Correct me if I'm wrong but it seems that we are crunching through work that has been previously done.

For example the following days a either being split or in the splitter queue. And according to calendar from the old seti site these days have already been distributed. I understand that this might be due to multiple tapes for a particular day (i.e. aa, ab, ac, etc) but this seems pretty unlikely to me.

Seti Calendar

28ja00aa
24ja00ab
16oc99aa
18oc99aa
16ja00aa
09no00aa
21ja01aa

Any thoughts?

-AdRoc

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Correct me if I'm wrong but it seems that we are crunching through work that has been previously done.

For example the following days a either being split or in the splitter queue. And according to calendar from the old seti site these days have already been distributed. I understand that this might be due to multiple tapes for a particular day (i.e. aa, ab, ac, etc) but this seems pretty unlikely to me.

Seti Calendar

28ja00aa
24ja00ab
16oc99aa
18oc99aa
16ja00aa
09no00aa
21ja01aa

Any thoughts?

-AdRoc

Tape usage is totally random. As has been said before, they just reach into a box of tapes and use whatever come up. There is no attempt to use recordings in any kind of order.

Also some of the tape that were put aside because at first look seem to contain mostly noise are being given a second screening and are sometime being used.

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Boinc V7.2.42
Win7 i5 3.33G 4GB, GTX470

Redundancy I believe for this purpose is key to legitimizing the result itself. I believe this is why it is done, also suspect this will happen quite frequently now and in the future. Another reason may be the fact that with the influx of Classic users recently they have been running out of work. And also as Aurora Borealis put it.

Only my speculation here.

Antony Magnus

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Ni newly returned, not newly knighted! Ni

Redundancy I believe for this purpose is key to legitimizing the result itself. I believe this is why it is done, also suspect this will happen quite frequently now and in the future. Another reason may be the fact that with the influx of Classic users recently they have been running out of work. And also as Aurora Borealis put it.

Only my speculation here.

Speculation indeed...

Matt L (he whom grabs the tapes outa-da-box) has previously said that they have enough unlooked at tapes to keep everyone busy for a few months still. Certainly long enough to keep us all busy until seti-enhanced gets up and running. We can then look again at the existing data but with far greater sensitivity and slightly greater precision. Matt may rework the 'most interesting bits' first.

We then get various other telescope data sources coming online.

Berkeley's biggest headache at the moment is that:

1: They have run out of tapes for any new data!

2: They are down to their last one working tape drive!!!

Equipment and tape donations welcomed!

Happy crunchin',
Martin

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See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

Some facts:

1. We haven't recorded any new data in about a year.
2. We are now using tapes that have been in the system before, but for some reason or another (broken splitters, database corruption, etc.) they didn't yield very much science, if anything at all. There are about 90 of these tapes. At the current "burn rate" this will last about 6 weeks. With enhanced, a bit longer.
3. We hope to have the new data recorder on line soon.
4. It makes absolutely no scientific difference at all what order we put these tapes into the system. I don't have the time to sort these tapes by date. I'll let the database do all the time sorting for us when all the results are returned.

- Matt

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-- BOINC/SETI@home network/web/science/development person
-- "Any idiot can have a good idea. What is hard is to do it." - Jeanne-Claude

Some facts:

Thanks Matt for the update.

[...]
3. We hope to have the new data recorder on line soon.
[...]

How does the data get back to UCB when the new data recorder gets installed?

Has Arecibo now got a satellite link?!

Thanks,
Martin

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See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

How does the data get back to UCB when the new data recorder gets installed?

Has Arecibo now got a satellite link?!

Nope.. Arecibo still has a slow but adequate connection to the world. So our data will continue to be shipped on DLT tapes, albeit 300GB tapes (as opposed to the current 35GB tapes). There is some discussion about using hard drives instead.

- Matt

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-- BOINC/SETI@home network/web/science/development person
-- "Any idiot can have a good idea. What is hard is to do it." - Jeanne-Claude

I'm pretty sure a few weeks or maybe a month ago someone offered a tape drive that was collecting dust an asked how to get it to Berkeley but I can'nt find the posting.

I remember that too.

http://setiathome.berkeley.edu/forum_thread.php?id=26793#239513

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I think they were dlt40's, but I read that as well.

...There is some discussion about using hard drives instead.

- Matt

Those are cheapest and fast, but also the most fragile!

Copy the data onto multiple drives, pack very carefully for posting, and send the second copies some time later in a second parcel. Pack so that you can confidently kick them down four flights of stairs and prove that they always survive!

Regards,
Martin

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See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

How does the data get back to UCB when the new data recorder gets installed?
Has Arecibo now got a satellite link?!

Nope.. Arecibo still has a slow but adequate connection to the world. So our data will continue to be shipped on DLT tapes, albeit 300GB tapes (as opposed to the current 35GB tapes). There is some discussion about using hard drives instead.- Matt

Matt did you see this thread? http://setiathome.berkeley.edu/forum_thread.php?id=28110
It says that Arecibo has a T3 line now.

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Matt did you see this thread? http://setiathome.berkeley.edu/forum_thread.php?id=28110
It says that Arecibo has a T3 line now.

Right. I think roughly our new data rate would average about 32 Mbits/sec. A T3 could handle that, but.. well, yeah. You do the math.

Wow. I remember my first few years here working on SERENDIP. Back then (around 1997) the connection from Arecibo to the rest of the world was a single 56.6K modem. And I'd ssh over that along with everybody else. Painful.

- Matt

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-- BOINC/SETI@home network/web/science/development person
-- "Any idiot can have a good idea. What is hard is to do it." - Jeanne-Claude

...There is some discussion about using hard drives instead.

- Matt

Those are cheapest and fast, but also the most fragile!

Copy the data onto multiple drives, pack very carefully for posting, and send the second copies some time later in a second parcel. Pack so that you can confidently kick them down four flights of stairs and prove that they always survive!

Regards,
Martin

Multiple copies are a good idea, but a RAID array would be even better. With RAID (Redundant Array of Inexpensive Disks) the data is split onto three or more drives in such a way that if one of the disks were completely destroyed the data could be reconstructed from information stored on the other drives. Of course it takes at least three drives to contain what would be one drive full of data, but the data can be reconstructed on the fly, without waiting for a backup disk that could possibly get damaged too. And if the drives were shipped in individual boxes, the possibility of one of the drives getting misplaced/lost in shipment would not be a factor either. The number of permissible missing disks increases with the number of disks in the array. For example 5 disk arrays could loose two complete disks without error. Also even if the disks were damaged in shipment, there is a good possibility that the damage would not be the same on each disk, so if the disks were readable at all, the information could possibly be reconstructed from the non-damaged portions of each disk.

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Jim

Some people plan their life out and look back at the wealth they've had.
Others live life day by day and look back at the wealth of experiences and enjoyment they've had.

How does the data get back to UCB when the new data recorder gets installed?

Has Arecibo now got a satellite link?!

Nope.. Arecibo still has a slow but adequate connection to the world. So our data will continue to be shipped on DLT tapes, albeit 300GB tapes (as opposed to the current 35GB tapes). There is some discussion about using hard drives instead.

- Matt

How about a "cd" that can hold 100-200 gb! It's called "blueray" and they are supposed to be shipping single layer 25gb/disk systems shortly and a 2 layer disk has already been developed that will hold 50gb/disk. The disks can (in the fairly near future, they say) be increased to 8 layers, each holding 25gb of data for a total of 200gb on one cd/dvd style disk.

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Jim

Some people plan their life out and look back at the wealth they've had.
Others live life day by day and look back at the wealth of experiences and enjoyment they've had.

How about a "cd" that can hold 100-200 gb! It's called "blueray" and they are supposed to be shipping single layer 25gb/disk systems shortly and a 2 layer disk has already been developed that will hold 50gb/disk. The disks can (in the fairly near future, they say) be increased to 8 layers, each holding 25gb of data for a total of 200gb on one cd/dvd style disk.

This might be a good idea even with normal CD/DVD recordables. There would be less room per disk but with proper handling the data would not degrade over time.

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BOINC WIKI

BOINCing since 2002/12/8

How about a "cd" that can hold 100-200 gb! It's called "blueray" and they are supposed to be shipping single layer 25gb/disk systems shortly and a 2 layer disk has already been developed that will hold 50gb/disk. The disks can (in the fairly near future, they say) be increased to 8 layers, each holding 25gb of data for a total of 200gb on one cd/dvd style disk.

This might be a good idea even with normal CD/DVD recordables. There would be less room per disk but with proper handling the data would not degrade over time.

Yes, indeed but we have to buy it then i think.

regards Mike

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With each crime and every kindness we birth our future.