Post #20,805
12/8/01 8:53:38 PM
|
Flash: backups story, tape at 11
[link|http://kmself.home.netcom.com/Linux/FAQs/backups.html|My recommendation] is tape, preferable SCSI tape, though CDR is acceptable, particularly if you're going to use it anyway. But capacities are lower by a factor of 20 or more.
--
Karsten M. Self [link|mailto:kmself@ix.netcom.com|kmself@ix.netcom.com]
What part of "gestalt" don't you understand?
|
Post #20,907
12/10/01 12:49:34 PM
|
I've got a bad attitude against tape.
It's the seemingly planned obsolescence. I used to fiddle with tape drives, starting with 40MB QIC cartidges. The software and file formats were all proprietary (no, I wasn't running Linux yet, therefore no tar straight to device) and worst of all, when a new tape format came out with much more capacity, it wouldn't read my old tapes. These reasons are also why I'm leery of these high cpacity removable media - Zip, SyQuest drives and the like.
I don't mind progress. What I object to is churn. In the CD world, they have the decency to space new formats apart by a decade or two. They wait until there's enough of a capacity increase to make upgrading really worth the bother. And I'm told a DVD-ROM drive will read CDROMs, so when I judge DVD drives are a sufficiently mature technology, I can move ahead without fear. (I can, right?)
BTW, I recently saw a Philipps internal CD-RW for $100. At that price I might be willing to go through the hassle of installing, and to risk accidentally leaving it behind.
[link|http://www.angelfire.com/ca3/marlowe/index.html|http://www.angelfir...e/index.html]
Sometimes "tolerance" is just a word for not dealing with things.
|
Post #20,913
12/10/01 1:31:28 PM
|
Internals are really cheap.
Especially if you're willing to buy one with a "rebate". (I'm not usually.) I think I've seen them for around $50 for a slower drive (after "rebate"). Check places like MicroCenter, BestBuy and the like.
E.g. [link|http://www.shopteac.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=ST2&Product_Code=1CD&Category_Code=CDI|Teac 12x10x32 CD-RW] internal IDE drive kit (including software, cable, etc.) for $80 direct from Teac. They have a slower drive for $60.
No recommendation to buy these (though I have had good luck with Teac products), just FYI.
I agree with your reticence concerning tape for this application. Tape's not the best for moving between random machines.
Cheers,
Scott.
|
Post #20,959
12/10/01 10:21:02 PM
|
That's not SCSI. DAT / DDS
You're confounding consumer technology with professional tape archival solutions. AFAIK, all DDS (what most people call "DAT") formats are forward-compatible. That is, a DDS tape from an older unit is going to work with a newer one. I've never used QIC, Travan, or other tape formats, and don't plan on doing so. I do the math on my backups page -- once you're past about ten media units, SCSI DDS is worth the cost. For a drive plus ten tapes, your cost per GB is about $3. This is about comperable with current disk drive costs. The difference is that your incremental cost per GB is $0.75. CDR compares (I'm using 650 MB and $0.50 per disk) at $0.76/GB. This neglects compression, but both units should give comperable performance. The advantages for tape: - Low per-unit cost.
- High reliability. Both media and units have a long track record of reliabile use. Media stores well.
- Relative insensitivity of recording to stream buffering. Your tape writes aren't going to be trashed by a system which gets periodically pegged.
- Reusability. The duty cycle on tapes is high -- DLT is rated at 1 million head passes, DDS is lower (and requires cleaning), but respectable. Media is cheap enough that replacing questionable media is a no-brainer.
- Capacity. A 20GB tape provides 30 times the capacity of a CDROM. With single disk sizes blowing through the 100 GB threshold, a CDROM is to your hard drive what a floppy was to a 250 MB disk in the early 1990s. DVD helps the situation a bit (18 GB capacity), but still has the problems associated with creating backups -- a single glitch can blow the job.
Take care to note the distinctions between what are typically professional solutions -- DDS, DLT, AIT -- and consumer technology: QIC and Travan. In most cases, consumer technologies favor low aquisition cost (the drives are cheap) and high media costs. There's little premium on reliability or media compatibility. I have to agree with you regards removable storage. I still use floppies only. If I can't net it, it doesn't happen. CDR is the de-facto sneakernet standard these days (I'm not saying CDR doesn't have its uses). But as floppies were never really suited to backups, CDs, IMVAO, aren't either. In the PC world there was also the additional hassle when dealing with tapes that you were always intermediated by some sort of archival software. There's a strong reason why I advocate use of simple, standard, tools, such as tar, over other tools. --
Karsten M. Self [link|mailto:kmself@ix.netcom.com|kmself@ix.netcom.com]
What part of "gestalt" don't you understand?
|
Post #20,983
12/11/01 2:47:55 AM
|
DDS will live forever :-)
As will DLT.
Travan, QIC, all them? Crap, the lot of them.
Use what the professionals use. And that's DDS for small systems, DLT for middlin' ones, and AIT/Mammoth II/Ecrix for really bigass ones :-)
Peter
Shill For Hire
[link|http://www.kuro5hin.org|There is no K5 Cabal]
|
Post #20,987
12/11/01 3:23:00 AM
|
Cheapness of CD/RWs
Last 2 I bought, over ~ 5 month span - were $90 for first, 50 for last, in July. Now that is after the accursed rebate scam which forces you to keep all paperwork and put a stick-on on fridge, to make sure your check does come. PITA and smarmy as a M$ press release. But *cheap*.
Anyway the Pacific Digital 8x8x32 thus far does what it says, no sweat with Roxio 5.0 and, it's past infant mortality. Incremental 'big floppy' mode: reeel handy. Backup entire MAIL folder with not even perspiration. Why be selective at 16\ufffd/700 MB?
FWIW
Ashton
|
Post #21,094
12/11/01 7:38:56 PM
|
What's the shelf-life of hard disks?
My backup requirements are for about 60gig, most of which isn't going to change over time. Music files. At the moment I'm tightrope walking without a net, ie my data isn't exactly backed up. Should I need to recover it, it just means a revisit to all my CDs and a massive re-rip and re-encode option.
(I guess shold the worst happen it would give me the opportunity to re-encode all the ones I did using Blade many years ago...)
Anyway, I think in this case the cheapest backup method is buying a 60 gig hard drive, copying everything over to it, and sticking it in a safe place somewhere. I don't have any detail on how modern hard drives cope with looong periods of inactivity, but it's sounding like an alright backup system to me. Not to mention very fast, and very easy. Even if a shelved HD only lasts a few years, how much is 60 gig of storage going to cost in five years time?
So, how dumb is it? Sure, I haven't given it a lot of thought, but the answer so far seems to be 'not very'.
Of course, I may be missing something.
On and on and on and on,
and on and on and on goes John.
|
Post #21,108
12/11/01 9:40:57 PM
|
Sounds sane to me.
I've spent some years around an odd assortment of mechanisms. But not an expert on the exact "aging points" of quiescent HDs. There aren't many big electrolytic capacitors in there, just a few small - and maybe a few Tantalum teardrops still. The prolly pretty fancy lubricants are within a filtered clean environment.
Given experience with old and new test eq., electronics - my guess is that it would be well to fire up such a HD periodically, annually anyway; more often if EZ and you're paranoid. This would redistribute the motor, bearing lube and reform caps. Against this is: most failures occur on start-up/shutdown. But leaving it years? not good I think.
I always use SpinRite on any new HD before trusting it; it's easy, thorough and - you get a free fresh rewrite of the magnetic domains for every bit = including the lo-level format. I've never investigated the physics of the effects of earth magnetic field (with numbers) vs. the B/H curve of the latest crop of coatings; so it's only hearsay for me that - over time this phenom aids in the 'bleeding' of the local N-S poles, blurring that difference which the read-head must discern. (Worse for certain bit patterns)
Running SR each year or so - would certainly give the heads a flying workout.. Gets it up to equilibrium temp = good. If no SR? Hell just defrag instead, tho it won't need it. I'd keep it in a zip-plastic bag, maybe with a small desiccant pouch, just for the hell of it. Dunno what kinda fungi dwell in the wilds of Oz but - I saw Walkabout! :=\ufffd
Anyway the price is right - we're accustomed to thinking that a random access device is er overkill for such purpose. It seems that Moore's Law has made it so cheap we can forget that one (!) HD certainly appeals to my own keen sense of laziness about massaging such stuff.
HTH,
Ashton
|
Post #21,119
12/11/01 11:25:16 PM
|
Being on the other side of the world and all...
I'd best store it upside down :)
Walkabout - that was the one where that rude gentleman sacrified a VW Beetle (and himself) wasn't it? Still haven't seen more than the first 20 minutes of it. (One of these days, etc, etc)
I guess the other approach I could have to backing up is to mini-Napsterise it. Ok, Distribute is the word I'm looking for. Store a bit of the collection on each of the PCs around the place, so if one does go titsup.com, at least I'll only have lost a chunk of the collection. The single-drive-on-a-shelf is much more environmentally sound, though.
On and on and on and on,
and on and on and on goes John.
|
Post #21,121
12/11/01 11:32:38 PM
|
The DeSitter method
That is what Desitter wanted to do with his desktop system, use a second hard drive to copy the data files over to, and make backups on.
IDE hard drives are so cheap these days you can buy a 60G EIDE hard drive for under $150 at most consumer electronic stores. Cheaper than most tape drives.
|
Post #21,602
12/15/01 5:15:44 PM
|
Philips CD-RW
You may want to do a little research on that drive before you buy. I had a PCRW804K (sold as "CDRW 800 Series") that disintegrated over a period of about 8 months. Usage was very light. I think the thing burned about 15 CDs before it quit completely.
A trip around groups.google brought up a truckload of postings of people with the exact same problem: output power calibration fails, the OPC area eventually is written full, and the CD-R becomes unusable.
There are also some references to it not liking cheap CD-Rs. Some people recommend updating the firmware, but that seems to invalidate the warranty. And I spent a day finding the necessary files because Philip's website is a complete disaster (built for IE, different paths onto the site lead to different results, claims not to know the CDRW804, ...)
|
Post #21,738
12/17/01 2:23:35 PM
|
If you want a good CD-RW...
...go Plextor.
They'll burn on just about any cheap-ass Costco special CD that you pick up, and will read damn near anything, regardless of the scratches on the surface.
"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche
|
Post #21,078
12/11/01 5:58:23 PM
|
Interesting.
There's [link|http://slashdot.org/article.pl?sid=01/12/11/2030211&mode=thread|a story on SlashDot] about backup up a moderate amount of data. A few posters brought up the ADR technology that [link|http://www.onstream.com/|OnStream] is selling. A few less mentioned [link|http://www.ecrix.com/|Ecrix].
Now I've been lusting saving for an Ecrix drive for some months, but I was wondering if (anyone here thinks) the ADR stuff was better tech. I hadn't heard of it before.
Wade.
"All around me are nothing but fakes
Come with me on the biggest fake of all!"
|
Post #21,098
12/11/01 8:58:01 PM
|
My impression is avoid OnStream, but others may know more
Barry R really liked Ecrix, although he's moved on the bigger things (AIT IIRC).
And, I recall hearing bad things about OnStream, but don't remember the details.
Tony
|
Post #21,125
12/12/01 12:38:43 AM
|
AIT is really expensive.
Or it was last time I looked. I might look again.
Wade.
"All around me are nothing but fakes
Come with me on the biggest fake of all!"
|
Post #21,604
12/15/01 7:43:38 PM
|
OT: No good info, only responding
> Barry R really liked Ecrix, although
> he's moved on the bigger things (AIT IIRC).
Acck, my ears are burning.
Here's my progression:
QIC - not consumer, no matter what anyone says, just
old. In those days, the only competition other than
mainframe 9 track and 3480 was Exabyte, which had
a horrible history.
DAT - 2GB. When I had 3x600MB o'disk it was fine.
Original DLT in a 7 slot autochanger. Fast if you
could feed it, HORRIBLE if you could not.
DAT 4/8 GB (I think). Just because I needed to read one.
Original Exabyte, to read from an RS6000.
DUAL AIT in specialized enclosure with compression
card. Cost me $22K for 2, ie: 4 drives. Was to backup
300GB. Too pricey, but big and fast.
Then I did a little dance with ECRIXs. Bought about a dozen of
them. Sprinkled them like fairy dust. Too slow, though,
for any backup > 100GB, and when I do one'off backups
by hand, for panic, way too slow. 3-6MB per second.
Restore time was pretty bad too. Very cheap for the
capacity, though.
Now I'm in love with Exabyte Mammoth M2 in EZ17 robotic
enclosure, 7 tapes. $6K for the box. Backup runs between
10 - 25MB per second, depending on compressability. Each
tape holds about 70GB already compressed data, 100-200GB
raw data. Restore runs at about 15-30MB per second
and that is what REALLY counts when you are sweating. I
currently have 8 of them.
|
Post #21,605
12/15/01 9:42:23 PM
|
BTW, did you see that Exabyte bought Ecrix?
At work, we're using DAT-3, but are getting close to its limits. So I did some quick research to see what the options cost, and found out the Exabyte had done some buying.
$6K is too much for us; realistic max cost will be $2K (and $1.5K is better). I didn't find any loaders in that price range, but did find DDS-4, Exabyte Ecrix, AIT, and DLT drives. However, any new purchase is probably six months away.
Tony
|
Post #21,610
12/15/01 11:11:16 PM
|
So, the question now is:
Did they buy it to kill it - or did they buy it to sell the product.
More often than not, purchases by an "established name" are to kill a threatening technology.
[link|http://www.aaxnet.com|AAx]
|
Post #21,613
12/15/01 11:48:04 PM
|
Well, Exabyte has already added Ecrix products to their site
so it looks like they will be keeping the produts; I hope they don't kill them.
If the Ecrix's slower speed isn't a problem, they definitely have a great price (well under $1,000) for the storage (33G uncompressed), plus I like the fact that it's not a helican scan tape (like VHS or DDS). To me it appears that the Ecrix products fill a different niche than Exabytes.
Companies buying other companies just to kill them (e.g. Mathworks recently did this) or suck the customer base dry (e.g. CA) really ticks me off. /end of sermon
Tony
|
Post #21,117
12/11/01 11:07:44 PM
|
OnStream has real problems.
One is whether the company is still alive, having filed bankruptcy earlier this year, and how long they may be alive if they still are.
The other problem is even more serious. OnStream drives are not standard SCSI devices. They require proprietary drivers, which may work on some versions of some operating systems.
The company was founded by the same crew that produced the least reliable tape drives seen in recent times, Colorado. I suspect they could still have the same attitude on quality.
I wouldn't touch 'em with a barge pole.
[link|http://www.aaxnet.com|AAx]
|
Post #21,126
12/12/01 12:39:21 AM
|
Thanks.
They do sound like something to steer clear of.
Wade.
"All around me are nothing but fakes
Come with me on the biggest fake of all!"
|
