[Tom Goldberg]

Sorry Jessey, Cache-A’s don’t work like that. Each Pro-Cache is a complete Linux server and wants to talk to its own drives – so there is no way to connect two units to do what you want.

If you’re running v3.x software, you’ve got the Simul-copy feature which will make safety copies just as you want, but you do absolutely need an external drive connected to the SAS port on the back of the Pro-Cache in order to take advantage of that. The sidecar part of this is easy – any powered SAS connected HP LTO drive will work (i.e. an LTO-6 sidecar was an HP Ultrium 6250 External Tape Drive).

The challenge may be getting the Pro-Cache to see it – you may have to go to ProMax and get them to enable the license for a second drive and they may want to sell you the drive to make that happen. OTH, we weren’t that careful about licensing so one or both of your Pro-Caches may just work when you plug in another drive. I’d recommend borrowing a drive from someone and trying it (any LTO-4, 5 or 6 will let you see if the Pro-Cache sees it). If it does see it, a drive selector will appear on your File Manager page.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Tom Goldberg]

Tim’s points about archiving to the cloud and how long it takes to transfer large amounts of data are very valid, but maybe you have the time and/or bandwidth. Not only are transfer speeds an issue, cost is exorbitant as soon as you start to consider how much data you’d want to keep.

Take Amazon Glacier, which sounds cheap at only 1¢/GB. Well, that’s per month, so look at the cost of storing just one LTO-6 tape’s worth of data for just one year: 2.5TB = 2500GB x .01 x 12 = $300 (that’s almost 10x the cost of a tape that’s good for 30 years)

If you really have much data to store for any length of time, these numbers really argue in favor of investing in an LTO based solution.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Tom Goldberg]

Several years ago, my former company (Cache-A) commissioned a white paper on recommendations for long term storage from a well known storage engineer. In particular it describes the potential hazards of long term storage on hard disk drives. The paper is now 4 years old, but the information is still valid. I thought I would post a link to it here for anyone on the Cow’s information: Protecting Digital Assets for the Long Term.

I agree with Tim that your triple redundancy approach is very smart and should keep you covered if you remain diligent. That said, we had many customers over the years who encountered a much higher level of disk drive failures than it sounds like you are seeing, and many of them were not so careful to keep multiple copies.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Tom Goldberg]

All of the tape drive manufacturer LTFS solutions, regardless of vendor, are based upon the original code created by IBM in 2009 when they first promoted the standard and as updated over the intervening years. HP, Quantum and Tanberg all have issued their own versions of freeware or bundleware with their own products, but it all appears to present challenges when used in the real world by real users.

Almost all 3rd Parties who have implemented LTFS have built upon this same code base but have addressed most of the pitfalls users have encountered with the baseline LTFS code. And, of course, those third parties rightly want to charge for their efforts and for providing support, so with LTFS, you get what you pay for.

The benefit of LTFS in my opinion is interchange. Any LTFS tape made on this code base (and some not from this code base – SGL for one) can be read and added to by any other (we did not test all of them, but never had a failure exchanging valid LTFS volumes).

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Tom Goldberg]

Hi Enrique,

What LTFS utility are you using that is giving you such grief?

There are many LTFS solutions that do not have problems copying hidden Mac files (including .DS_Store files) to LTFS volumes. When you start to look for alternate solutions, I recommend you consider one of the third party applications that overcome limitations of the open source free LTFS applications you can download from the tape drive manufacturers. PreRollPost and YoYotta are Mac based applications that probably address this issue and I can assure you that Cache-A appliances will not choke on such files.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Tom Goldberg]

Sorry for the confusion,

Yes – use “[default]” exactly as it appears

The vertical bar is called a “pipe” sign in Linux/Unix (and Mac) and is typed with the shift-backslash on a mac keyboard

You can actually copy and paste the commands from my post to do this most easily.

Good Luck!

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Tom Goldberg]

Hi Stanton,

This problem may or may not be the one documented in the user manual – did you try that solution? If not, let me know, there may be other things to try.

User Manual on Error -50:

Macintosh issues with the LTFS Volume:
Mac OS versions may have issues with what they refer to as “named streams” when dropping folders onto the LTFS Volume and cause the Mac Finder to report an “Error -50” upon dropping content onto the LTFS Volume. If you see this error, you can eliminate it by following the steps in the Apple Knowledge Base report covering this topic:

To disable named streams as a default for all Mac OS X client user accounts on a Mac
Log in to Mac OS X with an admin user account if you aren’t already logged in as an admin, then execute these two commands in Terminal:

echo “[default]” | sudo tee -a /etc/nsmb.conf

echo “streams=no” | sudo tee -a /etc/nsmb.conf

Note that if it was mounted, you will have to unmount and remount the Cache-A share after applying these terminal commands.
For more information about this issue and other options for dealing with it, please refer to the information posted at https://support.apple.com/kb/HT4017 on the Apple web site.
This issue can also be avoided by mounting a Macintosh share on the Cache-A appliance with the Mount Manager facility, and using the File Manager in the web user interface for your operations.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Tom Goldberg]

That’s really too bad Mateusz – it sounds like just those files are damaged and were most likely bad on the source device or corrupted during the transfer to the tape drive. IMO, it is unlikely that they are bad due to LTFS or LTO issues.

Unfortunately I have no suggestions other than possibly data recovery services* – maybe Tim has a better idea.

Articles about 2 LTO data recovery experts:
https://www.storagenewsletter.com/rubriques/tapes/data-recovery-services-corrupted-lto-media/
https://www.storagenewsletter.com/rubriques/security/kroll-ontrack-perform-data-recovery-services-for-software-defined-storage-data-loss/

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Tom Goldberg]

A little touchy Tim? No poo-pooing here, I thought I was being complementary.

[Tom Goldberg] “Archiware and Bru are also excellent solutions”

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net

[Tom Goldberg]

[Tim Jones] “[LTFS is] unpredictable at best, fails when you need it most at worst, and no one provides a responsible level of support” True that you won’t get much support from HP for their freeware but…

I’m pretty sure that there are many who would not agree with this statement – like for instance, the Discovery Network who has standardized on LFTS for their submission format. Or, any of the many vendors who build LTFS into their products and provide their own support services (including the likes of YoYotta, Imagine’s Pre-Roll Post, ProMAX Cache-A, StorageDNA, XenData, SGL, and no doubt others). Not only have these vendors and Discovery found it to be reliable, but it is also proving to be an effective interchange standard allowing any of these companies to read their competitor’s tapes.

Tom Goldberg
TGCS
30201 Rainbow Hill Rd.
Evergreen, CO 80439
mailto:tomgoldberg@gmail.com
https://tomgoldberg.net