anomalous territory


Isolate backups to a remote Linux/BSD/OSX server via “pull” over SSH

by admin on Aug.13, 2009, under backup, linux, software, ssh

My primary motivation for doing this was security. I’ve been reading some forensic logs lately and a great way to shoot yourself is if your critical servers perform “push” backups to elsewhere.

A typical example of this would be if I have a database server, and on this happy database server I have a crontab entry that creates a nightly snapshot of all the databases and then runs a little script to scp them all over to a backup server somewhere.

On first impressions, this sounds fine. You’ve got a production database server. You’ve got a remote backup server. You’ve got nightly jobs that run. Awesome! Well protected!

*bzzzzzz* You’re protected from innocent hardware failure, sure, but what happens when someone manages to compromise your database server and login? Regardless of their motivation, if they can read your nightly backup script, you are unbelievably screwed. They’re now not only pwning your production database server, but they have access to your remote backup server too and any historical data might as well be kissed good bye.

I wanted to be defensive and consider this scenario a “when” and not an “if”. My solution is nothing new, but it’s something I don’t see suggested much: Make the backup server PULL from the production database server using private/public ssh keys . For example: backup server has crontab entries that tell it to login to your production systems and copy the same databases you were previously telling the production servers to worry about. Also you can limit any commands the backup user’s login is allowed to issue on the production side. The backup server should also be behind a firewall, on a private network, isolated away from the outside world except for outbound connections in the direction of the production server.

Now not only do you have a happy database, you have an isolated backup server with absolutely no references to where or how the backups are stored.

An added benefit is that if you need to deploy any new production servers, all of their backup requirements can be centralized instead of adding multiple crontab entries to multiple new server at each deployment state. (It’s also a pain if your backup strategy changes greatly as you’d have to maintain many distributed references to your backup infrastructure.)

Obviously this is primarily for smaller scale systems. If you’re running Oracle 10g and have the infrastructure to support distributed RAID arrays full of redundant backups with offline tape libraries, well you’re probably here by accident then. However, if you’re running PostgreSQL or MySQL on a VPS somewhere, I hope this has been thought provoking at the least.

(Later I’ll post some actual How To code/commands to implement this.)

1 Comment more...

Extremely Useful Free Windows Software

by volve on Jul.07, 2007, under software

3 pieces of software that I’ve never really seen mentioned anywhere that I simply can not live without:


Free image browser/organizer with every feature of ACDSee and Adobe Bridge and many more. Just look at the operating systems it runs on: Windows, MacOS X, Linux x86, Linux ppc, FreeBSD x86, OpenBSD x86, NetBSD x86, Solaris sparc, Solaris x86, Irix mips, HP-UX, AIX – that’s dedication right there. I really do use this tool every single day, it’s simply that amazing. The Windows Shell extension alone is wonderful – instant thumbnail on the right-click menu of any supported file type. I don’t know why more people aren’t aware of this tool.


This brilliant tool lets you find (and automatically delete, if you wish) duplicate files in 2 or more locations on your system. You can do a full byte-for-byte compare, or simply rely on the filenames. You can also designate “pools” so only files listed in say Pool 2 will have the duplicate files deleted, should you wish to maintain any copies found in Pool 1 for example. A truly invaluable tool that’s saved me many, many hours of time and vast quantities of disk space!

RED (Remove Empty Directories)

This tool is fairly similar in function to CloneSpy above, except it works on empty directories and/or empty files. You specify a path for it to scan and it quickly goes through and presents a color-coordinated set of empty directories which it will happily remove with a confirmation click. It’s also smart enough to remove parent directories if after deleting empty sub-directories, said parent is also now entirely empty.

Leave a Comment more...

iTunes Media Wrangling with Smart Playlists

by volve on Nov.29, 2006, under media storage, software

UPDATE: It appears, at least in iTunes 7.0.2 that isntead of creating some big, cumbersome playlist with lots of “is not” entries as mentioned in the first link below, you can simple do “Playlist, is, Music” or “Playlist, is, TV Shows” – yay!

iTunes has some awesome features, but some odd deficiencies.

One such is the inability to build a Smart Playlist that contains ONLY music, or ONLY TV shows for example.

Although a handy solution is within your grasp. A useful feature of these Smart Playlists is to read OTHER playlists, so basically you create a big ol’ big list that excludes -for example- all TV, Movies, Podcasts, etc. then include that in your Music-only playlists going forward.

A handy guide explaining the aformentioned music-only base playlist:

Some other excellent iTunes wrangling tips of all varieties:

Good luck and god speed!

Leave a Comment more...

scrybe organiser

by volve on Oct.22, 2006, under software, ui, web

This looks fairly impressive. At times it appears as though they’re using Flash or Flex, but at others it’s hard to tell. In any case, it should be fun to see. I’m particularly impressed with the couple of different printing options mentioned, and the smooth integration of timezones. I’m not so enamored with the Offline support as I think it’ll have many limitations, unless they’re definitely using Flex… hmmm

Teasing details and a beta email signup available at: Scrybe site

Leave a Comment more...

Media Recovery

by volve on Apr.22, 2006, under linux, media storage, software

The bane of having an awesome media server, regardless of whether it houses audio, video, photos or all-of-the-above is that you have to rely on physical devices somewhere to store the data…

Having recently had yet another hard drive decide to begin spewing bad sectors, I went on the hunt for recovery information for the overly complicated LVM2 system I was running. The immediate prospect of having to mirror the entire ~2TB filesystem before being able to run a repair made my head hurt. After acquiring a replacement disk for the 1 in poor health, I was tempted to try the standard Linux command ‘dd’ with some ignore errors and pad blocks options, but then I happend to stumble upon TestDisk which sounded extremely versatile and useful. However, what I was most impressed with was their extremely informative MediaWiki-based site and in particular, the Damaged Hard Disk area with references to two different versions of ‘dd rescue’ tools, in particular Antonio Diaz’s ddrescue utility. Essentially after you tell it the bad disk, and somewhere (file or other disk) to write the data, it’s fully automated. If you make sure to use the logfile feature, it can even resume and pick-up where it left off if your recovery process is interrupted for any reason.

If you’ve had hard disk/CD/DVD failures for whatever reason, I strongly suggest looking at the TestDisk page as it runs across >6 operating systems and supports >17 different filesystems derivations – oh and their site is very helpful. Have at it!

Leave a Comment more...

media server software rant update (mini review)

by volve on Feb.06, 2006, under articles, media storage, movies, software, ui

It appears that the sorry state of UIs in media server software doesn’t extend to the Mac platform. I’ve been surfing around reading a few obscure articles this week and although the software isn’t very mature, I’ve been quite impressed with several Mac projects. Namely: MediaCentral, CenterStage, iTheatre, and CoverFlow. The best part is that unlike some of the Windows appliations, these three for the Mac are free! (Try saying that ten times fast.)

Although MediaCentral is quite text-based for navigation, its presentation is definitely a lot sharper and more refined than any of the others. CenterStage is intersting and has a lot of potential, but better be careful not to ‘over utilize’ available space. It’s definitely the most mature of the projects. My main gripe is that if I’m browsing a bunch of movie covers (which BackStage – the CenterStage backend component sucsessfully downloaded for me), why do I need a text title underneath them? I don’t; it simply wastes space. Also the cover browsing section seems awfully small, but as I didn’t poke too deeply, one might be able to turn off the preview area to the right (that would be handy). iTheatre is at RC1 currently and has quite a few pieces of missing functionality, but could be nice although is heavily text-based like MediaCentral. CoverFlow is purely for browsing your music but it is such a simple, obvious UI that it merits mentioning. Hopefully its ideas can be intergrated into a more encompassing media browser.

(lg, xl)
(lg, xl)
(lg, xl)
(lg, xl)
Leave a Comment more...

RDP over SSH

by volve on Jan.19, 2006, under articles, linux, software

I’d been having some annoyances with RDP (Remote Desktop) over SSH. The primary source of annoyance stemmed from the Win2k/XP client not allowing you to connect to your local IP regardless of port, forwarded or otherwise. Luckily, it isn’t actually clever enough to know that the address is also tied to the loopback device (one of Microsoft’s little liberties that turns out to actually be handy – who knew?!). So, here’s a solution that’ll save you time struggling and cash from buying an application such as WiSSH that is entirely unnecessary.

(continue reading…)

Leave a Comment more...

rant regarding media servers

by volve on Jan.03, 2006, under linux, media storage, software, ui

I was originally commenting on an article on Engadget but felt like expanding it a bit here.

Ok, what everyone has to remember is that the User Interface of whatever is presenting you with your >1,000 DVD library has to not just be good, but has to be GREAT. The only GREAT interface I’ve found is from Kaleidascape but sadly that’s only inside their $20k media server (nuts!). In looking at the Niveus and Escient screenshots, they look like rejected 80s MTV visuals… Don’t even get me started on MythTV, Meedio, DVD Lobby or the like; goodness.

Although not leaps and bounds better, I am very happy with Xbox running Xbox Media Center. I have my 2TB library ripped to my file-server and the Xbox Media Center software is by far the most friendly and elegant for access. However, even this isn’t a match to the Kaleidascape UIs. Frankly, I’ve given-up and settled for writing my own interface in Flex. Not sure when it’ll be released, but it’ll definitely be free when it’s done.

Just wanted to add my thoughts to this debate in the hopes of tempering all these new product announcements lately and remind people that a >1,000 DVD library is really pretty useless when you can only see ~9-12 covers on screen at a time… Oh and the Sony XL-1 Digital Living System does look quite impressive, but is still bound by the Microsoft MCE2005 limitations. Sony did have some UI screenshots of a different media server but I can’t seem to locate them right now – more on that later.

Leave a Comment more...

Firefox session extension

by volve on Nov.17, 2005, under software, web

As it caused me some effort to actually locate, I wish to share with you this awesome Firefox Extension entitled SessionSaver. The below description does not do the usefulness justice. The version at the link below works with Firefox version 1.0.x and 1.5. Recently the Mozilla team have implemented automatic session restoring upon a Firefox crash (maybe even simply a quit) for the 2.0 version, which is excellent. I’ve always loved Opera’s ability to remeber everything a user was doing when the browser was closed – definitely a step in the right direction.
Download SessionSaver from:
[Description from the page]:

“SessionSaver restores your browser -exactly- as you left it, every startup, every time. Not even a crash will phase it. Windows, tabs, even things you were typing — they’re all saved. Use the menu to add + remove sessions; right, shift, or middle-clicking will delete. “Simple mode” for peace of mind, or “Expert mode” for advanced flexibility. Just Click. Install. Rad.

Added TextSaver: everything you type, saved (even in frames). Added RemoteSync: session-syncing between browsers (syncs Adblock, too). Added intelligent postData-restore. Added various patches + bugfixes, per discussion in the official support thread.”

Get Firefox

Leave a Comment more...

Looking for something?

Use the form below to search the site:

Still not finding what you're looking for? Drop a comment on a post or contact us so we can take care of it!