I have a PowerEdge R815 with quad Opteron 6272 and a faulty DIMM slot at A2. The system still boots with no DIMM installed there, but with warnings of an invalid memory configuration. I can silence the warning, but what kind of performance penalty can I expect?
I have an internal 68-pin SCSI cable with space for 5 devices. The cable is damaged between the 3rd and 4th space and prevents the drive in the 1st space (the only drive) from functioning. In most cases, I would just replace the cable. But the connector to the motherboard is proprietary and near impossible to find a replacement for.
Would it be feasible to place a terminator in the 2nd space and have it function? The cable has a terminator at the end, but it's soldered in place. Alternatively, could I just snip off the cable right before the break and put the terminator there?
I have two files of interest in /var/www/html (in CentOS): index1.html, and index2.html.
index1.html was downloaded from a website and chowned to root and chmoded 0644. index2.html was created by root, and had the contents of index1.html copied into it. They have identical contents, and identical permissions. Apache will load index2.html, but will return a 403 Forbidden error for index1.html. If I swap the filenames, the permissions problem follows with the rename. What's going on?
[root@localhost html]# ls -al
total 52
drwxr-xr-x. 6 root root 4096 Jul 8 13:32 .
drwxr-xr-x. 6 root root 4096 Jul 8 12:59 ..
drw-r--r--. 2 root root 4096 Jun 26 12:14 css
-rw-r--r--. 1 root root 1558 Jul 8 11:42 dashboard.css
drw-r--r--. 2 root root 4096 Jun 26 12:14 fonts
-rw-r--r--. 1 root root 8744 Jul 8 13:12 index1.html
-rw-r--r--. 1 root root 8744 Jul 8 11:42 index2.html
drw-r--r--. 2 root root 4096 Jul 8 13:32 js
drw-r--r--. 4 root root 4096 Jun 21 18:39 PHP_Site
[root@localhost html]#
The rest of the files were downloaded and chowned/chmodded, and they also all return 403 errors. index2.html is the only file apache will load.
If I 'su apache' and cat the files, it can read all of them.
I have dial-up server and client software that I want to be able to test and script. Unfortunately, I don't own a landline. Much less, multiple lines that I can use to test concurrent connections.
What I do have, is a handful of modems and a computer to plug them into. Is there any way that I could simulate a phone line in such a way? As in, actually be able to plug in a landline telephone in, get a dial tone, be able to dial a number, and route it to my software on the server?
I appologize if this is not the appropriate forum for this question. I'm afraid I have no idea where to start with this, or if what I'm attempting is entirely half-baked.
Is it possible to daisy chain a shared folder in Windows? As in:
Machine A only has permission to talk to B, and A is sharing a folder to B. C wants a file in A's shared directory. Can B re-share the directory from A and serve it to C?
A satellite connection generally has a RTT around 500ms. Connections generally suffer sub-optimal transfer speeds, in spite of large amounts of bandwidth because TCP acknowledgements take too long to arrive.
My understanding is that a good way to address this problem with TCP connections is to set the TCP Window size to the connection speed (in bits) multiplied by RTT (in seconds). So a 1mbps connection over satellite should have a window size of 512kb.
What pitfalls are involve in this? Are there any other similar tweaks that should be made to optimize for satellite connections? I understand that many modern operating systems will modify the window size automatically, but will they be aggressive enough to make window sizes large enough to work for satellite communication?
As an aside, I'm going to assume that a large window size is not desirable on networks that frequently drop packets, as the retransmission will be at the window size, and you may dedicate much of your bandwidth to retransmission overhead.
Thank you, I'm still learning a great deal about networking and appreciate your input.
I'm setting up a server to operate as a tor relay and nothing else. I setup iptables to only allow talk on port 9001 and it worked fine, but there was an issue, the clock needs to be properly set and maintained for the relay to work properly, so I needed ntpd setup and running, but for some reason I can't get iptables to work as I want it. I'm trying to have it allow only tor and ntpd to talk over the network, but when I set it up to allow port 123 using udp, suddenly it ignores my -A OUTPUT ! -s 127.0.0.1 -j DROP and allows everything through. How should I go about this? Please excuse my ignorance, I've brand new to iptables.
I've gone through a number of permutations, but here are my rules as they stand now:
-A INPUT -p udp --sport 123 --dport 123 -j ACCEPT
-A OUTPUT -p udp --sport 123 --dport 123 -j ACCEPT
-A INPUT -p tcp -m tcp --sport 9001 -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 9001 -j ACCEPT
-A INPUT ! -s 127.0.0.1 -j DROP
-A OUTPUT ! -s 127.0.0.1 -j DROP