file-nr
1024038001
sudo sysctl fs.file-max
fs.file-max = 38001
sudo nano /etc/security/limits.conf
...
* hard nofile 30000
* soft nofile 30000
I also added this to /usr/local/nginx/conf/nginx.conf:
worker_rlimit_nofile 10240;
Uncommented the following line in /etc/pam.d/su:
session required pam_limits.so
How to limit emails sent outside my domain or from a user in my domain with postfix to a valid user? i.e., bob can't send email as jane both from my domain and neither can send email to bob@hotmail.com as someone other then themselves. Using postfix with dovecot authentication through mysql.
View 1 Replies View RelatedI have an Ubuntu server running in our small office. Among its many duties is report generation. It uses PHP and DOMPDF (a PHP library for converting HTML/CSS to PDFs for printing). PHP's default memory limit of 32MB is not even close to being enough to pull large amounts of data from the database and generate images/tables/PDFs with that data.
I increased the memory limit to 64MB and that is adequate for reports under 3 pages or so (varies based on table complexity, images, etc). If any user tries to generate a report longer than that, PHP just throws a "out of memory" error and doesn't make the report.
My question is: what are the possible consequences of increasing the memory limit yet again to 128MB or maybe even higher? The server isn't terribly powerful. It has 2GB RAM and 4GB swap space. I know that isn't much but this is a small office and at most I can only see two or three people trying to run reports at the same time. As for security, apache is currently only serving pages in the local network, but sometime within the next year I'll probably have it hosting a public website (currently using a hosting service). Is a high memory limit a potential security risk when exposed to the internet?
EDIT: Sorry, PHP's default memory limit is 16 not 32 as I said. Question still stands, however