Search Results

Search found 23127 results on 926 pages for 'based'.

Page 258/926 | < Previous Page | 254 255 256 257 258 259 260 261 262 263 264 265  | Next Page >

• AWS: Multi-region setup using single RDS instance

  - by Ion

  I'm trying to scale our web application (PHP, MySQL, memcache) in a multi-region scheme. Currently we are using a setup with two EC2 instances behind an ELB and an RDS instance, all of them in US-EAST (Virginia) region. We would like to have a presence in the EU (Ireland) region as well. This means at least a new EC2 instance there (identical to the others, serving the same application). I have copied the desired AMI, setup the new instance, setup a same ELB configuration (required for SSL termination) and configured latency-based routing in Route53. And it works as suggested. But, clients from EU have speed problems. This is due to the fact that the EU EC2 instances connect to the US-based RDS instance. As far as I know Amazon has not yet enabled RDS multi-region replication. Do you have any suggestions on how to properly speed up the whole setup while using the single RDS instance? Also, any ideas in general on how to scale things up? Ideally we would like to continue using the RDS technology for various reasons. Nevertheless, I am open to suggestions (I guess the next idea would be to host our own MySQL servers).

  Read the article

• Route return traffic to correct gateway depending on service

  - by Marnix van Valen

  On my office network I have two internet connections and one CentOS server running a website (HTTPS on port 443). The website should be publicly accessible through the public IP of the first internet connection (ISP-1). The other internet connection, ISP-2, id the default gateway on the network. Both internet connections have routers (the household-kind) with NAT, SPI firewalls etc. The router on ISP-2 is a Netgear WNDR3700 (aka N600) with original firmware. The problem is that the website is unreachable. Looks like incoming traffic on ISP-1 will reach the server but the returning traffic is routed through ISP-2, effectively making the site unreachable. As far as I can tell I can't do port based routing on the WNDR3700. What are my options to make this work? I've been looking at implementing an iptables / routing based solution on the server itself but haven't been able to make that work. Update: Note that the server has one network interface connecting it to both routers.

  Read the article

• Best way to build / implement a corporate developer Linux distro with multiple kernels?

  - by Garen

  At work we have Linux users who understandably prefer using Ubuntu. Problem is, we also have developer tools that only work with 'officially' supported Linux distributions that use much older 2.6.18 based kernels. (And even if they worked with newer ones, the vendors could always say they won't "support" the software unless it's on one of their 'officially' supported platforms.) We could of course just tell them to use CentOS or something else 2.6.18-based, and I'm sure their response would be something like: "you can take Ubuntu from our cold, dead hands." :) Which brings to me some questions--is there any good/easy/recommended way to run something like Ubuntu as a host VM and Centos 5.x as a guest OS (with which system--Xen,KVM,VMWare, ...?), and then roll that into our own custom internal distribution that could be easily installed? KVM looks like a good high-performance option just recently included in RHEL 5.4, but if hardware support for virtualization like Intel-VT or AMD-V is necessary, then I'd guess only those folks with fairly new PCs will be able to do it. Would be very interested to hear how anyone else has addressed this kind issue. EDIT: The target audience / users of this kind of system would be developers, each one needs to run locally licensed commercial software, so building out some separate beefy central machines isn't an option unfortunately due to license restrictions. Even if that weren't the case, a couple developers could quickly eat up the resources with parallel builds. :) Ideally, I was hoping there was some step-by-step guide out there to build your own pre-built distribution that had e.g. CentOS 5.x and Ubuntu Desktop as a guest.

  Read the article

• mod_rewrite not working for subdomain in Apache2

  - by Matt

  Hi, I'm having some trouble with mod_rewrite. So I'm implementing it through .htaccess, and I can get it working on my main vhost, domain.com - what I want it to do is rewrite http:// domain.com to force it to https:// domain.com, which it does well. I want to have name-based vhosts for the one IP with the following redirects: (I'm breaking up domain names with a space because otherwise serverfault recognises them as links) http:// domain.com -- https:// domain.com http:// staging.domain.com -- https:// staging.domain.com http:// test.domain.com -- https:// test.domain.com http:// beta.domain.com -- https:// beta.domain.com domain.com redirects to https:// domain.com, but staging.domain.com doesn't, although I can access https:// staging.domain.com. The .htaccess is identical for both, just with the domain name different. It doesn't seem to do any rewriting at all for staging.domain.com, I've tested this by trying to get it to rewrite to www.google.com. I have a wildcard DNS record, *.domain.com which points to the domain IP. Is there a particular way I should have the virtualhosts configured to allow this? I keep reading in the Apache documentation that it doesn't support multiple SSL name-based vhosts. But I can access both https:// domain.com and https:// staging.domain.com just fine. Any thoughts? Thanks to everyone for your help with this.

  Read the article

• Can My Personal GMail Query A Remote LDAP Server?

  - by Maarx

  I have a personal GMail account, from which I frequently send e-mail to a great many various users of a specific business. The corporation has been kind enough to provide me with the credentials to access their LDAP server, with which I would like my GMail web client to be able to auto-complete partial addresses or names for which that LDAP server has an entry. Is there any way I can get a personal GMail account (or it's corresponding entire Google account) account to incorporate an LDAP server into it's Contacts? If I cannot get it to query dynamically and on-demand, is there an idiot-proof way (assuming the client permits, which they may not) to query the LDAP server for it's entire database, save it, and bulk import it to GMail? Perhaps, even, something I could set to repeat periodically (weekly, perhaps), without human interaction? If I did the latter, I assume it would be trivial to import all of these contacts under a single category that could be easily manipulated from within the GMail web-based client. I have been a staunch user and supporter of the GMail web-based client since it's instantiation, but this one is kind of a deal-breaker for me. If it's impossible, what do you suggest I do?

  Read the article

• SBS2011 Standard DNS suddenly not resolving some domains

  - by Matt

  Suddenly today I am unable to resolve common domains like serverfault.com, facebook.com; but other domains like google.com, cnn.com work fine. This is on a client machine (Win7 Pro) connected to an SBS2011 Standard domain. The only DNS server is the SBS2011 server. The same domains work fine on all client PCs I have tried, and the same ones do not work. Using nslookup, I get 'no such domain' errors for facebook.com, and the correct DNS entries for the ones that do work. When I add Google's Public DNS to my client PC as a backup (primary = local SBS server, secondary = 8.8.8.8), everything works fine for my client PC, but querying from the SBS server directly or from other client PCs are broken (so I don't believe it's a firewall issue). My main question is how can I see what servers the SBS2011 server queries if it doesn't know about a domain? There is nothing in our firewall logs that say it blocked any DNS-based packets, but I also wanted to query based on the IP/FQDN on the servers that the SBS server was likely to contact to find out about facebook.com for example. Update 23/05/2012: It appears DNS is working again this morning for the affected websites. Both the DC on its own and all client PCs can once again access the websites that were not loading last night, as well as the websites that were working. I haven't changed anything overnight, so it appears that there was some kind of temporary glitch, but I can't understand what would have caused it on the network.

  Read the article

• How can I install git on RHEL 6?

  - by JR.Xyza

  I'm trying to install Git on a RHEL6 development server, I have experience with Ubuntu but this is my first time working with RHEL (I'm a developer trying to fill in for a recently departed Linux Sysadmin). I've set up two additional repos (EPEL and IUS) for other packages needed for a Magento install. Output of yum repolist: [root@box]# yum repolist Loaded plugins: product-id, security, subscription-manager Updating certificate-based repositories. repo id repo name status epel Extra Packages for Enterprise Linux 6 - x86_64 7,841 ius IUS for RHEL 6Server - x86_64 135 Most of what I've read indicates a simple 'yum install git' should work with EPEL enabled, but I get the dreaded [root@box]# yum install git Loaded plugins: product-id, security, subscription-manager Updating certificate-based repositories. Setting up Install Process No package git available. Error: Nothing to do Same goes for git-daemon, etc. I've tracked down a number of git RPMs such as this one at repoforge but they require a train of dependencies that seems to never end. I've also toyed with compiling it manually but the rabbit hole to get make working seems to go even deeper. I'm convinced there's a simple oversight somewhere keeping me from being able to install from the EPEL repo, but I'm a rookie at all this. Thanks in advance for help/pointers/additional resources.

  Read the article

• Network structure --> Server 2k8r2 <--> Livebox <--> Router <--> Other PCs

  - by Yusuf

  I have a Livebox connection to the Internet and I have set up my network as follows: - Livebox <--> Win2k8R2 Server - Livebox <--> Netgear N150 Router - Router <--> Other PCs Therefore, in my LAN, - the Livebox has IP address 192.168.1.1, - the Router 192.168.1.12 (when accessed from the Livebox or the server), - the Router 10.0.0.1 (when accessed from the PCs connected to the Router), - the server 192.168.1.2, - the PCs 10.0.0.x I was using a previous configuration, which was as follows: - Livebox <--> Netgear N150 Router - Router <--> Win2k8R2 Server - Router <--> Other PCs Everything was simple, and I just had to forward all ports for incoming connection on the Livebox to the Router, and then forward the specific ports to the Server as needed (it must be however noted that any server I use is found on the Win2k8R2 server itself). In this previous configuration, the IP addresses were as follows: - Livebox 192.168.1.1 - Router 192.168.1.12 (when seen from Livebox) - Router 10.0.0.1 (when seen from server & PCs connected to it) - Server 10.0.0.2 - PCs 10.0.0.x So now of course, my port-forwarding does not work anymore since the server is not connected (directly) to the Router. What I would like to know is how do I configure the Livebox and Router to still have the features like before? From what I understand of networks (which is very limited, btw), I see these options: Make the router assign IPs like 192.168.1.x (but then I want the forwarding to be done from the router itself, is it possible?) The forwarding on the router to the server uses IP address 10.0.0.2. I could change it to 192.168.1.2 (Is that even possible, does it work?) Forward all ports from the Livebox itself to the server, and then manage them there (Is software-based port-forwarding as secure as hardware-based?)

  Read the article

• Choice of filesystem for GNU/Linux on an SD card

  - by gspr

  Hi. I have am embedded ARM-based system running on an SD card. It's currently Debian GNU/Linux using ext3 as filesystem. As I'm about to reinstall the system, I started wondering about changing to a more flash-friendly filesystem. I've heard about JFFS2, YAFFS2 and LogFS, and they all seem suited to the job. Which one would you recommend? Also, I've heard there have been a lot of ext4 improvements to better suit SSD disks; am I to interpret that as running ext4 should be just fine? What do I need to think especially about in that case? I guess the usage of the system is important. But for the sake of generality, imagine it'll do standard desktop stuff (even though it is infact a small ARM-based system). Thanks for any replies. Edit: Wikipedia tells me (in a "citation needed" statement) that Removable flash memory cards and USB flash drives have built-in controllers to perform wear leveling and error correction so use of a specific flash file system does not add any benefit. Thus, I'm leaning towards sticking with an ext filesystem.

  Read the article

• optimal folder structure for storing 100k files on a USB drive

  - by cherouvim

  I need to store 100k files (around 40GB) in a USB drive. Each file has a unique int id (e.g 45000). Option one is to put all files in a single folder: root/ root/1.pdf root/2.pdf root/3.pdf ... root/567.pdf root/568.pdf root/569.pdf ... root/10001.pdf root/10002.pdf root/10003.pdf ... root/99998.pdf root/99999.pdf root/100000.pdf Option two is to create a [1-9][0-9]* folder hierarchy based on that id: root/ root/1/file.pdf root/2/file.pdf root/3/file.pdf ... root/5/6/7/file.pdf root/5/6/8/file.pdf root/5/6/9/file.pdf ... root/1/0/0/0/1/file.pdf root/1/0/0/0/2/file.pdf root/1/0/0/0/3/file.pdf ... root/9/9/9/9/8/file.pdf root/9/9/9/9/9/file.pdf root/1/0/0/0/0/0/file.pdf Which option will scale better? I can understand that the second option will require tons of folders but each folder will at most contain 10 folders and 1 file. Maintenance will not be an issue since everything will be controlled by an application. Note that this is a USB drive on linux and based on the above I'd also like to know whether I should go with FAT32 or NTFS.

  Read the article

• Why are my Windows 7 updates continuously failing?

  - by Chris C.

  I'm an advanced level user here with an odd issue. I have two Windows Updates that are failing to install, every single time. I'm getting a mysterious "Code 1" error on both updates, an error for which I'm having difficulty finding a solution. The updates in question are: Security Update for Microsoft Visual C++ 2008 Service Pack 1 Redistributable Package (KB2538243) System Update Readiness Tool for Windows 7 for x64-based Systems (KB947821) [May 2011] Because these updates are failing, the Shut Down button in my start menu always has the shield icon next to it, indicating that "new" updates will be installed on shut down. But, of course, they'll fail and when the PC is restarted, the shield icon is still there. When checking the update history and viewing the details of the failed updates, I get the following: Security Update for Microsoft Visual C++ 2008 Service Pack 1 Redistributable Package (KB2538243) Installation date: ?6/?29/?2011 3:00 AM Installation status: Failed Error details: Code 1 Update type: Important A security issue has been identified leading to MFC application vulnerability in DLL planting due to MFC not specifying the full path to system/localization DLLs. You can protect your computer by installing this update from Microsoft. After you install this item, you may have to restart your computer. More information: http://go.microsoft.com/fwlink/?LinkId=216803 and: System Update Readiness Tool for Windows 7 for x64-based Systems (KB947821) [May 2011] Installation date: ?6/?28/?2011 3:00 AM Installation status: Failed Error details: Code 1 Update type: Important This tool is being offered because an inconsistency was found in the Windows servicing store which may prevent the successful installation of future updates, service packs, and software. This tool checks your computer for such inconsistencies and tries to resolve issues if found. More information: http://support.microsoft.com/kb/947821 About My System I'm running Windows 7 Home Premium 64-bit. This is a custom PC build and the OS was installed fresh, not an upgrade from a previous version. I've been running this system for about four months. Windows Updates aside, the system is usually quite stable.

  Read the article

• In which order does Excel process its formulae?

  - by dwwilson66

  I've got a fairly large spreadsheet with major calculations going on, and it's starting to slow down every time a value that's part of a calculated field is modified. I'm in the process of optimizing the file, adding arrays where I can, and seeing where I can shave off a few milliseconds here and there. Let's say there's data in Columns A-H. Column H is set based on relationships between values in Columns A, B and C, which change dynamically from an outside program. Users enter the data in Column F. Formulas in D & E calculate relationships between F & H and H & D, respectively. How does Excel manage formulae in the case, for instance, where they're dependent on data further into the sheet? Will my value in H be available the first time that the formulae in D & E calculate? or, will D & E calculate based on an old value for H, because H's update hasn't happened yet? Are there any efficiencies to be gained by positioning dependencies in particular rows or columns in the speadsheet? Do positions above and left the current position get processed sooner than things below and to the right?

  Read the article

• In Windows 7, why won't my display stay off despite the power settings saying it should?

  - by Jer

  I'm completely stumped by this. My simple use case is that when I'm in bed, I use a cordless mouse to browse the web, watch videos, etc. - the monitor is across the room. When I'm going to sleep, I want to shut the monitor off. I also want to be able to turn it back on in the morning. I just want to turn the monitor off and on using only the mouse. I thought of creating a power setting that turned the monitor off asap (the shortest amount of time is one minute; that's fine). I have one that does this. It worked great for almost a year on my old XP machine, and for about four months on my new Windows 7 laptop (which I essentially use as a desktop). All of a sudden a couple weeks ago, it just stopped working - my monitor won't turn off on its own anymore. Here are the settings: I tried other options. Based on the advice here I tried nircmd. This seemed great. I created a shortcut with the command line: "C:\Program Files\nircmd\nircmd.exe" cmdwait 1000 monitor off I click this, and in one second the monitor goes off. However about five seconds later it turns back on, and I've been extra careful to make sure the mouse isn't moving. I have no idea what's going on. Based on both of these things, my only guess is that something could be running in the background which somehow makes the computer think it's in use. I've tried killing as many programs as possible but I still get the same behavior. Any advice? I'm mainly curious about how to debug, but am open to other suggestions about turning the monitor off and on with just the mouse as well.

  Read the article

• SSH attcack CentOS Amazon EC2

  - by user37143

  Hi, I run a few Rightscale CentOS AMI based instances on Amazon EC2. Two months back I found that our SSHD security is compromised( I had added host.allow and host.deny for ssh). So I created new instances and done an IP based ssh that allows only our IPs through AWS Firewall(ec2-authorize) and chnaged the ssh 22 default port to some other port but two days back I found I was not able to login to the server and when I tried on 22 port the ssh got connected and I found that sshd_conf was changed and when I tried to edit sshd_config I found root had no write permission on the file. So I tried a chmod and it said access denied for 'root' user. This is very strange. I checked secure log and history and found nothing informative. I have PHP, Ruby On Rails, Java, Wordpress apps running on these server. This time I did a chkrootkit scan and found nothing. I renamed the /etc/ssh folder and reinstalled openssh through yum. I had faced this on 3 instances on CentOS(5.2, 5.4) I have instances on Debian as well those working fine. Is this a CentOS/Rightscale issue. Guys, what security measures I should take to prevent this. Please support me this is very critical. Thanks

  Read the article

• Xen or KVM? Please help me decide and implement the one which is better

  - by JohnAdams

  I have been doing research for implementing virtualization for a server running 3 guests - two linux based and one windows. After trying my hands on Xenserver, I am impressed with the architecture and wanted to use the opensource XEN, which is when I am hearing a lot more about KVM, about how good it is and it's the future etc. So, could anyone here please help me answer some of my queries, between KVM and XEN. Based on my requirement of three VMs on one server, which is better for performance - KVM or XEN, considering one the linux vm's will works a file-server, one as a mailserver and the third one a Windows server? Is KVM stable? What about upgrades.. What about XEN, I cannot find support for it Ubuntu? Are there any published benchmarks on both Xen and KVM? I cannot seem to find any. If I go with Xen, will it possible to move to KVM later or vice versa? In summary, I am looking for real answers on which one I should use.. Xen or KVM?

  Read the article

• Looking for easiest, most simple solution to run a customised DNS Server for my local network on Windows 7.

  - by Jamie G

  I need to forward some websites, such as http://testing.server/ to an fixed IP address on my local network. I can do this easily on one computer using the hosts file. However, I need this to work for all machines on my network. I think the best way to do this will be to setup my own DNS Servers and add the custom DNS settings there. However, I'm looking for the simplest way possible to do this - I really don't want to spend hours setting up Unix Servers and running tricky terminal based scripts just to do this! My server is a standard Windows 7 machine. My dream would be a nice simple windows program with a GUI where I could input my ISP's DNS server and it would use those records, unless I had specifically set up my own DNS for a domain to use instead. If it had a web based admin system that was accessible from another computer on the network that would be even better. Does anyone know of anything that can do this? Many thanks indeed.

  Read the article

• What is the risk of introducing non standard image machines to a corporate environment

  - by Troy Hunt

  I’m after some feedback from those in the managed desktop or network security space on the risks of introducing machines that are not built on a standard desktop image into a large corporate environment. This particular context relates to the standard corporate image (32 bit Win XP) in a large multi-national not being suitable for a particular segment of users. In short, I’m looking at what hurdles we might come across by proposing the introduction of machines which are built and maintained by a handful of software developers and not based on the corporate desktop image (proposing 64 bit Win 7). I suspect the barriers are primarily around virus definition updates, the rollout of service packs and patches and the compatibility of existing applications with the newer OS. In terms of viruses and software updates, if machines were using common virus protection software with automated updates and using Windows Update for service packs and patches, is there still a viable risk to the corporate environment? For that matter, are large corporate environments normally vulnerable to the introduction of a machine not based on a standard image? I’m trying to get my head around how real the risk of infection and other adverse events are from machines being plugged into the network. There are multiple scenarios outside of just the example above where this might happen (i.e. a vendor plugging in a machine for internet access during a presentation). Would a large corporate network normally be sufficiently hardened against such innocuous activity? I appreciate the theory as to why policies such as standard desktop images exist, I’m just interested in the actual, practical risk and how much a network should be protected by means other than what is managed on individual PCs.

  Read the article

• Emails sent from Coldfusion using the same SMTP/Exchange server works from one machine but fails for another

  - by Peter Herdenborg

  First, apologies if this question is too vague or has too little information to really be answerable. I am not normally working with these issues, and I don't have full access to the environment. However, the hosting provider seems to have a hard time tracking down the issue, so I am hoping that someone can at least provide me with some qualified guesses about the most likely problem. Here goes: A client I work for has a hosted IT environment, based on virtual machines running Windows 2008 R2 Standard. Our website, based on Coldfusion 9 was recently migrated from one virtual machine to another, and though Coldfusion is configured in the exact same way, using the same SMTP server, i.e. the client's Exchange server hosted in the same environment and in the same AD as both web servers, sending emails to external recipients is no longer working. It is still working fine when testing from the old machine. This is what I've learnt so far (all emails are sent using a valid from-address on the client's domain): Emails sent to other recipients on the same domain are delivered without any problem. Emails sent to external recipients on other domains are never delivered. When sending emails to both internal and external recipients, no emails are delivered. When receiving one of these emails to an internal address, the sender is now indicated as "[email protected]", while when sent from the old machine, it used to say just "sender". This seems to me that it could hint that the Exchange machine "recognizes" the old web server while it is a stranger to the new. In Coldfusion's mail log, all messages appear to be successfully delivered to the SMTP server. Any ideas what settings to look at, what log entries to search for or how to compare the old web server with the new one will be highly appreciated.

  Read the article

• Windows Server 2003 (w/Exchange) move to new machine

  - by James Booker

  I have an ageing domain controller (the only one on a 10-pc network) which needs rebooting often. I have a Dell Poweredge 2850 server doing nothing, so I'd like to move the DC to that, but here's the catch - I don't have Win2k Server Std install media any more as it's been lost. I purchased "Easus Todo Backup Advanced Server" which claims to be able to recover to dissimilar metal, but it's not quite working (although I don't think it's the product's fault) I know the server and PERC RAID card are good because I installed Ubuntu on the logical drive (4 x 72GB disks RAID 5) no problems. I've booted frmo the Easus Todo backup CD (which is WinPE based) and recovered to the logical disk on the RAID (after installing driver inside the WinPE environment from a NAS drive) The problem is when I boot the server, I can get the OS selection menu, but any option results in a blank screen, with no errors. I figure this is probably because the driver wasn't installed on the old machine (which is IDE-based (i know, i know!) and doesn;t have a RAID controller) I've booted from the CD and copied the mraid35x.sys file to the c:\windows\system32\drivers folder on the recovered system, but it makes no difference. I made a boot.ini with rdisks 0-10 defined, and booting from each of these resulted in a file error (i.e. 'this isn't a real disk') - the only disk that gets any response (the blank screen) is multi(0)disk(0)rdisk(0)partition(1) which just gives me the blank black screen and no disk activity. Is there any way I can force the drvier to be installed on the source system (so i can do a full backup again), i've tried right-clicking the oemsetup.inf and clicking install, but it didn't actually do anything. I attempted to force it with the 'Add new hardware' wizard and forcing with the 'have disk' option but it still gave me no hardware to select. Also I've got an identical machine running WinXP which uses the PERC driver successfully (which was obviously done at install time) and the boot.ini settings are the same : multi(0)disk(0)rdisk(0)partition(1) Any ideas would be appreciated.

  Read the article

• CentOS server. What does it mean when the total used RAM does not equal the sum of RES?

  - by Michael Green

  I'm having a problem with a virtual hosted server running CentOS. In the past month a process (java based) that had been running fine started having problems getting memory when the JVM was started. One strange thing I've noticed is that when I start the process, the PID says it is using 470mb of RAM while the 'used' memory immediately drops by over a 1GB. If I run 'top', the total RES used across all processes falls short of the 'used' listed at the top by almost 700mb. The support person says this means I have a memory leak with my process. I don't know what to believe because I would expect a memory leak to simply waste the memory the process is allocated not to consume additional memory that doesn't show up using 'top'. I'm a developer and not a server guy so I'm appealing to the experts. To me, if the total RES memory doesn't add up to the total 'used' it indicates that something is wrong with my virtual server set-up. Would you also suspect a memory leaking java process in this case? If I use free before: total used free shared buffers cached Mem: 2097152 149264 1947888 0 0 0 -/+ buffers/cache: 149264 1947888 Swap: 0 0 0 free after: total used free shared buffers cached Mem: 2097152 1094116 1003036 0 0 0 -/+ buffers/cache: 1094116 1003036 Swap: 0 0 0 So it looks as though the process is using (or causing to be used) nearly 1GB of RAM. Since the process (based on top is only using 452mb, does that mean that the kernal is all of a sudden using an additional 500mb?

  Read the article

• troubleshooting postifx -> exchange connection issues

  - by Systemspoet

  I have three linux-based mail routers that run postfix and relay mail to our on-premise exchange server as well as to outlook.com, splitting the mail based on ldap atttributes. What I've observed sporadically since upgrading this spring from Exchange 2007 to 2010 is that all three of the mail relays will, for about 20 minutes, fail to connect to exchange. Postfix logs it as "lost connection with exchange.contosso.edu" ; this problem almost always occurs to all three mail relays at the same time, and lasts for slightly under 20 minutes. If I can catch it while it's occuring, and I manually do "telnet exchange.contosso.edu 25" from one mail relay and force a message through (helo, mail from, rcpt to, data, etc), then it clears that relay up. The exchange "server" is actually two machines with the HT role on them, load balanced via windows NLB. I've worked pretty hard to figure out what's happening from the postfix side and I can't see any evidence of any misbehavior. My question is, how do I attack the problem from the exchange side? Is there a connection log, or a debug setting, or something I can do to log all of the inbound connections and tell me what's causing exchange to drop them?

  Read the article

• SSH & SFTP: Should I assign one port to each user to facilitate bandwidth monitoring?

  - by BertS

  There is no easy way to track real-time per-user bandwidth usage for SSH and SFTP. I think assigning one port to each user may help. Idea of implementation Use case Bob, with UID 1001, shall connect on port 31001. Alice, with UID 1002, shall connect on port 31002. John, with UID 1003, shall connect on port 31003. (I do not want to lauch several sshd instances as proposed in question 247291.) 1. Setup for SFTP: In /etc/ssh/sshd_config: Port 31001 Port 31002 Port 31003 Subsystem sftp /usr/bin/sftp-wrapper.sh The file sftp-wrapper.sh starts the sftp server only if the port is the correct one: #!/bin/sh mandatory_port=3`id -u` current_port=`echo $SSH_CONNECTION | awk '{print $4}'` if [ $mandatory_port -eq $current_port ] then exec /usr/lib/openssh/sftp-server fi 2. Additional setup for SSH: A few lines in /etc/profile prevents the user from connecting on the wrong port: if [ -n "$SSH_CONNECTION" ] then mandatory_port=3`id -u` current_port=`echo $SSH_CONNECTION | awk '{print $4}'` if [ $mandatory_port -ne $current_port ] then echo "Please connect on port $mandatory_port." exit 1 fi fi Benefits Now it should be easy to monitor per-user bandwidth usage. A Rrdtool-based application could produce charts like this: I know this won't be a perfect calculation of the bandwidth usage: for example, if somebody launches a bruteforce attack on port 31001, there will be a lot of traffic on this port although not from Bob. But this is not a problem to me: I do not need an exact computation of per-user bandwidth usage, but an indicator that is approximately correct in standard situations. Questions Is the idea of assigning one port for each user is a good one? Is the proposed setup an reliable one? If I have to open dozens of ports for many users, should I expect a performance drawback? Do you know a rrdtool-based application which could make the chart above?

  Read the article

• Which free RDBMS is best for small in-house development?

  - by Nic Waller

  I am the sole sysadmin for a small firm of about 50 people, and I have been asked to develop an in-house application for tracking job completion and providing reports based on that data. I'm planning on building it as a web application. I have roughly equal experience developing for MySQL, PostgreSQL, and MSSQL. We are primarily a Windows-based shop, but I'm fairly comfortable with both Windows and Linux system administration. These are my two biggest concerns: Ease of managability. I don't expect to be maintaining this database forever. For the sake of the person that eventually has to take over for me, which database has the lowest barrier to entry? Data integrity. This means transaction-safe, robust storage, and easy backup/recovery. Even better if the database can be easily replicated. There is not a lot of budget for this project, so I am restricted to working with one of the free database systems mentioned above. What would you choose?

  Read the article

• How much free memory should I have on my webserver?

  - by neanderslob

  I have a webserver that's currently hosting two Wordpress sites and some java-based collaboration software. The server has 2G of memory and is currently using about 1.8G of the available memory. Right now what's on here is pretty much a pilot project that's getting negligible traffic so I think it's pretty clear that I'll be needing more memory. I was wondering, if I was to release it, how I might anticipate my memory needs based on the traffic it gets. I've poked around on Google and what I've found has been a bit tenuous. Is there a good heuristic that one should use when calculating memory demands as a function of the base (no traffic) load on the server? For reference, the output of free -m can be seen below: total used free shared buffers cached Mem: 2048 1832 215 0 0 0 -/+ buffers/cache: 1832 215 Swap: 0 0 0 To me this looks like actual memory used and isn't an illusion due to caching or anything else. I figure the demands of my collaboration software will have to be experimentally tested so here's free -m without that software running: total used free shared buffers cached Mem: 2048 1109 938 0 0 0 -/+ buffers/cache: 1109 938 Swap: 0 0 0 My plan B to figure this out is to add a bunch of swap space to the server, give it some traffic and adjust according the the amount that swap gets used. I was just wondering if anyone had a good rule of thumb to estimate how much memory I should plan on in advance...or if what I'm thinking is nuts. Many thanks in advance (I'm really quite new to this).

  Read the article

• PHP Web Server Solution (Apache/IIS)

  - by njk

  I apologize if this is too broad or belongs on Super User (please vote to move if it does). I'm in the process of creating requirements for an internal PHP web server to submit to our architecture team and would like to get some insight whether to use a Windows or *nix platform and what applications would be required. The server will host a small PHP application that will be connecting to SQL Server. The application will need to send mail. We would also like to incorporate a FTP server to allow files to be dropped in. From what I've read regarding a Windows platform using IIS, it seems as though IIS would only be advantageous if using a .NET or ASP application. Does IIS have mail functionality? Or how is mail traditionally configured (esp. on *nix)? Also, does IIS have directory configuration functionality like Apache does with .htaccess? For a Windows based solution; IIS (comes with FTP) Apache (has mod_ftp module) For a *nix based solution; Apache

  Read the article

< Previous Page | 254 255 256 257 258 259 260 261 262 263 264 265  | Next Page >