Date: Tue, 10 Dec 1996 22:28:45 -0800 (PST) From: "Bryan K. Ogawa" <bkogawa@primenet.com> To: vlad@dusk.net Cc: freebsd-isp@FreeBSD.ORG Subject: Re: Backup.. Message-ID: <199612110628.WAA28001@foo.primenet.com> References: <199612090813.EAA00902@eternal.dusk.net>
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In localhost.freebsd.isp you write:
>Hello =)
>I am looking for recommendations as to what
>to use for a backup.
>I am leaning towars a jaz drive due to its
>storage capacity, however am not absolutely
>certain.
>(I'm looking for a good, fairly fast type of
> backup that is also priced decently).
>Could someone enlighten me as to what the pro's
>/ con's ( other than the obvious ones ) are,
>and also perhaps make a recommendation.
Here's my thinking on this subject. Please feel free to chime in...
1. There are a few basic factors you could be looking for in
removable backup solutions:
a. Drive Cost (how much will it cost initially?)
b. Media Cost (how much will each backup
c. Size (how big a backup can I make?)
d. Reliability (will it keep?)
e. Other
2. In most cases, performance (speed of backups) is less important.
If I can find something big enough and smart enough to use only
one backup medium per day, I can do my backups at night, from
cron. Speed only matters if someone has to watch the backups
being done, or is waiting to use them, or if a machine must be
offline while the backup is being done. Therefore, it's more of a
factor if I'm using this to transport files from one place to
another or if my drives are much larger than the devices.
3. You can use a second fixed disk to mirror your first one. This
doesn't let you do off-site storage of your data, though. I'd
disqualify this unless you have some good reason.
4. I'd also disqualify a bunch of small (40-80-120mb) QIC solutions,
because they're small, and because they're not well supported
under FreeBSD from all I understand. In fact, I'd probably say
"SCSI only" and be done with it. As far as size, I'd say a
hundred megabytes, at least, preferably much more.
5. The things that I can think of that fit into these categories:
Note -- all prices in US dollars.
Legend:
+ clearly positive point
= may be positive or negative
- negative point
? something to think about or which I don't know the answer to
a. DAT drive
+ Extremely cheap media -- it costs about $4 - $5 per gigabyte
+ good support from FreeBSD
+ Very widely used format -- interoperability with other tape drives
+ Good storage size -- between 2 and 4 gigabytes uncompressed
= Drive moderately priced -- $600 (potentially much less)
- some DAT drives are flaky -- incompatible writes and read errors
- slow, linear access medium
? reliability of medium is unknown (I think it's good, but not
great)
? drives variable in speed
b. Exabyte 8-mm drive
+ widely used format -- decent interopoerability
+ good support from FreeBSD
+ medium and hardware supposedly more reliable than DAT
+ extremely cheap media -- $3 - $8 per gigabyte
+ good storage size -- between 2 and 5 gigabytes uncompressed
= still magnetic medium
- drive more expensive than DAT -- $1400 for drive
- slow, linear access medium
c. Travan TR-4 drive / QIC wide
+ cheap drives -- about $400
+ very rugged medium / hardware -- supposedly very reliable
+ good storage size -- 2 to 4 gigabytes uncompressed
= moderately priced medium -- $10 - $20 per gigabyte (most expensive tape)
? presumably FreeBSD support good?
- slow, linear access medium
d. Jaz drive
+ Extremely fast medium random access medium -- speed comprable
to fixed disks
+ cheap drive -- about $400 - $500 (including one cartridge)
+ good storage size -- 1 gigabyte uncompressed
+ Somewhat common drive makes transferring files easy
- Very expensive medium -- $99 per gigabyte
? FreeBSD supports this as a disk drive, not a tape drive
? This medium is may be more fragile than tape ?
e. Zip drive (SCSI, not parallel)
+ Extremely cheap drive -- about $100
+ Very common drive makes transferring files easy
= slow, random access medium -- speed much slower than fixed
disk, but random access and much faster than tape
- Very expensive medium -- $100-$200 per gigabyte
- very small data size -- .1 gigabytes uncompressed
? FreeBSD supports this as a disk drive, not a tape drive
? This medium is may be more fragile than tape ?
f. CD-R(ecordable) writer
+ Medium almost universally readable -- produces CD-ROMs
+ possibly better durability -- non-magnetic medium
= Moderately priced drive -- $400 - $600
= Moderately priced medium -- $25 per gigabyte
= Moderately sized medium size -- .6 - .7 gigabytes uncompressed
- Medium can ONLY be written once, increasing medium costs
- proper writing can be very tricky and is (relatively) very
hardware-intensive
g. PD drive (rewritable optical cartridges)
+ Medium is very reliable -- non-magnetic
+ rewritable medium
? moderately expensive priced drive? (I think they're about
$800-$1000?)
+ moderate to good sized medium -- .6 to 1.3 gigabytes uncompressed
- moderately expensive medium -- $80 per gigabyte
? unknown FreeBSD support
- fairly esoteric medium
I ended up choosing a DAT drive, because of all the positives, and
because I was able to minimize a number of the negatives (I got mine
for under $400 with a 6 year warranty, reducing the price and
reliability questions, and I don't care about speed).
Personally, I think that the Jaz drive doesn't make a good backup
solution because of the high media prices (I picked up 3 DAT tapes so
that I can do Grandfather/Father/Son backups, which is easy if the
tapes cost $9 apiece). You're paying for a lot of performance (like a
hard drive), which is IMO a waste if you're not using it 99% of the time.
However, as a second fixed disk for extra files, it may be a great
solution (keep it mounted with extra OSes or extra FreeBSD
partitions).
That's what I think.
Some questions while I was making this:
1. Are PD or other Optical drives supported under FreeBSD?
2. How reliable is DAT, PRESUMING that you get a proper write the
first time, esp. compared to 8mm?
3. Travan medium is supposed to have good reliability, right?
4. How reliable are CD-R? I've heard that they're much easier to scratch.
I hope that helps.
bryan
>Thanks in advance,
>Christian
>--
>Christian Hochhold | Dusk.net Internet Services
--
bryan k ogawa <bkogawa@primenet.com> http://www.primenet.com/~bkogawa/
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