WizGidget

One of my church friends Jim asked me about backup solutions, so I thought it might be good to drill into that subject this week.

First, let’s think about why we need backups: data loss. One way you could lose data is if your hard disk crashed, in which case you would most likely lose all of the data you have on that computer. Years ago disk crashes were fairly common, but these days they’re fairly rare. Even so, it’s a good idea to take backups. Another way would be if the data on your disk were corrupted somehow, such as by a virus. Yet another way would be if the computer were stolen, such as having a laptop stolen out of your car. Finally, and most usually, what I call a “short between the seat and the keyboard” — you accidentally delete or overwrite a file you realize you needed. So, there’s three basic modes of data loss: total data loss, partial data loss where the computer becomes unusable, and one or two files.

The fast, easy and fairly cheap way to provide backups these days is using an external USB drive. There’s a bewildering array of these available: I did a quick check of the local office supply chains as well as a major electronics retailer to find a combined 13 different makes of external USB drives. Some of them are intended to be desktop, some are portable — I have two that I carry with me when I travel. Most if not all of them these days come bundled with some form of backup software.

There are several things to look for in an external backup drive and it’s software. First, I’d look for one that can provide an emergency recovery backup. My Maxtor external drive has something it calls “SafetyDrill”, that when combined with a DVD that came with the drive will pretty well put humpty back together again — just connect the drive, boot off the DVD, and follow the instructions. This assumes you’ve taken the SafetyDrill backup beforehand — it can’t recover your data from thin air. The SafetyDrill backup isn’t intended to recover individual files, it’s a disaster recovery tool. Also, my other external drive, a Seagate drive, doesn’t have this feature.

The next thing to look for is the backup software itself. You’ll want something that can take “incremental” backups, which is to say that after taking a full backup you can then regularly backup only files that have changed. You need this feature to recover from those “oops” situations where you deleted or overwrote a file accidentally. If you set the backup software to do an incremental backup every night or every other night, you’ll likely have a good copy of any file you accidentally delete. Which brings up another feature you need: the ability to schedule backups. You also need something that’s going to be fairly easy to use, although I don’t really see how you’d know that before the purchase decision, unless the people at the store have a demo set up for you to test drive.

Next week we’ll continue the discussion on backups.

Spouse Ann asks about ways to speed up her PC.  One easy way is to defragment the disk.  First let me explain what disk fragmentation is. As your computer writes things to the disk, it allocates blocks of data on the disk to whatever file is being written.  Ususally the blocks are allocated in full sectors. Think of cutting a pie —  Ann likes to cut really small slices to get maybe 12 slices.  Then think of concentric circles around the pie that cut each piece into really thin arcs.  That’s about like a sector on a hard disk — it’s a portion of a full circle around the disk.

When you first write a file, generally all of the blocks (sectors) are all together, so it’s easy to read the data.  If you only wrote data to the disk all at once and never erased, you might not ever need to defragment.  But we generally don’t work that way.  We write a little to this file, then write a little to that file, the erase that file.

Let’s say I create a Word document.  I write a bit to the document, and of course save it.  Something else comes up, so I go on to something else, and start creating a new file, which gets written starting with the block just after the last block written for the previous file.  When I go back to the first file again and add to it, it doesn’t have any more free, contiguous space, so it hopscotches over whatever’s there and starts writing on the first free block.  When you erase files, that creates free blocks in the middle of other files, which will then start to be used, but those also are of fixed length, so that leads to more of the hopscotching thing.  That is fragmentation.

When files are fragmented, the read-write head, about like the needle in an old phonograph, has to be moved around a lot (called a “seek”) to find the right blocks.  Also, let’s say the current block I’m reading is on sector 1, while the next block is in the last sector, sector 12 (Ann cut this disk to get lots of pieces).  As the disk is spinning, I have to wait until the right sector comes around before I can read my block, almost a full revolution of the disk. You can see that all the hopscotching and waiting for the slot to come around on the merry-go-round can really slow things down.

Defragmenting reorganizes files on the disk so that the blocks are all together.  It’s an easy thing to do.  Open a Windows Explorer by right-click on My Computer (or the Start button), then click Explore.  Make sure the folder hierarchy is displayed in the left pane (click the Folders button), then expand “My Computer” in the left pane.  Right click on the C: drive and select “Properties”.  Pick the Tools tab of the Properties window; and click “Defragment Now.”  Right-click the disk to be defragmented (C:) and pick Defragment.  I recommend starting the defragmentation just before you wander off to bed — it can take a very long time.

Last week I introduced IPv6, which is the eventual solution to the IPv4 address exhaustion issue.  Besides having a much, much larger addressing space (from 4 followed by 9 zeros to 3 followed by 38 zeros), IPv6 has a number of other features built in,  including some security features.  It’s more complicated than IPv4, which means us propellorheads will have to get bigger propellors.  Probably the biggest issue with IPv6 is that it isn’t compatible with IPv4.  If the equipment is designed for it, such as routers, computers and such, the equipment can handle it, but it’s like having two different networks on the same wire — they don’t talk to each other.

There is some equipment that can translate between the two protocols, but I suspect what will happen is that internet providers will at some point simply stop issuing IPv4 addresses and require using IPv6 addresses.  I don’t think that will happen for several years, but when it does it may mean buying a new router and/or getting some help with reconfiguring the network on our computers.

For instance, I run both a Cisco “Pix” firewall and a wireless router on my home network.  The Pix supports IPv6 at software version 7.0.  I can upgrade the software in the Pix, but I don’t think the model I have can be upgraded past the version I have already, so it’s likely my Pix will become obsolete.  That was an expensive piece of gear — about $500 new.  The modern replacement for the Pix will cost about $350 new, although I might could find a used higher-model Pix that could handle IPv6.  And then again there are probably other firewall-routers out there that would do the same thing(s) for much less.  The wireless router would also have to be replaced — it doesn’t handle IPv6 no way, no how.  Fortunately there again there are better wireless routers on the market that sell for $100 or so.  One of the things I really need the Pix for is getting a VPN (“Virtual Private Network”) connection into my home network from “outside.”  The newer wireless router I mentioned does VPN, so it might satisfy the need within a single network appliance.

It seems likely that most of us will have upgraded to IPv6 compatible equipment by the time it becomes a requirement.  Granted that I tend to run things for years past their normal lifetimes, but I have had to replace our wireless router about 5 years ago when the old one succumbed to a lightning storm, or getting too hot or something.  So, it seems reasonable that it will have to be replaced again eventually, and all the new ones support IPv6, and usually also are faster and more powerful.

IPv6 is supported on Windows XP and later, and although it needs to be turned on and may take some tweaking, after being turned on it should configure itself just as your PC does now when you connect it to your wireless or wired router.

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