Tom Goldberg
Forum Replies Created
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I’d like to thank Michael for the mention, but wanted to correct a misstatement on his part.
[Michael Kammes] “If you’re looking to something dead simple and very robust, you may want to look into Cache-A. It’s LTO5, and while not LTFS,…”
Cache-A most assuredly is LTFS. While we introduced our products with tar archiving before LTFS was available, we were one of the first adopters with a technology showing at NAB2009 and shipping LTFS by NAB2010. Users can choose tar or LTFS format on a tape-by-tape basis and take it to the next level with our cataloging and extended metadata support. We’ll even be showing support for the new Discovery Channel LFTS requirements at NAB2013.
And, while I’m at it, I’d like to correct another misperception that many share with Jim:
[Jim Curtis] “If I understand it correctly, one would be able to mount an LTO tape and have it appear to be a drive, and use the Finder for copying and restoring”
While this statement is true in the strictest sense, those that try this with the free software from IBM or HP, run into serious problems due to the linear nature of tape. When you try to restore many files from an LTFS volume, if you don’t ask for items in the order that they were written to tape, it can literally take days to get all your files back. Products like Cache-A and SDNA presort restore requests among other things to make using LTFS truly practical.
The costs of these products are well below what editors used to pay for video tape decks which is how they used to archive content. I invite readers to check out our white papers for more information about the advantages of using complete solutions rather than attempting to roll your own.
Tom Goldberg
Cache-A Corporation
433 Park Point Drive #285
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
Mark,
I will also respond to your direct inquiry to me, but for the benefit of the community I’d like to share the following.
We have had other customers attempt to use Chronosync with our products and also reported experiencing issues. I am surprised to hear that it could copy files incompletely and not display any errors. That is not the case with Finder – if it completes a copy without errors, we’ve never seen this kind of issue, and if there is a problem, Finder always shows errors (similarly with Windows Explorer).
If for some reason you do not want to use Finder, another way to copy files to a Cache-A is with any FTP utility. This can be faster and also strips off those annoying AppleDouble files that provide little to no utility these days.
If other users out there are having success with different utilities, I encourage you to weigh in here.
Tom Goldberg
Cache-A Corporation
433 Park Point Drive #285
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
Hi Mae,
I’d like to elaborate on the issue and explain what is going on. Almost every LTFS solution is based upon the open source software originally from IBM. We refer to these solutions as a “baseline LTFS deployment.” Such installs allow you to make LTFS tapes pretty well and restore individual files easily, but as you discovered, they do not presort restore lists for order on tape. Thus restores of large numbers of files if not requested in exactly the right order, can cause tape drives to thrash for hours or even days to find all the files. You should also be aware that unless you know which folder to look in, it is very difficult to search for files in any large file tree as tapes do not access like hard disk and are not indexed for searching.
A number of 3rd party manufacturers, Bru included, provide LTFS solutions with their products to permit interchange, but have done little to improve on that baseline functionality. Other 3rd party manufacturers including Cache-A and SDNA know were files are on tape and do pre-build restore lists for efficient recovery of any list of files. Our solution goes further to include metadata and checksums in a searchable table of contents that makes LTFS both practical and extends the functionality. If you would like to learn more about both LTFS and how 3rd parties have enhanced it, I recommend our LTFS white paper available here.
Tom Goldberg
Cache-A Corporation
602 Park Point Drive
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
While technically possible, we don’t offer an upgrade for this model and don’t recommend it for disk capacity, cooling, power and performance reasons.
We do offer Pro-Cache4 to LTO-5 upgrades and Pro-Cache5 to LTO-6 upgrades.
Tom Goldberg
Cache-A Corporation
602 Park Point Drive
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
Hi Gerald,
The question I would ask is, where are you looking at those file sizes? You’re probably checking the source in Finder and using the Mac’s reporting and then comparing them to what the Cache-A reports in the File Manager. Unfortunately, as we’ve had posted on our FAQ page for years, that won’t work:
My archive session shows a different total number of bytes than my computer – is something wrong?
As long as your Transfer Summary shows no errors, everything should be fine. Any difference in reported sizes is caused by variations in the way different file systems and operating systems keep track of file sizes.
In the Mac environment, things changed in this regard substantially with the advent of OS 10.6 – according to MacWorld:
“There are, believe it or not, now two sets of entirely different terms for these two ways of thinking. For example, a gigabyte, or GB, is now defined as 1,000 bytes cubed, or 1,000,000,000 bytes. A gibibyte, or GiB, is equal to 1024 bytes cubed, or 1,073,741,824 bytes. (The same rules apply for megabyte and mebibyte, which are defined as 1000 bytes squared and 1,024 bytes squared, respectively.)
Wake up, you in back! Because here’s where Snow Leopard comes in. In previous versions of Mac OS X, Apple used the1024^3 definition of GB. Rather than keep that math and start calling it GiB, Apple has started using the 1000^3 definition.” [click here for more details]
Even without this change in how sizes are calculated (i.e. a Mac running Tiger or a PC), there are still variations in how file sizes are calculated and you will most likely never see exactly the same number of bytes in both places.
If your files all transferred without errors, you should be able to ignore these reporting differences.
Tom Goldberg
Cache-A Corporation
602 Park Point Drive
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
Good to know that you’ve figured it out Aaron. We caution against using special characters in file and folder names for a variety of reasons, but generally handle them. We will check into this particular case going forward.
Please feel free to contact Cache-A support directly the next time you have any issues.
Tom Goldberg
Cache-A Corporation
602 Park Point Drive
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
Hi Aaron,
Originally you stated that you had “all of my projects in folders on the RAID tht’s attached to my Mac Pro” but what you’ve shown here are the permissions for folders already on the Cache-A share.
If you use our File Manager interface and drag and drop one or more of these folders to the current tape and nothing happens, something is clearly wrong. You might try resetting the Tape Manager (under System Tools > Utilities) and see if that fixes it. Otherwise, we’d have to do a support connect session and look into it further.
If you are doing something different and nothing happens, please describe your steps in detail.
Tom Goldberg
Cache-A Corporation
602 Park Point Drive
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
Hi Aaron,
Your problem with the eSATA is most likely due to the fact that we don’t support Hot Swap for that connection. You should power down the Cache-A, connect the eSATA device, power it on, then boot up the Cache-A. Give that a shot and if it doesn’t solve that issue, let us know.
If you are having problems with just specific folders, it is most likely a permissions issue – use Finder’s get info to open them up or follow the instructions in our Tech Brief here to do that from Terminal.
Good Luck!
Tom Goldberg
Cache-A Corporation
602 Park Point Drive
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
Hi Aaron,
Sorry for a slow response on this query – I missed seeing it. Normally when you have a problem like this, please contact Cache-A support directly as outlined on our support page and we can help you sort out the issue.
Just as an FYI for the community – we have many warnings to not rename the VTAPE from Finder. If you do, simply eject the tape, remove the folder you created, and then reinsert the tape, everything should start working normally again. If this doesn’t work, you may need to restart the tape manager under System Tools > Utilities and repeat the eject/reinsert.
Tom Goldberg
Cache-A Corporation
602 Park Point Drive
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
Hi Kyle,
For spanning to work, CatDV would need to support Cache-A’s concept of incremental tape naming (each tape in a set automatically gets the name of the initial tape followed by _2, _3, …) and a single table of contents (TOC) for a multiple tape set.
While CatDV may implement this in their plugin at some point in the future, there are many reasons why spanning is to be avoided for good archiving practice.
As long as content will fit on a tape, you are much better off creating a new independent tape when the current one becomes full. This keeps each tape with it’s own TOC as a separate entity, is easily duplicated and not dependent on keeping several tapes together for full data integrity.
Spanned tapes rely on all of the tapes in the set remaining together with only the last tape knowing what is on all the others. This means that your archive is at risk if you have serious archiving errors while making a later tape. For this reason, we recommend keeping spanned tapes to 2-3 tapes at most if possible.
Spanning may make sense if you are packaging up data for a specific purpose and want to keep the data together, and is mandatory if the data is too large to fit on a single tape. For most purposes, we suggest you just eject and start a new volume – this is why CatDV always shows in the Cache-A dialog what % of space is left.
On the topic of your catalog not showing all your tapes, I’m sure we can get that addressed by contacting our support department. Our catalogs are very robust and any tape not listed can be learned simply by inserting it.
P.S. Spanning is not supported for LTFS yet, but will be in our version v3.1 coming very soon
Tom Goldberg
Cache-A Corporation
602 Park Point Drive
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com