BACKUP, OR ELSE |
| by Wayne M. Krakau - Chicago Computer Guide, June 1997 |
| As I write this column I am in the middle of a project to attempt to
recover data for a client whos hard drive on a specialty workstation drive crashed,
but who had no recent backup tapes. Actually, their hard drive didnt just crash. It
MELTED! The plastic gasket that helped seal the insides of the drive oozed out and dripped
sticky goo all over my fingers. |
| The people at Ontrack Data Recovery (800-872-2599) later told me that
this was the first melted drive they had ever seen. They suspect that a broken part rubbed
against the spinning platters of the disk and the ensuing friction generated enough heat
to turn most of the drive into mush. Naturally, no data was salvaged. Remember this drive
the next time someone mentions the reliability of modern computer systems as an argument
to lower their standards on backing up data. |
| This incident illustrates the difficulty of convincing nontechnical
people who have never experienced a major computer disaster that they should take
extraordinary steps, if necessary, to protect their data. In this situation, I feel partly
responsible (and have made a major downward adjustment in my billable hours accordingly),
since I didnt get tough and offer an ultimatum to the client. (Something like
"Back up or I wont deal with you again.") I guess Im just too
soft-hearted to be that nasty. |
| I was lulled into a false sense of security by the fact that this
client was quite cooperative in backing up their file server. When they replied positively
to questions about regularly backing up their specialty system, I ASSUMED that they used
the same definition of "regularly" that I did. A lesson learned: Never ASSUME
that a techie talking to a non-techie is speaking the same language! (Obviously, assuming
anything is dangerous.) |
| Since the backup of their file server was mostly automatable, and the
backup of their specialty system was not (due to the space limitations of their backup
tapes), the specialty backup was given a lower priority. It tied up a valuable computer
for several hours during the day and was somewhat complicated to as well. |
| Just as I was about to sell them a new tape system with much more
capacity and more sophisticated, easy-to-use software, the meltdown occurred. Luckily, all
of the data will be recoverable from an auxiliary database that is on removable optical
disks, but only after a major, time-consuming and expensive process. |
| If this was the only incidence of problems with backup plans, I
probably wouldnt have been inspired to write on this subject. Sadly, at least
one-third of all the prospects I meet have major inadequacies in their backup systems.
Some of these problems are procedural, some are software-related, and some are hardware
related. Since software and hardware difficulties should be detected by a proper
methodology, I suppose that you could chalk them all up as procedural if you wanted to get
picky about such things. |
| These days, there are many options for backup systems. Tapes are
inexpensive when compared to data-recovery fees. More tapes mean more safety IF and only
IF they are used in an organized manner. (Notice that I didnt say
"planned", I said "used"!) |
| For hardware, there are a variety of choices. Travan-4 tape drives can
hold up to 8GB (gigabytes) very inexpensively. DDS-3 DAT drives now hold 24GB. 8mm tape
drives hold up to 40GB. Finally, for those who want serious data storage, DLT drives hold
an amazing 70GB! |
| If thats not enough for you, try getting an auto-changer (a
high-tech juke box). While not all of the technologies Ive mentioned have
auto-changers available for their highest capacities, manufacturers usually catch up over
time. For instance, 24-tape auto-changers have been available for some time for the older
8GB DDS-2 DAT drives. Im sure that some bright manufacturer is working, even now, on
putting a 24GB DDS-3 drive in those changers. |
| Because of the problems inherent in backing up databases while they are
in use, you may feel that you have to compromise your backup process. If your backup
process takes so long it overlaps into normal working hours, or your staff works around
the clock (hopefully with multiple shifts), you have a problem that used to be critical.
Now, all you have to do is get Open File Manager from St. Bernard Software
(800-ST-BERNARD). It is an NLM (NetWare Loadable Module) that runs on your file server. It
allows live files to be backed up accurately by freezing the file and saving ongoing
updates while the backup takes place. After the backup software goes on to the next file,
the stored updates are applied. Once the software is set up properly, it is all automatic
and transparent to the users of the network. |
| Finally, there is the matter of the backup software. Server-based
software is the only way to go with NetWare 4.x. I prefer to use Backup Exec from Seagate
Software (800-234-3793) and have had much more success with their products than any others
my clients have used, but I know that others have different preferences. |
| A key fact is that workstation-based software cant back up the
NDS (Novell Directory Services). Several manufacturers profess to, but, so far, their tech
support personnel could not answer my questions well enough to give me confidence in their
claims. Senior Novell support staff members have confirmed the inability to back up the
NDS from a workstation. |
| Even based on the chance that some company figures out a proprietary
method for backing up the NDS from a workstation, you would be stuck using a method that
was not officially approved by Novell. In that case, just try to get serious technical
support from Novell while you are rebuilding a server after a major crash! |
| If you are stuck using an existing workstation-based backup solution,
then you can download a program called DSMAINT from the Web. This is an NLM that does
Directory Service Maintenance. One trick it can do is to back up and restore the NDS onto
a floppy or some other disk drive. |
| With all users logged out, you execute a procedure which shuts down the
NDS. Then you do the actual backup. This only takes a couple of minutes. Then you reawaken
the NDS. Finally you bring the server down and bring it up again. |
| If, like me, you dont read the directions as thoroughly as you
should before trying DSMAINT the first time, you can set yourself up for quite a scare. I
thought that I could just do the down and up sequence after the backup. I believed that
this alone would reenable the NDS. WRONG! All that does is generate dozens of nasty
messages which seem to indicate that you have permanently lost or at least critically
damaged the NDS. |
| I think I gained multiple gray hairs from that stunt. Loading DSMAINT,
reenabling the NDS, and doing another down and up sequence fixed the self-generated
problem. (So much for the ace systems integrator!) |
| It is important that you remember to do another DSMAINT NDS backup any
time you alter the NDS. If you change anything in NWADMIN or NETADMIN (the Windows and DOS
administration tools for NetWare 4.x), you have altered the NDS. This is also true if you
add, delete, or modify any program that directly affects the NDS. If in doubt, then run
another backup. Scheduling regular DSMAINT NDS backups is an even better idea. As a manual
task that can only be done when nobody is logged in, this might seem inconvenient, but it
is not as convenient as being without a current copy of your NDS tree after a crash. |
| As I write this article, new, lower unemployment figures are being
reported. If you dont want to make your own personal dent in those statistics, then
I suggest you make sure your backup system - hardware, software, plans, and especially the
execution of those plans - really works. |
| ©1997, Wayne M. Krakau |