Shrinking Tapes And Increasing Bit Densities? 15
MHQ13 writes: "Over the years tape media has advanced greatly, increasing in bit density and decreasing in tape length and physical size while increasing in total storage capacity overall. Although I feel this is a good thing, I am not satisfied. Why are manufacturers not producing longer and larger tapes with current bit densities so that we can have tapes with monstrous total capacities? I would like to have tape media capable of storing a terrabyte or more. This would greatly simplify the nightly backups that I have to perform to backup our numerous UNIX systems. I think it would be a great benefit to be able to perform full backups of every partition of each machine either every night, or at least 2 or 3 times a week, rather than having to perform primarily incermental backups and squeezing in a full backup about once every two weeks."
Monstrous tapes (Score:1)
What about tape changers? (Score:2)
Big tape = big headaches (Score:4)
Bigger/longer tapes have lousier yields. Just like IC's and LCD's, as the surface area increases, the cost of testing and the probability of excess defects increase until it's no longer cost effective to manufacture and sell.
Next, your bigger tape will wear out faster than its smaller brothers because there's a lot more tension in the spools. Sure, the manufacturers find thinner substrate to fit more "linear meter/feet" of tape in the cassette... But this only exacerbates the tension problem even more.
Making wider tapes? Well, now you're talking about increased head size and higher cost (because the head is bigger, or requires more sophisticated control of head-travel geometry).
Besides, do you really want to store all your eggs in one (Terabyte-sized) basket?
AIT-2 Autoloaders (Score:1)
Try tape autoloaders using Sony's rather expensive AIT-2 format: 50GB (uncompressed) raw capacity per tape. Small format, so a smaller capacity autoloader cartridge can be easily couriered off-site.
Some AIT-2 library links for more info:
Anyway, the point is that solutions do exist for those people worrying about the expanding MP3 collections on their drives and all that money in their bank accounts...
Timing... (Score:2)
Re:What about tape changers? (Score:1)
A home computer costing much less than that often has more than 32G of storage. A server with a small disk array can have a LOT more than 32G of data to back up.
Re:What about tape changers? (Score:1)
convience for robots. (Score:5)
I work for STK, the king of high end tapes. Most of our customers report that the majority of their tapes are less then 30% full. Unix can use a tape drive only for backup, the big money in tapes is in the mainframes which uses tape for a lot more. To a mainframe you use cheap tape (and when your data center houses 300+ terrabytes tape is significantly cheaper then disk) to store data for user programs without hitting disk. Not in all cases of course, some things need high speed access to everything, but those jobs that you don't need to quickly generally use tape for their storage.
Becuase tape is generally unformated there is a much higher bit density, but there is no random seak on write. You can write the whole tape, or you can advance well byond the end of the last data section to make sure you don't over wright something. Because of the danger of starting before the end of the last section few people bother to write two different data sets to a single tape.
Don't overlook access time either. Tape is liniear, if you need something at the very end of the tape you need to read the whole tape to get to it, with small tapes that can already take several minutes. Do you really want to wait? Are you sure? Backups are nice and all, but if you don't restore from them what is the point? If a single tape that holds a terabyte would work for you, then so would a good RAID-5 (or mirroring) Disk system. If you want your backups to not only deal with disk crash, but also human error deletin a needed file, then tape is the solution, and smaller tapes make it eaiser and faster to get to the one accidently deleted file.
If you are having problems manageing your tapes, our salesmen will be happy to sell you a multi-million dollar robotic library. You should be investigating these systems as the better solution to your problem. I would guess that a smaller system would serve your needs just as well, from either us or our compitition.
In other words I think you are solving the wrong problem, and so you have come up with the wrong solution.
Re:Yes, RAID is not the answer (Score:2)
Re:convience for robots. (Score:2)
When I did a co-op stint in IT at a manufacturing plant, we did nightly backups of our servers. It was basically one tape per server. Luckily, we only had about five, so that was five tapes per day. RAID-5 is not an answer, because the tapes were not only in case of disk crash/user error, but also fire, flood or other catastrophe. Our backup tapes were kept at an offsite secure storage location for this reason.
As for users, if they are clumsy enough to delete an important file, they deserve to wait to get it back. Using our system, it could take up to three hours to recover a file from backup tape. It just taught our users to be a little bit more careful.
IBM ADSM now TSM (Tivoli Storage Management) (Score:2)
My boss went to a IBM storage demo in Vegas to see their new tech and one of the IBM guys said in a short time(meaning RSN!), they are going to have a drive that can write 40 TB to one tape! That's COOL!
Yes, RAID is not the answer (Score:1)
This is an important point I hear a lot when discussing backup solutions. "Why don't we just get a RAID array?" Or better yet, "Why don't we just back up to a big disk on another machine?"
Because, as the previous poster mentioned in passing:
RAID-5 is not an answer, because the tapes were not only in case of disk crash/user error, but also fire, flood or other catastrophe. Our backup tapes were kept at an offsite secure storage location for this reason.
If you want real security from your backup solution, it must be physically (and especially electrically) separated from your system. If your RAID array is hit by lightning, a bomb, a tornado, what-ever, you are screwed! But if your backup tapes from last week/month/whenever are in a safe deposit box somewhere, you can restore your data to your new location/machines.
So regardless of the merits of the question about tape size, tape technology is important and should be a topic of discussion among all would be geeks.
Linear Tape Open (Score:1)
Re:What about tape changers? (Score:2)
20% means only about 5 hours or operation per day. Look at your throughput in MB/min and work out how much you can store in 5 hours.
DDS tape changers are meant to reduce the amount of human labour involved in rotating tapes. They are not meant to be used to run DDS drives 100% of the time.
I'd say go for DLT if you are hitting the limits of DDS. DLT is rated at 100% duty cycle. You can run those babies all day and all night without worry.
Later,
Kenn
smaller tapes - easier automated handling (Score:1)
On a related note though, the cost of backups is getting ridiculous. 5 years ago, disk space cost $250/GB and tape media (DDS-2 tape) was $5/GB, so backing up $1000 worth of disk space (4 GB) cost $20. Today, disk space is about $4/GB (75 GB Maxtor drive $300) but tape media (Exabyte Mammoth, AIT, DLT, etc.) is all well over $1/GB, so backing up $1000 worth of disks is going to cost over $250. So tape may be pricing itself out of existence.