[Jeff Schaap]

[Rolf Howarth] “it seems that the request to restore files might sometimes not return as quickly as we thought, so we may need to increase an internal timeout value to prevent errors when issuing the restore command.”

YES. This happened to us the yesterday. We called for a restore and Cache-A restored everything to the vtape perfectly but after we got a timeout error message for CatDV and nothing was restored to our SAN. We repeated the request with the plugin and then CatDV pulled everything from the vtape without issue.

[Rolf Howarth] “. If the Cache-A volume goes offline while using CatDV that CatDV might in some situations then create a folder on your local drive called /Volumes/Cache-A , which means that when the Cache-A is next mounted it will get the name /Volumes/Cache-A-1.”

Yes again. We just found out this happened to us. We’ve had one station that was using the CatDV plugin fine and the all of a sudden would not archive files any longer. Every time we tried it would say “Unable to create directory [target directory]”. We just went and checked and sure enough the phantom folder was there. I think Nathan was getting this same error.

[Rolf Howarth] “Regarding not being able to archive to a tape, eject it, load it again, and add more files to it I’m not aware of anything in CatDV that would stop that working, so that may be a Cache-A issue. Can you add more files to an existing tape if you use drag and drop from the Finder (or Explorer)?”

We haven’t up to this point. When dropping stuff directly into the Cache-A (without the CatDV plugin) we have only done it in single sessions. But I will try a multi-session (ejecting the tape in between write sessions) and see what I get.

Rolf, is there a difference between a software update from Cache-A and the firmware update you are talking about? Tom, how do we know if we have the latest Cache-A firmware (we have software version 2.1.15)? How do we request a firmware update if we need it? We bought our Cache-A in July 2010.

Rolf and Tom thank you so much for dialoging with us about these issues.

Jeff

[Jeff Schaap]

Hey All,

I just wanted to post an update after we did more tests today.

Here’s what we did:

1) With CatDV Cache-A plugin wrote a catalog of 91 files (30 GB) to an LTO tape. No logged errors or other problems.

2) We ejected this tape and cleared the vtape.

3) Re-inserted the tape and then restored the files with the CatDV Cache-A plugin. PROBLEM. Six files were 1/2 or less of their original size. CatDV could not play them. Couldn’t play them in the OS. They are incomplete and / or corrupt. BLARG.

4) We compared the problem files (now on our SAN) against the files on the vtape. THE FILES ON THE VTAPE WERE FINE… wow. So the problem came when CatDV Cache-A plugin copied them from the vtape back to the SAN… WHY?? That seems like a relatively simple operation.

5) We deleted the problematic files from the SAN and the vtape and then called for a restore of just these files through the CatDV Cache-A plugin. They came back from the LTO to the vtape to the SAN without any issue. We are perplexed.

6) We started over… we deleted all the files from this catalog on the SAN and the Vtape. With the CatDV Cache-A plugin we called for a restore of all the files. They were all pulled from the LTO tape to the vtape to the SAN without any issue… HEAD SCRATCHING ENSUES. Why did this not work the first time and now it was flawless?

We move on to seeing if we can write multiple sessions to the SAME tape (NOT spanning tapes). It works only if you NEVER EJECT THE TAPE. If you do eject the tape and then try to write more files to tape in a later session it will overwrite whatever is on the tape… so that means you have to fill the tape (if you want your money’s worth) without ever ejecting it.

My question is, is that normal operation or is this some sort of problem with CatDV Cache-A plugin? Any thoughts Tom?

[Jeff Schaap]

Ok… we are SO confused.

We just did a test and CatDV Cache-A WAS able to recall files from the LTO tape… we deleted the VTape, called for a restore and watched the Cache-A seek up to the files, copy them to the Vtape and then CatDV Cache-A plug-in copied them to our SAN. So, Tom, it seems that this is working after all?

However, some of the footage we wrote to the tapes is missing… LARGE portions and we don’t understand why. We wrote in two sessions and only some of the footage from the FIRST session is on the tape.

Tom, can we not write multiple sessions to the same LTO? That poses a big problem if it’s true.

Jeff

[Jeff Schaap]

Wow… thank you Tom for the information, especially about the end user needing to restore the files to the Vtape first… our integrator never told us this and all our frustrations now make sense. This is the reason why we can’t get anything to restore properly. In all the demo’s we saw of the plug-in the tape was never ejected so the files never left the Vtape… they were just getting recalled from the Vtape when the plug-in called for a restore. That must be why it worked in those demo. settings but not in our “real-world” tests. No wonder the plug-in is saying things like “Can’t restore from VTape” while I bang my head on the wall and say “It’s on the LTO!”

The information about not using spanned volumes in CatDV is also helpful. Again, I wish we had understood that at the outset so we wouldn’t have wasted hours trying to figure out why it wasn’t working.

I guess this is why they say information is power… sigh.

Thank again Tom,
Jeff

[Jeff Schaap]

Lindsay,

We are using the CatDV plug-in exclusively, what you are calling the “Archive Media Files” tool. This only appears in CatDV if you have the plug-in. It didn’t for us until our licenses came through.

We have to do it this way because we need CatDV to remember which LTO tape a given video clip was cataloged too.

I had a thought on your issue with it working when you drag and drop from Staging to VTape but not when you COPY from Staging to the VTape.

I know that as soon as you drop anything in the Vtape directory Cache-A takes off writing it immediately to tape. Just like a CD-writing session if the writing device (the LTO writer in this case) gets “starved” for data it will create an error (a buffer under-run). I wonder if that is what’s happening… Cache-A starts writing but “catches up” to the copying and gets starved for data.

Early on, when we were using Cache-A outside of CatDV to create backups the people at Cache-A were telling our tech. to copy everything to a “Staging” folder first (seems like they are telling you that too) and then once everything was there, drag and drop it into Vtape. Their reasoning was that if you copy across a network directly into the Vtape folder the Cache-A might get starved for data at some point (like when copying a large file) and cause an error.

However, this doesn’t work for our situation. First problem: we have to work with the plug-in as I mentioned. Second: we can’t tell the plug-in to write to the staging folder because that is non-unique name… if all our footage was written to “staging” (as far as CatDV knows) then it is going to try to restore from “staging” instead of the LTO tape’s serial number. So, we MUST write across the network to the Vtape and the plug-in intends for it to work this way. When you start the archiving process you can “see” Cache-A writing the clips from the catalog into the Vtape folder but the serial number of the tape gets recorded in CatDV.

At first we had our Cache-A passing through a 10/100 network and we were getting buffer under-run issues (I think… we were getting errors anyway). However, now we have a gigabit network and we can write with the Cache-A plug-in to the Vtape (through the plug-in) directly without any trouble at all- we never have errors. We’re just working on the recall issues.

So what is your network speed?

We are going to get this to work! 🙂

Jeff

[Jeff Schaap]

Hey Lindsay,

Yeah, I hate to be a pessimist but I have yet to bump into anyone who is using this successfully. I have had integrators demonstrate it to me by writing a couple files and bringing them back but that is a far cry from backing up and recalling thousands of files without issues.

We aren’t having any issues on the transfer or errors during Cache-A writing. It’s recall that’s the issue for us right now. We did discover today that you have to OPEN the catalog and then do the backup in order to retain the information in the “Archived Status” field. If you are in read-only server mode it will show the tape name and such that the clip was archived too but the info. will be lost if you restart CatDV and no other client will see those changes (because they are not actually saved). So, you have to open the catalog, send to to Cache through the plug-in and then save the catalog.

Strangely, we have discovered that when we don’t do that CatDV STILL knows where the clip was saved (but doesn’t display it in the “Archived Status field)… If you select a clip that has nothing in the “Archive Status” and then go Tools > Archive Status it reports the tape name where it’s located! Figure that one out.

I was also going to mention to you and Nathan to watch out for illegal characters in filenames… we are in a Mac environment and anything that had non-alphanumeric characters gave us errors. And unfortunately, we had a ton of those files. Those files would trip the creation of “Apple Double” files and they took up a LOT of space. We eventually got this mostly resolved with CatDV. I am wondering if you and Nathan are getting the same type of problem on the PC side… since you both get seemingly random errors. Could it be filename issues?

To answer your question about file formats we have quite a variety… We have some stuff prior to when I was here shot on Panasonic P2 format but that has mostly been dropped to ProRes. We now shoot AVCHD footage generated from our Sony NEX VG-10’s (LOVE this camera).

We did not pay for the MXF plug-in for CatDV because ultimately we decided we didn’t need it. We don’t really have a need but I could create a Worker Node routine to trip ClipWrap and generate ProRes preview files so the clips could be reviewed in CatDV just as we do with our AVCHD files. But we just haven’t had call for it yet since most our stuff was “log and transferred” by FCP 7 into ProRes and the MXF files are long gone. We have a ton of other stuff that is mostly .MP4 or some flavor of Quicktime. But, we haven’t had any particular issue with Cache-A or CatDV not wanting to back up a certain type of video… which I think was the point of your question.

We are doing more testing today. I will share anything I think that is useful to you, Nathan, or anyone else interested. Let’s keep talking.

Thanks,
Jeff

[Jeff Schaap]

Scott,

When we enabled multi-volume and Cache-A did ask for another tape (through the web interface) when the first was full. However, we have not successfully recovered files from a spanned set. In fact, the Cache-A plug-in for CatDV doesn’t seem to be performing reliably at all and we aren’t using it or the Cache-A at this point. I can’t detail everything we’ve tried but basically, it doesn’t work. We get conflicting stories from our integrator, CatDV and Cache-A about whether or not we can use spanning. It’s been very frustrating because we can’t get a straight answer out of anyone.

Right now I have a technician dedicated to getting it figured out. I personally can’t spend more time on it as we have actual projects to get done. I would be happy to update you on our progress and what we discover. If you don’t hear from me in a while give me a nudge and I will update you here.

Thanks,
Jeff

[Jeff Schaap]

Yes, ClipWrap will rewrap (and even transcode) .MTS files from the VG10 (and FS100 I assume) with a GUI or via command line. I had to talk to the makers of the software to get the correct syntax as their documentation wasn’t correct.

[Jeff Schaap]

Yeah, we were glad to find out it was command-line addressable too. I had said earlier that ClipWrap was free but I was wrong on that- it is about $50. Far cheaper than other encoding solutions anyhow.

The other thing I did not mention is that we use another watch action to find the ProRes renders from ClipWrap and crush them down to H.264 MP4’s Then it throws out the ProRes previews. This take a ProRes file from 750 MB down to one that is about 40 MB. Saves us a lot of space. The ProRes previews are available pretty quickly and can be logged / reviewed while Worker Node crunches them down to H.264.

Jeff

[Jeff Schaap]

Whoops… figured it out. The material was still on the Cache-A “VTape” and thus the reason CatDV / Cache-A was refusing to rewrite it. We deleted the material on the VTape through the Cache-A interface and then were able to start the backup again.

Jeff