Nelson, Thank you so much for this comprehensive re-cap.
And, thanks, Dan, for the good program on backing up. I also use an excellent backup program called DATA BACKUP from Prosoft Engineering. http://www.prosoftengineering.com/products/ data_backup_info.php One user is $59 and it goes up from there. I like it because it is so easy to use. Data Backup 2.1 supports OS X 10.4, 10.3 and OS X 10.2 on PowerPC Macintoshes and OS X 10.4 on Intel Macintoshes. Their Web site says: You can backup to or restore from any mounted drive including CD, DVD, ATA, SCSI, FireWire, USB, or networked volumes. They provide a free demo. Cheers! Jane Blake Acree On Sep 27, 2006, at 8:53 PM, Nelsn Helm wrote: > Please correct errors! > > MUG > Backing Up to an External Disk Drive > Dan Crutcher & attendees > September 26, 2006 > > Notes plus some ideas original & not mentioned at the meeting. > > 1. Laptops get stolen, so back them up often. You can prevent most > thieves from reading your stuff by setting the operating system NOT > to automatically log you in when you turn the computer on. See: > System Preferences/ Security/ Automatic Log-in. When you set > computer so, the turner-oner is presented with two blanks, one for > the user name and the other for the password, and no clues about > either. > > 2. Uninteruptable Power Supply: i.e. a battery between your > computer and the wall outlet keeps your computer from stopping in > the middle of critical tasks, and may protect it from power surges. > > 3. But, during thunderstorms, disconnect your computer from power, > cable and telefone lines anyway. > > 4. Similarly, why keep your back-up HD connected when it's not > backing up. > > 5. You need not only a back-up, but an off-site back-up, so when > the house burns down... > > 6. So your hard disk fails. No sweat. You attach your external HD. > Then the same problem that fried the first HD fries the second. > What now? Consider having three back-ups, with one at home and one > away and one in transit or connected to your computer. Rotate them; > overwrite the oldest with the new. > > 7. Consider encrypting your back-ups. > > > BACK-UP WHAT?? > > Most programs that make copies, including Mac OS X, will not copy > all files. Some files are protected by the system, or by the > authors to prevent unauthorized duplication. If you buy an external > HD and copy your internal HD onto it, likely you will NOT be able > to boot from the external drive. This may relate to "permissions". > You can change permissions on any file by hitting [command] [i] and > checking boxes for read only, or read and write, or whatever, but > DON'T DO IT. Doing so may really mess up your computer. If you feel > you must, make a copy of the file to be copied. Move it to the > desktop. Change it's permissions. Copy it as desired, then delete it. > > That said, those files don't change often, and need not be backed > up weekly. > > "Hot" (frequently changing) files are mostly data files which can > be easily copied. So, many persons just back-up their Home folder: > USERS/ YourUserName. That typically will protect your pictures, > documents, music & movies, but not your programs, settings, > preferences, etc., and does not make a bootable back-up. > > > BACK-UP TO WHERE? > > .Mac includes some storage space, but many fewer gb than your HD, > and backing up over the internet is _s_l_o_w_, altho if you do it > while asleep, who cares. Some back-up their email daily, or most > precious files only. > > CD's make a non-magnetic back-up, but you must sit next to the > computer and put a new one in every 20+/- minutes. When you're > filling 20 CDs, 13g+/-, that's a long time to sit by the computer. > CDs do not cost much, but cannot be re-used, so you must keep > buying more. I have a back-up of over 350 CDs. (see 3. below). But, > not being able to re-use CDs also means that when you attempt to > restore from them, you do not risk erasing them (as you do with > magnetic media). Re-writable CDs are not reliable; do not use them. > > DVDs hold something like 10x as much as CDs, so you need not sit by > the computer changing them every 20 minutes, but writing on them > takes longer. If you leave your computer backing up to a DVD and go > to bed, who cares whether it's fast or slow. Like CDs, DVDs do not > cost much, but cannot be re-used. You must keep buying more. Not > being able to re-use DVDs also means that when you attempt to > restore from them, you do not risk erasing them (as you do with > magnetic media). > > EXPECT soon products that will hold much more than DVDs, e.g. BlueRay. > > TAPE drives are expensive and temperamental, and intended for > backing up many computers over a network. Retrospect, qv, was > written to do this. > > EXTERNAL HARD DRIVEs now cost about 2gb/$1, and unlike CDs & DVDs > can be reliably erased & re-used. Newer Macs use Firewire. PCs > mostly use USB2. You can buy HD's with USB2, or for $10 more, with > Firewire, or both. If you plan to use the HD with both PCs and > Macs, buy a HD with both. Any HD is capable of writing data faster > than CDs & DVDs. All in all, an external HD seems the quickest, > easiest, cheapest solution. NB: USB, which Macs have, (not USB2) is > _s_l_o_w_ and UNSUITABLE for backing up gigabytes. [Firewire box + > parallel ATA] > > > BACKING-UP HOW? > > 1. Start by backing up everything, making a simple "mirror image" > of your current boot disk. Note: many programs cannot make a > bootable copy, even tho they look as if they're backing up everything. > > Most then switch to > > 2. INCREMENTAL back-ups copy only files that have changed since the > last back-up, which is certainly cheaper and faster than copying > everything every time. I can imagine two ways to do this: > > a) keep the old back-ups and add the newer editions, so > that everything that was ever on your computer is now available to > you, even tho you erased it from your computer a month ago. This > may not reproduce your folder structure, and may spread files > adjacent on your computer into many different folders. This is > common, perhaps the norm, and leads to #3. > > b) over-write edited old files with their newer editions, > making a "mirror image" like #1, without having to copy everything. > I'm sure some programs do this, but I don't know which and cannot > name one. > > 3. Doing this builds a back-up many times larger than the HD backed > up. After a while, the incremental files grow and get cumbersome, > so most persons REPEAT #1, then delete previous back-ups and > incremental back-ups. Then #2a make incremental back-ups, then #3 > start over. > > SYNCRONIZING differs from backing up, by writing on both HDs. It > puts the newer files on either HD on the other, over-writing any > older version. > > > BACK-UP PROGRAMS > > BACK-UP comes from Apple with a (dot)Mac subscription, and backs up > to most media (likely not tape) and to (dot)Mac. It copies from the > internal HD, but I could not figure out how to use it to back-up > from one external HD to another. You can schedule it to back-up any > time you want, e.g. 3:00 A.M. > > CARBON COPY CLONER: donationware ($5 suggested), can make a > bootable disk image, either an "exact" or a "sparse" copy of any > bootable disk. http://www.bombich.com/software/ccc.html > > CHRONOSYNC "file & folder synchronization & backup for Mac OS X, > automatically synchronizes files & foldrs between your laptop and > desktop volumes or schedule automatic simple backups of important > files, $30 "at http://www.econtechnologies.com/site/index.html was > recommended, but I missed the details. > > RETROSPECT, was long considered "the best," but some up-dates have > made problems. At least four persons at the meeting "used to use" > Retrospect, but do not any more. It lets you select files to copy > (or not to copy), e.g. don't copy files whose names contain "cache" > or "trash", or files in folders with similar names, saving time, > media, etc. After making a back-up, it will, if asked, compare the > new with the old and report errors. Very useful. Very slow. Tape > decks require complicated drivers, because the tape must be moving > at the specified speed for writing and reading. The tape drive may > periodically have to stop. When it does, it must rewind slightly > and get a running start, so that when the critical spot on the tape > passes the read/write head, it does so at the right speed. > Retrospect runs tape drives as well as other media, and costs much, > as do tape drives. Tape, however, is cheap and re-usable. Unless > you're running many computers on a network, forget it. > > RETROSPECT EXPRESS does not write to tape, but does write to other > media. If it lets you select categories of files to copy (or not), > I have not found how to do it. It will, however, compare the new > with the old and report errors. Very useful. Very slow. > Nonetheless, it's a cheap program which allows you to make back-ups > described in both #1 and #2a above. I do not know whether it's back- > ups can be booted. available as part of CheckIt System Performance > Suite from Allume. including SpringCleaning?, TechTool? Platinum, > Retrospect Express? "regularly $100, but often on sale for $80 > > SILVER_KEEPER, free from LaCie at ? silverkeeper.com, lets you > schedule total or incremental backups to any HD, & presumably CDs, > DVDs. http://www.lacie.com/silverkeeper/ > > SUPER-DUPER: shareware costing about $27.95, lets you schedule > total bootable backups, or incremental backups. Recommended by a > user. http://www.shirt-pocket.com/SuperDuper/ > SuperDuperDescription.html > _______________________________________________ > The next Louisville Computer Society meeting is October 24. > Posting address: MacGroup at erdos.math.louisville.edu > Information: http://www.math.louisville.edu/mailman/listinfo/macgroup -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.math.louisville.edu/pipermail/macgroup/attachments/20060929/39c29e67/attachment.html
