totalnetsolutions.net

I’ve been fighting K9Mail for weeks now, trying to get it to sync with MailStreet (http://www.mailstreet.com who hosts “exchange.ms”) hosted Exchange. If you’ve already followed the instructions at the K9Mail Wiki with no success, read on.

Thanks to the k9mail wiki on debugging connection issues and the fact that I already had the Android SDK installed, I was able to solve the 2 related errors I was getting. I would either get an “HTTP 404 not found” or an “HTTP 501 Not Implemented” depending on the settings I chose. With no additional settings other than suggested in the Wiki, I’d get a “501 not implemented”. If I tried to set a mailbox path, or a WebDAV path, I’d get the HTTP 404 Not Found.

In the debugging log, I saw that the system was calling “http://mail.$domain.exchange.ms/”$webDAVpath/Inbox – if I set it to a full URL, the full URL was getting appended. When I attempted to hit those same paths in a full browser, I’d always get an HTTP 404. So, digging in my history in Firefox, I found the following (cleaned) path:
http://mail.$domain.exchange.ms/exchange/$emailaddress/
In this case $emailaddress was my Exchange mail address with the “@” stripped out. Appending “Inbox” to the end of this path resulted in a valid load of my OWA inbox.

Plugging then: /exchange/$emailaddress/ into the WebDAV box in K9Mail, and my email immediately loaded up.

Now I have Android syncing my calendars and contacts, and k9mail is handling my massive inbox!

The past week has given me major troubles.  I was tasked with performing a restore of a large database from our offsite storage.  Upon getting the tapes back I found that their indexes were no longer available and I would need to read them in from the tapes…there were only 107 tapes.  Not knowing the software well enough to accomplish this quickly I contacted support, where things began to get more…”interesting”.

After four hours on the phone I was able to determine the two tapes that would be needed to recover the 79Gb database file and started reading in the specific saveset that was needed.  Two hours later I was able to start a restore, which failed.  2Gb of the restore file was missing.  After another two hours on the phone with support I was told “Let’s reposition the tape.  It could take a while, on newer technology I’ve seen it take an hour, on LTO1 and LTO2 drives I’ve seen it take 8 hours.”  You guessed it, I have LTO2 drives.  Fortunately I have a multitude of drives to reposition the tapes with so it won’t impact backups, unfortunately I have a time limit on the restore that’s fast approaching.

So what do you do when you backup your file systems?  Do you simply believe that the software you backup with validates your tapes or do you test them regularly?  Are you satisfied with seeing an email at the end of a backup routine stating “SUCCESS”?  Then answer is simply NO.  Your backups are only as good as your ability to restore from them. Keeping that in mind and all the different technologies and services available what do you choose?

For us the answer is simple.  We require low cost, reliable, offsite secure data storage as do most companies nowadays.  TAPE.  We’ve looked into collocated services and replicated SANs with virtual tape backup but the cost far exceeds it’s benefits.  Tape technology has been proven over and over for decades.  There is no cost effective replacement for a good old fashioned tape, even taking into consideration the troubles it can give you.  Our entire datacenter can be put onto 6 tapes costing $25 each.  4.8TB for $150.

Any good backup initiative should be followed up with an equally adequate restore plan.  So next time you recommend a backup solution plan a regular restore plan to test because there’s nothing worse than spending an entire week restoring one file.

We’ve had a few customers and Open users posting about problems with machine accounts trying to access Samba shares and getting denied with:
smbd/sesssetup.c:reply_spnego_kerberos(439) Username DOM\COMPUTER1$ is invalid on this system
The “$” at the end of the account name means it’s a computer account, not a user. We’re seeing this for Citrix MetaFrame application servers on shared storage, startup scripts not stored on a DC, and several other cases.

On a Samba server joined to AD with winbind, this is easy to deal with because Samba’s winbind can treat the computer accounts just like user accounts, and assign them access to the unix filesystem with whatever backend has been configured. When a Samba server is joined with Likewise, however, the machine accounts are not visible, and the “username is invalid” message comes up.

Fortunately, Samba gives us a method to handle this, in form of the “username map” directive in /etc/samba/smb.conf.  There are two ways to use this, the first is with the username map file.
In smb.conf, to simply add:
[global ]
username map = /etc/samba/smbusers
then create a file named /etc/samba/smbusers and populate it with localuser=aduser pairs, like:
COMPUTER1$ = compacct
COMPUTER2$ = compacct
CITRIXFARM1$ = citrxact
and so on. Lastly, you’ll have to add the local accounts from the pairs above:
useradd -c "Account for AD Computers to use Samba" compacct -G users -u 998
useradd -c "Account for AD Citrix Servers to use Samba" citrxact -G users -u 999
Then, whenever one of the AD computers in the list attempts to access the Samba share, it’ll be mapped to the local account.

The problem with this is when you have a lot of servers, like a Citrix MetaFrame farm, or a Windows Server 2008 R2 Remote Desktop Services farm, that may be changing frequently, because managing that file could get hard. In this case there is the username map script directive, which is added to smb.conf as:
[global ]
username map script = /usr/lib/samba/auth/machine-acct-map.pl
Then download this script and save it in /usr/lib/samba/auth/ and make it executable (chmod +x /usr/lib/samba/auth/machine-acct-map.pl). Then run:
useradd -c "Account for AD Computers to use Samba" compacct -G users -u 998
Now, all computers which access the share will be remapped to the “compacct” user, and you won’t have to manage a file for every time the server farm changes.

Get the file here.

More and more of my customers are (rightly) installing 64-bit versions of Windows for critical systems like Domain Controllers, File Servers, and Database Servers.  The increased memory access for user-mode programs (and increased file cache size for file servers) is a huge help for heavily used systems.

But there are are still a lot of tools only written for 32-bit systems.  That is to say, MMC consoles and VBScripts that just act… funny on 64-bit servers.  So, here’s some errors, and how to quickly fix them.

For VBScripts, you’ll often just get an error similar to:
scriptname.vbs(48, 1) Microsoft VBScript runtime error:
ActiveX component can't create object:
It doesn’t matter what the object is, and if you register the supporting DLL or reinstall the application that provides the function, it still won’t work. The fix? c:\windows\syswow64\cscript scriptname.vbs or c:\windows\syswow64\wscript scriptname.vbs, depending on if you want it run in a console (cscript) or popup windows (wscript). I personally write everything for cscript, cause I can redirect the output to a log file. This trick I found here, and reminded me to write this up with my next fix.

For MMC consoles, what often happens is you just don’t see the tab you’re looking for, or you can’t even find the console to add the snap-in to the MMC. No error messages, and nothing shows up that you’re looking for. Luckily, this is also an easy fix. Click the Start button, then “Run…” then type in “mmc /32″ or “mmc -32″ in the box and click “OK”. You’ll now be presented with an empty MMC, but you can now add the snap-ins you want, and the 32-bit programs (such as the “Additional Account Information” from acctinfo.dll from the Windows Resource Kit Tools) will have their tabs show up properly.

I ran into a problem today where I couldn’t remember the native packet capture tool for Solaris and couldn’t install tcpdump, so i thought I’d put down as many as many native packet capture commands as I knew, by OS, in a single place.  I’ll update this as I find more, since there’s hundreds of Operating systems out there.

• AIX: iptrace: /usr/sbin/iptrace [ -a ] [ -b ][ -e ] [ -u ] [ -PProtocol_list ] [ -iInterface ] [ -pPort_list ] [ -sHost [ -b ] ] [ -dHost ] [ -L Log_size ] [ -B ] [ -T ] [ -S snap_length] LogFile
• FreeBSD: tcpdump (I think): tcpdump [ -adeflnNOpqRStuvxX ] [ -c count ] [ -C file_size ] [ -F file ] [ -i interface ] [ -m module ] [ -r file ] [ -s snaplen ] [ -T type ] [ -w file ] [ -E algo:secret ] [ expression ]
• HP-UX: nettl: nettl requires a daemon start, and other setup: /usr/sbin/nettl -traceon kind… -entity subsystem… [-card dev_name...] [-file tracename] [-m bytes] [-size portsize] [-tracemax maxsize] [-n num_files] [-mem init_mem [max_mem]] [-bind cpu_id] [-timer timer_value]
• Linux 2.4 and higher:
  • tcpdump (some distros): tcpdump [ -AdDefKlLnNOpqRStuUvxX ] [ -c count ] [ -C file_size ] [ -G rotate_seconds ] [ -F file ] [ -i interface ] [ -m module ] [ -M secret ] [ -r file ] [ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ] [ -E spi@ipaddr algo:secret,... ] [ -y datalinktype ] [ -z postrotate-command ] [ -Z user ] [ expression ]
  • wireshark (some distros, used to be called “ethereal”): GUI-config, no command-line, use tethereal (now tshark) for that
  • tshark: tshark [ -a <capture autostop condition> ] … [ -b <capture ring buffer option>] … [ -B <capture buffer size (Win32 only)> ]  [ -c <capture packet count> ] [ -C <configuration profile> ] [ -d <layer type>==<selector>,<decode-as protocol> ] [ -D ] [ -e <field> ] [ -E <field print option> ] [ -f <capture filter> ] [ -F <file format> ] [ -h ] [ -i <capture interface>|- ] [ -l ] [ -L ] [ -n ] [ -N <name resolving flags> ] [ -o <preference setting> ] … [ -p ] [ -q ] [ -r <infile> ] [ -R <read (display) filter> ] [ -s <capture snaplen> ] [ -S ] [ -t ad|a|r|d|e ] [ -T pdml|psml|ps|text|fields ] [ -v ] [ -V ] [ -w <outfile>|- ] [ -x ] [ -X <eXtension option>] [ -y <capture link type> ] [ -z <statistics> ] [ <capture filter> ]
• Mac OSX: tcpdump (among others): tcpdump [ -adeflnNOpqRStuvxX ] [ -c count ] [ -C file_size ] [ -F file ] [ -i interface ] [ -m module ] [ -r file ] [ -s snaplen ] [ -T type ] [ -w file ] [ -E algo:secret ] [ expression ]
• Solaris: snoop: snoop [ -aPDSvVNC ] [ -d device ] [ -s snaplen ] [ -c maxcount ] [ -i filename ] [ -o filename ] [ -n filename ] [ -t [ r | a | d ] ] [ -p first [ , last ] ] [ -x offset [ , length ] ] [ expression ]
• Windows 2000, XP, 2003, Vista, 2008 and beyond:
  • netmon (not installed by default): GUI config, filter creation info here
  • wireshark (available by download): GUI-config, no command-line

Any others anyone wants added (or corrected), just comment or email and I’ll update this.
(Edit 7/29/08 – change tcpdump link)
(Edit 10/13/08 – add tshark info, thanks Jefferson!, and wireshark on Windows)
(Edit 12/27/09 – update IBM iptrace man page link)