Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: Concorde-SST on September 25, 2005, 01:35:08 pm
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Hello guys,
I work with an apple G5 and OSX 10.4. I´ve got a LaCie Bigger Disk
Extreme with 1 Terabyte full of photoshop files - now since the
disk is full I don´t want to make extra DVD backups (if so, I´d need
200+ DVD´s!!).
And I heard something about tape backups - but unfortunately never
saw one on a mac (semiprofessional user).
Is there anybody who can help me getting some informations?!
thanks very much!
Andreas Suchert
Concorde-SST
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Don't bother with tape. It's slow and exprensive, and You'll get a much faster, cheaper, more reliable, and easier-to-use result if you buy a Firewire or USB 5.25" drive enclosure and a removable drive docking system with drive tray that adapts a standard 3.5" IDE drive to the enclosure. Buy some IDE hard drives and extra drive trays to match (the extra trays are about $12 each) and you have backup storage limited only by the size and number of drives you purchase. Then simply copy the folders from your terabyte device to the external drive and swap drives when they get full.
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Excellent advice! Tape is so slow as to be a liability
But Andreas, I have an old LV-SCSI tape drive that is yours for the asking if you really want to go that route :)
Chris S
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Don't bother with tape. It's slow and exprensive, and You'll get a much faster, cheaper, more reliable, and easier-to-use result if you buy a Firewire or USB 5.25" drive enclosure and a removable drive docking system with drive tray that adapts a standard 3.5" IDE drive to the enclosure. Buy some IDE hard drives and extra drive trays to match (the extra trays are about $12 each) and you have backup storage limited only by the size and number of drives you purchase. Then simply copy the folders from your terabyte device to the external drive and swap drives when they get full.
Yeah, thanks Jonathan,
I think you´re right. I´ve looked around and found tape streamers
to be very expensive. Yes, they´re slow, but I don´t care, just for
security it will be ok. For the fast work I use the big disk.
I think I´ll purchase another LaCie disk - a 250GB or 500 GB one
and staple them - or if I find something like you recommended.
For Macs you don´t have much choice...since I don´t have IDE,
my ports are S-ATA, FW800, FW400 and USB 2.0. I think IDE
would be too slow.
No thank you, Chris, keep your old tape streamer :-) Btw - for your
videos - what storage solution do you use?! - see you in Namibia! -
best regards,
Andreas Suchert
Concorde-SST
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The drive type is determined by the enclosure you get, which determines whether the drive that goes in the enclosure is IDE, SATA, or whatever. The only thing that matters to the computer is whether the enclosure has USB or Firewire connectors.
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Andreas ,
As Jonatham and Chris suggested, I would stay clear of tape backups. But if you insist, Exabyte (http://www.exabyte.com/company/press/display.cfm?id=1839) provides - expensive - Mac OS X compatible tape systems.
Francois
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Thanks,
Exabyte really is pro stuff I guess - and too expensive for
my needs. I just don´t understand why they ´re that
expensive - I always guessed that harddisks are harder
to manufacture than tape drives - but maybe its economics...
Another friend guessed to buy another HDD and wait for
the upcoming new DVD standard (either BluRay or HD-DVD -
I for my part hope for BluRay - more capacity!).
Well, time will tell - but for now I´m travelling again...
thanks again,
best,
Concorde-SST
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Jonathan, Do you have a particular FW or USB hotswap/tray system you favor?
Chris, Jonathan, anyone:
What about SATA systems and the host card, such as here (http://www.macgurus.com/productpages/sata/hotswapsatakits.php) or here (http://www.sonnettech.com/product/fusion.html) ? Are these better, faster, more reliable, futureproof, cheaper...
I will soon face the same issue as Andreas but am considering getting back to video, now it's HD and accessible $wise. So RAID/speed might be more important to me than sheer storage space.
Chris - since the video threads disappeared, do you have thoughts on a system that could serve this kind of double duty : sometime RAID for video, periodic swap for archive/backup, or would it just be add FW drives as you need the space and use an internal SATA drive for video. I just haven't kept up with the recent developments, so please forgive any newbie type questions
Thanks
Andy
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The enclosure I'm using is a USB 2.0 made by ADS Technologies, and the drive dock I'm using is the SanMax PMD-96i-IDE mobile dock. The enclosure is probably not the fastest one out there, but it was cheap and has been very stable.
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Jonathan, Do you have a particular FW or USB hotswap/tray system you favor?
Chris, Jonathan, anyone:
What about SATA systems and the host card, such as here (http://www.macgurus.com/productpages/sata/hotswapsatakits.php) or here (http://www.sonnettech.com/product/fusion.html) ? Are these better, faster, more reliable, futureproof, cheaper...
I will soon face the same issue as Andreas but am considering getting back to video, now it's HD and accessible $wise. So RAID/speed might be more important to me than sheer storage space.
Chris - since the video threads disappeared, do you have thoughts on a system that could serve this kind of double duty : sometime RAID for video, periodic swap for archive/backup, or would it just be add FW drives as you need the space and use an internal SATA drive for video. I just haven't kept up with the recent developments, so please forgive any newbie type questions
Thanks
Andy
Hello Andy,
I think you may look to LaCIe too - they have some nice things like
you showed. The Burly things look questionnable to me - they
seem to be a lesser copy of LaCie.
Look here:
LaCie (http://www.lacie.com/products/range.htm?id=10033)
I may be biased - because I like the design of LaCie...and since four
years I never had any issues with those products. They may be
a little expensive, but worth the cost IMHO.
About being futureproof - no, they aren´t of course. You always will
be forced to step up with standards in storage. Better? I don´t know.
Faster? Yes, they´re much much faster than tape.
Reliable? I don´t know, never used tape. But I think tape is more
reliable.
Also - I´d be interested in what Chris has to tell - I suggest him
and Michael Reichmann to invest something in Forum backup!
best,
Andreas.
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Andreas,
Thanks for the thoughts. I didn't mean futureproof forever
I'm still in the early stages of research on this, and would like to stick to IBM/Hitachi or Seagate drives. Maxtor and WD are ones either I or friends have had problems with. Do you happen to know what LaCie uses? Their swappable units seem quite pricey but they do "look" nice and I've heard quite a few speak well of them.
Thanks Jonathan, I'll check them out - I like the combo of cheap and stable for backup/archive
Andy
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Andreas,
Thanks for the thoughts. I didn't mean futureproof forever
I'm still in the early stages of research on this, and would like to stick to IBM/Hitachi or Seagate drives. Maxtor and WD are ones either I or friends have had problems with. Do you happen to know what LaCie uses? Their swappable units seem quite pricey but they do "look" nice and I've heard quite a few speak well of them.
Thanks Jonathan, I'll check them out - I like the combo of cheap and stable for backup/archive
Andy
Andy,
you´re welcome - well, for the foreseeable future I think
you have to look at the MTBF-Time (mean time between
failure or so) of HDD´s - good ones have about half a
million hours (but I may be wrong already) - and this
adds up for continuous use of real life time of about three
years.
I won´t use them longer for critical data - then I´d buy
another one or swap or backup. Some people use them
for only two years. Its just how much you value your
stored data.
For maximum security a RAID array is the best solution
IMHO - so more than one identical copy of data on an
array of HDD´s. Expensive, but fast and safe!
A friend of mine is a Seagate freak - they are some of the
best ones around - especially for Windows users.
No, I don´t know which brand LaCie
is using - but for the given price and quality I guess one
of the major manufacturers.
The internal HDD of my Mac is a Maxtor - I´ve got the
Mac for about two years and never had a crash or some-
thing like this - maybe its the Mac?! :-)
take care!
Andreas.
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Reliable? I don´t know, never used tape. But I think tape is more reliable.
This is sadly not the case. Tape cartridges are more prone to wear out with use and become unreadable than hard drives, and are also more likely to deterirate in storage. Tape requires physical contact between the R/W heads and the tape, which means wear occurs on the surface of the medium each time the tape is read or written. Additional wear occurs as the tape is transported through the mechanism of the tape ad drive. Because the tape must be thin and flexible, it must be made of materials that are more fragile and prone to break down over time than the aluminum or glass of a HD platter, and if the tape is stretched, crinkled by a drive malfunction, or becomes brittle and cracks, data is lost.
The only mechanical wear points on a HDD are the bearings of the platter spindle and the arm housing the R/W head(s). The R/W heads and the platter never touch, and consequently there is no wear there. I've had far more problems with tape data loss than hard drive crashes, and most hard drive crashes are due to viruses or OS glitches, not physical malfunctions.
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For Macs you don´t have much choice...since I don´t have IDE,
my ports are S-ATA, FW800, FW400 and USB 2.0. I think IDE
would be too slow.
Don't worry about the speed differences between SATA and IDE. With todays current drives there really isn't any difference. Very few SATA drives are faster than IDE drives.
And as said, as far as closures go, it doesn't matter since either tech will slow down to the speed of either FireWire or USB 2.0.
Do you happen to know what LaCie uses?
Maxtor. At least mine is. Can't speak for the newer models.
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Jonathan,
I guess you´re wrong about reliability of tapes. Of course you´re right
when you use them too often, they´ll deteriorate. The same goes to
Harddisks (but there much longer lasting).
I was guessing to use a tape only once or twice, then store it at a safe
place. Then I guess it is safer than anything else (except optical medias).
If you store them in a small faraday´s box (metal box) in a high and dry
place - then they´re lasting a long time.
Enterprise users will know this better - maybe there are some folks
around who read our thread...
anyway - my decision is now forming without tape medias...
all the best!! + thanks again,
Andreas.
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For Macs you don´t have much choice...since I don´t have IDE,
my ports are S-ATA, FW800, FW400 and USB 2.0. I think IDE
would be too slow.
Don't worry about the speed differences between SATA and IDE. With todays current drives there really isn't any difference. Very few SATA drives are faster than IDE drives.
And as said, as far as closures go, it doesn't matter since either tech will slow down to the speed of either FireWire or USB 2.0.
Do you happen to know what LaCie uses?
Maxtor. At least mine is. Can't speak for the newer models.
Hello Daniel,
O.k. - I agree about speed difference between IDE and S-ATA. A quick
question to my pro friend solved my uncertainty there. He mentioned
that if you have the choice between both of them, you should use S-ATA
because he sees more potential in it - in terms of market spread and
costs. I´m not that much into this - so I have to believe.
I don´t understand why "either tech will slow down to the speed of
either FW or USB 2.0" - can you explain that? I always thought that
these "techs" are separated from each other (at least on my G5 Apple)
so they won´t affect each other´s transfer speed.
And - my big 1 TB FW800 drive is incredibly fast - about 88 MB/s
(but not now - too full) - I can´t see much faster solutions ex-
cept SCSI-320 in network surroundings.
all the best and a great week,
Andreas.
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I don´t understand why "either tech will slow down to the speed of
either FW or USB 2.0" - can you explain that? I always thought that
these "techs" are separated from each other (at least on my G5 Apple)
so they won´t affect each other´s transfer speed.
I guess Daniel wanted to say that the bottleneck was not in the drive but rather FireWire or USB 2.0.
Francois
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I don´t understand why "either tech will slow down to the speed of
either FW or USB 2.0" - can you explain that? I always thought that
these "techs" are separated from each other (at least on my G5 Apple)
so they won´t affect each other´s transfer speed.
I guess Daniel wanted to say that the bottleneck was not in the drive but rather FireWire or USB 2.0.
Francois
Exactly.
FW800 is the only one in the bunch that can match the speeds of a internal HD given the enclosure is well built (although I've seen some FW800 drives that run slower than USB2).
What company built your External BTW?
I guess you´re wrong about reliability of tapes. Of course you´re right
when you use them too often, they´ll deteriorate. The same goes to
Harddisks (but there much longer lasting).
I agree with Jonathan's assessment of tapes. In addition, a tape can "bleed" (magnetic data from one part of the tape effects another part of the tape that's in contact with it) over time corrupting data. It's not long-term storage solution by any means.
Corps use them to back up entire servers and/or databases in one swoop and they tend to do so on a regular and frequent basis.
If you want to make a exact backup of one of your disks on your mac, then buy a drive that's the same size as the drive to be backed up. Then use Carbon Copy Cloner (http://www.bombich.com/software/ccc.html) to duplicate the drive.
CCC can be set up to automatically backup on a schedule or just backup a certain directory.
Another solution is to use Applescript to run and rsync backup (http://www.macdevcenter.com/pub/a/mac/2005/07/22/backup.html) which can be run automaticaly via an iCal event.
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I use extra LaCie FW800 D2 drives for all my backups. HDV video is simply stored on the original camera tapes when it is not being edited.
I have used Retrospect for years from the days of backing up to floppy disc sets to today's FW800 drives. But as of last night, I am no longer going to use it.
One of my LaCie drives became corrupted. Unfortunately in a absent-minded moment I used the 'Repair Disk' command of Apple's Disk Utility. I should have used Disk Warrior because without warning, DU overwrote the corrupt directory structure and lost all my files for the authoring of LLVJ-13. No worries I thought, I would simply restore them from Retrospect's files on another drive. Well, all my files for every previous DVD authoring were restorable but not those for LLVJ-13. Somehow my scripting of Retrospect's backups had missed all the new files (I still don't know how). Carbon Copy Cloner from now on. Or a network RAID (http://www.luminous-landscape.com/reviews/accessories/readynas600.shtml)
CS
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Thanks Chris, and sorry to hear about the "forced" switch to CCC.
For your HD editing, do you use the internal (?) SATA in the G5 and find it sufficient? If it meets your needs, it would surely meet mine, and all I'd need would be back-up/archive for my "stills"
Andy
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My bus strategy for video is to keep the i/o on a single fast channel free of other demands.
All apps, utilities etc. live internally; all captured & edited video lives externally on the FW800 drives. I found with FW400 that if multiple demands were made on a FW bus, the signal would often fail. This strategy also allows the video to be portable between machines if I need to edit the same video on different computers.
Chris S
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Hello all,
thanks for all the great informations - I now agree that tape backup
does make sense mostly for enterprise users who do that regularly
and aren´t that restricted by something like a private budget...
I´ve heard about tape "bleeding" - but not in that phrase - thanks
- I forgot that and can agree with that.
Could this happen to HDD´s too? Does anyone has some advice
for storing HDD´s (off-line)? Do they lose magnetization (?) or
could they "bleed" too? Are they being remagnetized automatically
or not?! Would a complete three-way-backup do the trick
(copy the full harddisk to another one with same or greater
size, then copy it back to the original one)?
So I will look around after a new LaCie harddisk - I found them
very reliable to work with an apple computer - since I own one
1 TB (FW800) and four 80GB pocket drives for travelling (FW400).
Chris, I´m shocked about your experience with Retrospect - I was
thinking of buying this software but your experience kept me from
doing this. I´d try the somewhat more simple and hopefully more
reliable CCC software.
Of course a RAID would do the trick too - if you can spare the
money and space (be aware of the noise and the heat-generation!!
A friend of mine works as a system operator for a middle sized
company and says the raid arrays produce so much heat that they
need to be in an special climatized room).
To Andy:
I can´t recommend you to use your internal HDD for HD editing - I´d do it like
Chris mentioned. I was doing that with my photos a while ago but found it
much safer and faster to leave the internal HDD for the OS only and the programs.
Its wise not to fill up the internal HDD more than half of its size - so the HDD
stays fast.
But it depends on your desired use of HD video editing or still photography. If you
do it relatively occassionally, then go for it, otherwise use one or more external
drives. This has become clear to me more than before - thanks to this thread.
so guys,
thanks a lot for all the good advice and
a happy shooting this weekend - fall
colours should be great over the big
pond...
all the best,
Andreas
Nuernberg,
Germany.
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This is sadly not the case. Tape cartridges are more prone to wear out with use and become unreadable than hard drives, and are also more likely to deterirate in storage. Tape requires physical contact between the R/W heads and the tape, which means wear occurs on the surface of the medium each time the tape is read or written.This is sadly not the case.
Jonathan, I do sometimes wonder how you managed to become an expert on everything under the sun. I wish I had your IQ and memory.
However, in this case, as in many others, I suspect, you're talking total rubbish. In long term data storage (e.g scientific data, which I do actually know about), DAT and Exabyte rule supreme. You may have a sort of a point on tape wear, but you see, tapes are not cycled very often. Disk drives do fail, often abruptly. So do disk controller electronics. And interfaces come and go. An Exabyte drive for MacOS will cost around $2000, which, compared to an ever expanding RAID array, is not so bad.
Disks are for online data, essentially, not archival. Digital Tape, with a good cycling strategy, is a safer long term bet. And far, far more scaleable in terms of cost, physical space and data space.
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I have to defend Jonathan here (not nice to say he's talking total rubbish; he isn't). Large volume backup and data storage is perfectly fine on disk. Tape is still used in many organisations but this is transitional. Backup to tape is linear, failure rate is not insignificant, and it's not cheap. It is inefficient and slow. Amazon.com now operate (I believe) the world's largest commercial database, which they run on a grid / RAC architecture: they have to run 24/7, they don't back up to tape. Storage arrays when properly managed using modern manifestations of RAID-type technology don't need backup as they have load-balanced failover. You can take entire disk sections out with an axe and still lose nothing. For business continuity / DR the biggest organisations will replicate the storage arrays remotely: often (and definitely in the case of the global banks) in real time. This is all done on disk. Oracle Corporation operate and host extremely large databases and storage arrays, which they operate 24/7 with zero downtime for backup / replication / patching / maintenance. Know who replaced SUN as their prime hardware platform? Dell. I don't believe you'll find a tape drive in Oracle's Austin datacentre, and I can tell you this first hand.
Disks are for online, not archival? Says who? Old thinking. I've been bitten by tape failures far more often than disk failures.
You can easily and cheaply buy the hardware for a RAID array, and hard disks are cheap and plentiful. Rely on one disk and in the event of a failure you'll get hurt: invest in a sensible storage strategy and you'll easily cope with disk failure.
I can't leave without making a further remark: Jonathan is RIGHT to make sure he knows about data storage - it's his livelihood. In the recent past a photographer who negligently stored film media would end up with damaged originals, even if he could find them. Big bucks were spent on archival storage for film media. For digital, he HAS to understand digital storage: why are you surprised?
Jonathan may not be expert on everything under the sun, but I for one think far too many 'professional' photographers are anything but professional in this modern era. Love him or loathe him, Jonathan certainly is professional.
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Of course a RAID would do the trick too - if you can spare the money and space (be aware of the noise and the heat-generation!! A friend of mine works as a system operator for a middle sized company and says the raid arrays produce so much heat that they need to be in an special climatized room).
At home, I have a total of approx 8Tb of disk storage (not all of it online) in external racks, and operate RAID 5. It generates only as much heat as you would expect from the number of disks you have 'live' - RAID in itself generates no heat. This is not an expensive option: you can buy the requisite hardware online.
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pobrien,
about the RAID + heat - of course I meant the harddisks! They do
produce some heat - especially the ones with high spin rpm and
since they have a BIG RAID (my friend can´t tell it for security
reasons, how big and how it is exactly built in his company).
How did you construct your RAID? RAID 5 is the one in which
you have more than one copy?
Also - I´d like to know how you "archive" your non-live disks -
just leave them in the stack or store it somewhere "safe"?
a great weekend,
Andreas.
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A variation on Jonathan's suggestion: I have a local RAID array (0.8TB RAID in the PC) and do incremental weekly backups to one of two sets of external drives. These are kept in buildings a few miles apart. The drives are replaced every 18 months with ones at the price sweet-spot (~250GB now) and the old drives stored for 18 months too. (So far I've found a use for all the old drives after that period.) This approach is not very expensive (I'm backing up about 0.5TB at present.)
Big RAID arrays are great if done well. At work (not photography) we learned a lesson when a few TB RAID5 array controller died and took out the whole file system. 12 hours later the hardware was fixed under contract, 12 days later the system was up and running (we did not have recent backups). Also our disk failure rate (hitachi, but I don't think that matters) is high compared to MTBF. We suspect poor cooling in the RAID box. If you use RAID as the final resort do it well.
Ken
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whatever. There is too much opinion stated as fact from some people here, and that is a disservice to fellow forum participants. Dell & Amazon may well run multi-million air conditioned multi terrabyte multi redundant backup RAID arrays in offsite data warehouses, but I'm not totally sure how relevant that is to a single amateur, semi-pro or pro photographer looking for a reliable, scaleable and affordable data archival system, which at the same time doesn't need a data tech to run it. I'm not sure what the point about speed is here. So what if it takes all night to do a backup ? If you want a flexible strategy, by all means keep copies of important files on seperate disks, or indeed a small RAID sytem. There are also some fairly breathtaking views on what constitutes "cheap" around here, but then again I wouldn't be surprised if the majority of Canon 1Ds' are used to take photos of cats and grandchildren.
I think the original point of this thread was to investigate tape storage as an option. It is a viable option, and it verges on arrogant, and near-total (I'll concede a fraction) rubbish to arbitrarily rule it out.
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Whatever, David?
I thought the point of the thread was to avoid 200 DVDs, with tape as the method that had been "heard about".
Is it too unhelpful to suggest alternatives that seem to work?
Natually my earlier post was factual. I agree with your point about RAID, which is why I mentioned the RAID problem and the lesson we learned. (We now have an off-site tape backup.) As you imply, the relevance of any of this to an individual depends on their specific requirements, speed, cost per GB etc. But I suggest the best answers to those points may be found on fora dealing with mass storage (I'm sorry, but I don't know of one I'd trust enough to recommend.)
When I looked at tape storage as an alternative I was not convinced tht it was a good long-term solution for my modest needs. Spinning media seemed the best compromise given the extremely low cost and high speed, that won't be true for everyone.
If you were not criticising my post you could have been more specific (no offense taken, of course).
Ken
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David,
I think you are exaggerating a little. That some people
(myself included) veer off somewhat from the original
topic is in my opinion normal and good - at least I find
this. I now have a greater grasp over this background.
It helped me and hopefully other non-responding readers
to shape their eventual decision for a "safe" backup solution.
And yes, I do take besides of my professional assignments
photos of my family and my late terrier dog and am proud
to have high quality photos of those who are my family
and people whom I care most of with the best camera I
have.
"Rubbish" is a quite stark choice of describing some
people´s lines - I think its not polite but thats all
about talking to each other to find a solution to a
question I started.
Remember, there are no rubbish questions, only
rubbish answers. :-)
Anyway, no offense taken on my part.
Have a good weekend!
Andreas
Nuernberg,
Germany.
:blues:
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Ok, ok, I'll shut up. Sorry Jonathan. I'm a bit grumpy due to an enforced stay at home after an unscheduled visit to hospital earlier this week. Sorry.
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David,
no problem, that could happen to me too! Sorry to hear of your
difficulties - get well soon!! After all, we´re just humans with
too much technical things around us....
all the best,
Andreas.
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Just for the general information:
here´s the link for LaCie´s RAID S-ATA Array:
LaCie (http://www.lacie.com/company/news/news.htm?id=10244)
best,
Andreas.
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Jonathan, I do sometimes wonder how you managed to become an expert on everything under the sun. I wish I had your IQ and memory.
Prior to doing professional photography, I spent 7 years as the head programmer and network andministrator for a marketing company, and had hands-on experience with a few different tape backups. I had several unhappy experiences attempting to restore backups from tapes that were unreadable only a few months after being written, as well as the hassles associated with automated backups erroring out due to tape write errors. Eventually I gave up on tape altogether, and built a pair of RAID servers that replicated the data to each other, and got a drive enclosure to regularly back up critical data to portable hard drives for off-site storage. This pretty much eliminated the problems associated with the tapes.
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Could this happen to HDD´s too?
No. HDs store information on metal patters and they do not come in contact with one-another. HDs do not "bleed."
Do they lose magnetization
Yes but it would take a good 400 years (from what I remember off-hand) or more before that would happen.
Look on the bright side DMR, you don't have to stay in the hospital and eat that cheap green jello.
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Andreas, I have an on-board RAID controller in my PC and four external 8-bay SCSI racks. Only one of the racks is 'live' at a time, disks can be hot-swapped within the rack in the event of failure. I mostly use Seagate 350GB disks in the newer racks: best to use identical disks throughout. I've been using this setup for about four years, and in that time have only had two, separate disk failures (both 200GB 10,000RPM Maxtors, oddly enough). I was able to simply replace them, and nothing was lost. The controller and enclosures are Taiwanese-branded items I have only ever seen for sale in HK, China and Taiwan, and they have been very reliable. I don't store copies off site as I'm not commercially dependent on the safety of this stuff, but I would be unhappy if I lost anything! I also store video as well as photos on there, so I need a lot of space.
I have also had too many occurences (in work) of being unable to get tape backups restored, so there's no way I'd use them for my personal stuff. I've also discovered to my cost that CD and DVD media are not as robust over time as we were once led to believe, so for me HDD storage is the only option for now.
RAID 5 isn't quite mirroring - have a look at the table on http://www.midwestdatarecovery.com/raid-array-types.html (http://www.midwestdatarecovery.com/raid-array-types.html) to see the differences. You need a minimum of three disks for it; maximum depends on the specifications of your controller.
My biggest complaint about my setup is the noise from the SCSI disks and fans. If I were to re-build this today I'd look at newer setups you can get using S-ATA, and perhaps find a better quality case with improved noise control.
PS - I took a picture of my little girl holding her cat with my 1DsMkII over the weekend - should I expect a visit from the authorities? ::
PPS - David, sorry to hear you've been below par - I wish you good health.
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seems to be some confusion here between mirroring and archive. I would have said that rAID mirroring is appropriate when you want 24/7 access to data / services, but it doesn't help you if you accidentally delete a file. Archiving on the other hand does.
I'm not going to say anything else on this topic, apart from to observe that tape backup, like everything else, can be done well or badly, and just because you throw a heap of money at it it doesn't mean it's done well. Not including redundancy in a tape backup strategy is living very dangerously. Also, in over 10 years, when I was using professionally in large volume, I never had a DAT (DDR) tape failure. Ever. I did have a couple of drive failures though (Sun units). No big deal, from the point of view of data integrity
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Greetings,
A word of caution on the Mac G-5 OS 10.xxx - there is reportedly an engineering oversight in the hardware as it relates to Firewire writes - they are VERY slow compared to putting in a SCSI card and going to an external RAID - then run SATA drives in the RAID cabinet.
In short, avoid Firewire external drives.
Jack
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Can you provide any hard evidence for this ? I'm using external FW400 & FW800 drives on a Mac G5, and I can't say I notice them being particularly slow...
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Jack,
well, I don´t agree with your opinion. It could be - since I´m not particularly
good at this depth of technicality.
My FW800 and 400 drives are extremely fast, I regularly have 88MB/s transfer
rates from the 800 drive - I don´t consider that as very slow. Maybe you´re
used to an array of SCSI320 RAID stripe set?!
best,
Andreas. :blues:
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Can you provide any hard evidence for this ? I'm using external FW400 & FW800 drives on a Mac G5, and I can't say I notice them being particularly slow...
Same here!
Francois
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My FW800 and 400 drives are extremely fast, I regularly have 88MB/s transfer
rates from the 800 drive - I don´t consider that as very slow.
I wouldn't either but I have a hard time buying that number. The FW800 spec allows for a max transfer speed of 80MB/s but since Apple underrated FW400, I'll believe it's possible for it to reach 88MB/s (though 8MB/s overrating is a bit of a stretch).
However, I have never seen any PATA drive exceed a 60MB/s transfer speed or any SATA drive exceed 70MB/s.
Perhaps your test was read/write and not transfer.
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Daniel,
it was, believe it or not, sustained transfer. But I don´t know how
the program is calculating the speeds, since there is a difference
between 1 MB, being 1000 KB or 1024 KB (which is correct).
I´ve got 6 GB of RAM, dual 2 GHz G5 and plenty of HDD space -
so I guess this speed should be expected (of course only one
FW800 drive is live).
best,
Andreas.
:blues:
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I was told this last week by a buddy that builds Macs. Quized him this morning and here is what I got back:
I couldn't find all the articles I read last week, but in the following, I did read it wrong. This is referring to a FW800 add in PCI X card for running a multiple drive array.
Have to do some more checking to see if it's the same on the Mac's internal FW 800.
http://www.barefeats.com/hard35.html (http://www.barefeats.com/hard35.html)
Last November we discovered a problem with multi-channel FireWire 800 RAID on the G5. The sustained WRITE speed was much lower than SATA... AND... much lower than a Dual G4/1.42 Power Mac with the same configuration (see second graph above).
I've asked around as to why the G5 could only achieve sustained WRITE speeds half that of the G4. Nobody has any hard answers. Only theories. Some blame Apple's PCI-X controllers. Some think it's a G5 firmware bug. Some think it's a deficiency in the PCI controllers or an incompatibility between those controllers and the G5's PCI-X slots.
Two of my colleagues in two other labs with similar setups observed the same phenomenon. We tried different drives, different case kits, and different PCI controllers -- same result. We even tried putting one FW800 card in slot 4 (133Mhz) and one card in slot 3 or 2 (100MHz - different bus) -- same result.
I'm hoping Apple engineers can help solve this mystery since I've passed my findings on to them. I hope it's a simple firmware fix or OS patch -- and doesn't require a Rev B motherboard!
Just offered for your info - don't want to start a range war over this.
Jack
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Quick comments regarding my experiences over many years of running a medium sized medical imaging lab with large amount of data production. Tape (LTO) is economical on large scale but must be cycled to maintain reliability. We interlace four tape sets biweekly with two set kept off-site. Every 18 month, we replace the tapes. Tape is reasonable when dealing with many GB of incremental daily network backup. LTO drives such as Exabyte are expensive as are the tapes. Cheaper tape solution, eg DAT, are unreliable. Used to use DATs and have had some serious meltdowns due to retrieval failures.
For smaller operation, tape is not a good solution. For home (largely my photography studio efforts) I have used CD and DVD-a lousy solution, but am just now switching to 400GB firewire/USB drive with retrospect regulated backup. Again, multiple systems (2), cycling (monthly), one system kept off-site.
I would recommend backup software not file copy-retrospect works. You want to be able to rebuild your entire system relatively effortlessly.
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Yoni,
I agree with your opinion - depending on how much storage you "waste" in
a given amount of time tape may be the best solution. In cases such as I
see mine, I now found out that HDD RAID would be the best solution.
Of course parallel to this I´d use DVD backup, re-do this every 12-14 months.
One copy would be here in my home, the other in a safe room about 130 miles
away.
I don´t need retrospect - just the photoshop work files (heavy layered) and the
RIP print files are backupped. System and programs are readily available on
DVD´s.
I call this my own minimal invasive routine :-)
best,
Andreas.
:blues: :blues: :blues: