UrkoM's questions

I am looking at buying a cost-effective machine for using openAttic, which is simply Ubuntu 14.04 64bit with ZFS.

The server I am looking at gives me 8 bays of 3.5", where I plan to put SAS 7.2k enterprise grade HDDs, probably 3Tb or 4Tb. I'm aiming for 18Tb to 24Tb of usable space, with 2 HDDs for redundancy. I'll get 32Gb of ECC RAM at least, but I will look at cost of 64Gb.

I am not experienced enough with ZFS, but initially my plan was to use a small boot and system partition, mirrored across all the drives, using ext4. Then using the remaining space for ZFS.

The server has an M.2 slot: Should I get an M.2 SSD there to use as the boot/system drive? OpenATTIC needs very little for the system partition, so it seems like a waste to get a premium SSD for that, when RAM and the SAS drives will be doing most of the work and will be the bottleneck.

I have read that ZFS likes to get direct access to the disks, so I wonder: Can ZFS can work well when you configure it to not use the whole disk? Or should I get the SSD and let ZFS take all the SAS disks?

If money is not a limitation, of course I get the SSD, but I am looking for "best value for money". Thanks!

I'm trying to install Cygwin with SSHd on a Windows Server 2008 R2 domain controller. I have installed Cygwin and SSHd several times on other machines, with no issues. Being a domain controller, the cyg_server user is part of the domain. I have enabled SeTcbPrivilege on the Group Policy for Domain Controllers for DOMAIN\cyg_server, but it's somehow not applying.

The output of gpresult /v is:

        GPO: Default Domain Controllers Policy
            Policy:            TcbPrivilege
            Computer Setting:  Administrators
                               DOMAIN\cyg_server
                               DOMAIN\Domain Admins

Running RSoP.msc is consistent with gpresult, and also shows that those groups and the cyg_server user should have TcbPrivilete.

But the output of whoami /priv shows SeTcbPrivilege "Disabled":

PRIVILEGES INFORMATION
----------------------

Privilege Name                  Description                   State
=============================== ======================================================== ========
<...>
SeTcbPrivilege                  Act as part of the operating system
               Disabled
<...>

I can start the Cygwin SSHd service, but I can only log on as cyg_server. When I try to log on as Administrator, I see this:

urkom@workstation:~$ ssh Administrator@domaincontroller
Administrator@domaincontroller's password: 
Last login: Tue May  7 13:26:29 2013 from 172.1.10.22
/bin/bash: Operation not permitted
Connection to domaincontroller closed.

For reference, here is the relevant line of /etc/passwd:

Administrator:unused:500:513:Administrator,U-DOMAIN\Administrator,S-1-5-21-3835976426-429400520-196227251-500:/home/Administrator:/bin/bash

I'm stuck, so any help would be welcome. Thank you.

I am trying to set up an HTTP reverse proxy to an internal HTTPS server. As a sidenote, yes, I know I am throwing all security away. The original HTTPS server is not sensitive in nature for us, and the product that runs it does not allow turning off HTTPS or reconfiguring the embedded webserver in any way.

I have tried with Nginx, but most people out there seem to be using Apache, so that's what I'm trying now.

This is my current virtual host configuration:

<VirtualHost 0.0.0.0:10443>
    ServerName server.domain.com

    SSLProxyEngine on
    #UnknownSSLDirectives
    #SSLProxyMachineCertificateFile /etc/apache2/selfsignedcert.pem
    SSLProxyCACertificateFile /etc/apache2/selfsignedcert.pem

    ProxyRequests Off
    ProxyPass / https://internalserver.internaldomain.com:2941/
    ProxyPassReverse / https://internalserver.internaldomain.com:2941/

    <Proxy>
        Order Deny,Allow
        Allow from all
    </Proxy>

    RequestHeader unset Authorization

    ErrorLog /var/log/apache2/internalserver-error.log
    CustomLog /var/log/apache2/internalserver-access.log common

</VirtualHost>

When I try to open http://server.domain.com:10443/ I get the error "401 Unauthorized".

In other ServerFault questions I saw references to UnknownSSLDirectives, but Apache complains that the option doesn't exist. And to using SSLProxyMachineCertificateFile instead of SSLProxyCACertificateFile, but Apache complains that the SSL setup is incomplete in that case.

I am quite stuck. How can I debug this or make some progress? Thank you!

I'm trying to rename our Active Directory domain, following the instructions here: http://social.technet.microsoft.com/wiki/contents/articles/1347.renaming-a-windows-server-2008-active-directory-domain-dsforum2wiki.aspx (as well as several others that I've looked for when I've run into problems)

I download the forest information with rendom /list Then I do a search and replace to get the new domain name configured. rendom /showforest shows me a new forest tree that looks good. When I run "rendom /upload", I get this error:

C:\donrem>rendom /upload
Search to find Configuration container failed: The system cannot find the file specified. :2

Checking with adsiedit.msc, I can see that the Configuration container was found, and the msDS-UpdateScript property gets updated with some code, so obviously the rendom command is able to find it and change it.

I have searched, but found no reference to this error, so I suspect my Active Directory is messed up. Does anyone have suggestions to move forward? Thanks!

We are running Vyatta Core 6.2, based on Debian Squeeze, on a Dell R710 server.

I came across these instructions to install the command line Dell Management utilities: http://linux.dell.com/repo/community/deb/latest/

So I installed srvadmin-all, and it all seemed to work fine. However, omconfig, omreport and other Dell tools are not available.

Does anyone have any suggestions?

I am trying to setup Wordpress Multisite, using subdirectories, with Nginx, php5-fpm, APC, and Batcache. As many other people, I am getting stuck in the rewrite rules for permalinks.

I have followed these two guides, which seem to be as official as you can get: http://evansolomon.me/notes/faster-wordpress-multisite-nginx-batcache/ http://codex.wordpress.org/Nginx#WordPress_Multisite_Subdirectory_rules

It is partially working:

• http://blog.ssis.edu.vn works.
• http://blog.ssis.edu.vn/umasse/ works.

But other permalinks, like these two to a post or to a static page, don't work:

• http://blog.ssis.edu.vn/umasse/2008/12/12/hello-world-2/
• http://blog.ssis.edu.vn/umasse/sample-page/

They either take you to a 404 error, or to some other blog!

Here is my configuration:

server {
    listen       80 default_server;
    server_name  blog.ssis.edu.vn;
    root         /var/www;

    access_log   /var/log/nginx/blog-access.log;
    error_log    /var/log/nginx/blog-error.log;

    location / {
        index index.php;
        try_files $uri $uri/ /index.php?$args;

    }

    # Add trailing slash to */wp-admin requests.
    rewrite /wp-admin$ $scheme://$host$uri/ permanent;

    # Add trailing slash to */username requests
    rewrite ^/[_0-9a-zA-Z-]+$ $scheme://$host$uri/ permanent;

    # Directives to send expires headers and turn off 404 error logging.
    location ~* \.(js|css|png|jpg|jpeg|gif|ico)$ {
        expires 24h;
        log_not_found off;
    }

    # this prevents hidden files (beginning with a period) from being served
      location ~ /\.          { access_log off; log_not_found off; deny all; }

    # Pass uploaded files to wp-includes/ms-files.php.
    rewrite /files/$ /index.php last;

    if ($uri !~ wp-content/plugins) {
        rewrite /files/(.+)$ /wp-includes/ms-files.php?file=$1 last;
    }

    # Rewrite multisite '.../wp-.*' and '.../*.php'.
    if (!-e $request_filename) {

        rewrite ^/[_0-9a-zA-Z-]+(/wp-.*) $1 last;
        rewrite ^/[_0-9a-zA-Z-]+.*(/wp-admin/.*\.php)$ $1 last;
        rewrite ^/[_0-9a-zA-Z-]+(/.*\.php)$ $1 last;

    }

    location ~ \.php$ {
    # Forbid PHP on upload dirs
        if ($uri ~ "uploads") {
            return 403;
        }

        client_max_body_size 25M;
        try_files      $uri =404;
        fastcgi_pass   unix:/var/run/php5-fpm.sock;
        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        include        /etc/nginx/fastcgi_params;
    }
}

Any ideas are welcome! Have I done something wrong? I have disabled Batcache to see if it makes any difference, but still no go.

We run VMWare vSphere 4.1, and VMWare Data Recovery 1.2. We have a weekly window with no backups happening, and due to some instabilities, we would like to try scheduling an automatic weekly reboot of the VMWare Data Recovery appliance.

More specific details: - VMWare Data Recovery 1.2 seems to be based on CentOS 5.2. - We use NFS for data storage. The appliance sees this as local storage, but the drive is actually stored in a different building. Seems to work great, and so far has been significantly faster and more stable than CIFS (which we used before).

I have tried scheduling the reboot using /etc/cron.d within the VDR appliance itself:

/etc/cron.d/sunday_reboot:

45 1     * * sun   /usr/local/bin/custom_reboot.sh >> /var/log/reboot.log

/usr/local/bin/custom_reboot.sh:

#!/bin/bash
/bin/echo "==================================="
/bin/date
/bin/echo "Rebooting server now."
/usr/bin/reboot

I also restarted crond, /etc/init.d/crond restart However, /var/log/reboot.log stays empty, and uptime shows that no reboot ever happened.

What am I missing?

I am running Squid 3 on Ubuntu 10.04, with SARG for reports. It's mostly working quite well, but I'm running into problems with the server becoming totally full with the SARG reports.

I created this script, that tries to get rid of anything older than 45 days in the reports folder, but I think it caused some problems, because SARG hasn't run properly since then.

#!/bin/bash
find /var/www/squid-reports/* -type f -mtime +45 -exec rm -f {} \;
find /var/www/squid-reports/* -type d -mtime +45 -exec rmdir {} \;

What would be the recommended way to take care of this? Thank you!

I am running Squid 2.7 on Ubuntu 10.04 64bits. I had the problem of Squid running out of file descriptors, with the following error showing in /var/log/squid/cache.log:

WARNING! Your cache is running out of filedescriptors

I checked with:

squidclient mgr:info | grep 'file descri'

and it showed that I had only 1024 file descriptors available.

I changed /etc/security/limits.conf, adding this at the end:

* soft nofile 32768
* hard nofile 32768
proxy           soft    nofile          32768
proxy           hard    nofile          32768

Added this to /etc/squid/squid.conf:

max_filedescriptors 32768

Also changed /etc/default/squid:

SQUID_MAXFD=32768

Nothing was working out. In the end I edited /etc/init.d/squid to add "ulimit -n 32768":

#!/bin/sh -e
# upstart-job
#
# Symlink target for initscripts that have been converted to Upstart.

set -e
ulimit -n 32768
<... snipped  ...>

That worked! :)

I had to do all this under the stress of a live, production Squid server being incredibly slow, so I am sure that this is NOT the right way to do it.

But what is the right way to do it?

We have a Squid 2.6 server running on Ubuntu 8.04. We have an SNMP monitoring software (Zabbix) that gives us almost real time graphs of our internet connection.

I have tried to use squidview to see who is abusing the network, but the "tally" mode always starts checking the log from the beginning of the logfile.

If I understood correctly, I can move to a later line in the log, and start "tally" mode from there, but it's not working. It starts from the top anyway.

Any ideas? Any other options for finding bandwidth hogs in "real time"? (it's never really real time, but close to it is enough)

Thanks!