Read-Only Switch for External Hard Drives

As a followup to my recent post on backups, let’s say you use an external hard drive to make backups. If you’ve had some malware blow away your data on your local hard drive, you now want to be extremely careful while handling your backup copy. I certainly wouldn’t want to mount my external hard drive with the risk of malware deleting my only available backup (even if I were careful about cleaning up malware from my system). It would be comforting if I could flip a switch and make the external hard drive read-only after I’ve experienced data loss. 

Back in the day, floppy disks had such a feature, and so did Zip disks. I wish this were a standard feature on external hard drives. And no, “mount as read-only” (which is a software solution) does not count.

Off-Site Backups

I constantly worry about backing up my (precious) photos. A local backup (such as an external drive or Apple’s Time Capsule) isn’t sufficient because my house could burn down. I just heard of a real example (thanks David Kotz) where a power surge fried both the computer and the external hard drives! So, I’m on a quest for the perfect off-site network backup service.

At the moment I’m using two services: Mozy Backup and Jungle Disk. At the surface, Mozy seems like a perfect solution: $5/month for unlimited storage. Jungle Disk uses Amazon’s Simple Storage Service (S3), which charges pretty reasonable rates for storage and transfer. You can check out Jungle Disk’s website for the rundown. What I’ve concluded for now is that Jungle Disk provides more reliable transfers, but Mozy is perhaps more reliable with storing the data itself.

Transfer Rates

Unfortunately, I’ve been getting unpredictable upload speeds with Mozy, and am now no longer confident that my data is getting backed up in a timely fashion. If I shoot 1GB worth of photos, it could be a long time before it gets backed up on Mozy. Just last night, uploading 40MB took Mozy 1 hour and 18 minutes. This is not a scientific comparison, but Jungle Disk took 8 minutes the previous night, for the same amount of data at approximately the same time. In general, Jungle Disk has been (relatively) blazing fast because uploads to Amazon S3 seem to be limited by my uplink bandwidth. Mozy on the other hand is probably being swamped at their end. All in all, I’m very disappointed with my upload speeds to Mozy.

Network Drive

Mozy backs up your data but doesn’t give you a network-mounted drive. Jungle Disk gives you a mounted drive for both your backups and other data. I’ve found it useful for clearing up space on my laptop without having to use an external drive. But I feel that network drives pose a serious problem:

Reliability with Restores

What worries me the most about Jungle Disk is that it is very easy to lose all your backed-up data. For example, a virus or a Trojan could blow away your local files as well as your backup directory on your mounted Jungle Disk volume. Mozy on the other hand would have their version archive intact even if a virus were to delete all my files. Backing up to mounted volumes is thus quite risky.

Now, it turns out that Jungle Disk doesn’t need to actually mount the volume to backup your data, thus mitigating that risk. Still, nothing prevents a virus or Trojan from deleting all your data the moment you mount the volume. If you’re worried about this threat, don’t use Jungle Disk as a network-mounted drive. I think Jungle Disk should make it difficult to delete the version archive, perhaps by requiring an admin password to change the version archive on a mounted disk. 

Conclusion

So for now, I’m going to stick with both services. Jungle Disk seems to be a better backup solution if you’re worried about fires. Mozy seems to be better if you’re worried about malware.

Digitized Signatures

At several grocery stores, I have to sign my credit-card receipt on a “signature capture pad” such as this one. My signature is stored in digital form “affixed” somehow to the receipt. What purpose does that serve? With ink signatures on paper receipts, it is hard to forge or transfer signatures onto bogus receipts. But as for digitized signatures, what prevents the grocery store from “affixing” my digitized signature onto any other arbitrary receipt?

A client could be duped by the store with bogus charges. The store could be duped by a client claiming that he or she never signed that particular receipt.

If the courts assume that these capture pads are trusted devices and that it would take too much trouble to store and paste signatures onto fake receipts, the store wins, and the client is at the mercy of his or her credit card company. On the other hand, I am often amused by how terrible my signature appears on such capture pads. Perhaps clients have an easy out in that case, since the captured signatures look far from authentic.