Tim Jones
Forum Replies Created
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Hi Rumen,
No apologies required :).
The link to the L&TT can be found by going to https://www.hp.com and searching for “L&TT for OS X”.
The Areca issue is a combination of both their chipset and the OS X driver because the chipset is not configured to handle large, contiguous block reads and writes that occur when using tape. When you transfer data to a disk, the data blocks are broken up into what are called scatter-gather segment – each segment usually the size of a disk block or small multiple of the disk block – and written through the filesystem’s IO manager. Tape, on the other hand, requires large contiguous blocks for proper I/O operations (we actually recommend 1024k for LTO-4). The fact that you’ve been successful using tape with the Areca HBA to this point is a serious stroke of luck.
To explain how BRU works with the tape for determining capacity – a tape drive always knows where it is while writing to a tape. As we get close to the end of the tape, the drive sends us an “Early Warning – End of Tape” (EWEOT) status. We don’t control that, but once we receive that status, we write the current block and then write the end of volume marker to tell the BRU restore process that there is another tape and then continue to the next tape. This is why I indicated that I suspect a drive issue in causing your short writes – the drive decides when it’s written all that it can write, not BRU.
The L&TT diagnostic tool from HP is how we can determine what’s going on with the drive.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
That explains a lot.
First, the Areca HBAs / drivers don’t properly support tape. I’ve totally surprised that you’ve had any success at this point. The only pSCSI HBA that we had success with back in the day were the ATTO UL4 and UL5 cards.
Next, run a cleaning cartridge in the drive.
Finally, go to the HP website and search for “L&TT for Mac OS X”.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
HI Rumen,
The compression in LTO drives is automatic. It’s also lossless, so you get back exactly what you put in. There is no further compression in your situation because the data is already compressed by either your camera or your CODEC during transcode.
As for capacity, BRU does incur around 18% overhead to provide the reliability factors that are included in its container format, but loss of 300GB is 38%, so something is going on at the drive level. A couple of questions:
When was the last time you ran a cleaning cartridge through the drive?
Have you downloaded HP’s Library and Tape Tools and run a diagnostic test on the drive?
(depending on the number of tapes you’ve used, the drive may be exhibiting head wear with will reduce tape capacity).
What version of OS X are you using and which pSCSI host bus adapter are you using?Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
Seth,
What vendor’s drives are you using? Also, how are they connected (which SAS HBA, which driver version)?
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
Hi Robert,
No firm news yet. We’re hoping that we’ll have initial engineering samples before Christmas. If all goes well, that means first customer shipments in Fall of 2016. However, engineering samples and finished product are two very different creatures, so I may be completely wrong ;).
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
What you’re seeing is mainly related to the slower CPU speed and lower performance Nvidia GPU on the rMBP. I have Thunderbolt attached RAID-0 SSDs as my working environment (over 800MB/sec sustainable I/O) and my rMBP still does this (and it’s also a fully loaded i7 unit).
For now, get yourself a good coffee maker and enjoy a fresh cup any time your need to render effects / transitions / etc. …
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
I agree with Noah. Since the 10.2 update, it seems that the background operations can really saturate the rMBP. I’ve just learned to let it go until the background (or not-so-background) tasks complete.
I’ve even found this to be true on built-in Motion transitions and generators.
But, as Noah also said, these issues disappear on my Mac Pro.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
Use the “Clip Appearance” button down next to the Zoom slider:
The second option gives you the best balance between the video and audio waveforms.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
Make sure the destination drive is formatted as HFS+ and not one of the MS_DOS oriented formats. I’ve seen that where you tried to copy a file onto an MS_DOS centric filesystem and it failed due to the source file size.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
Your Fat32 drives should be properly recognized and mounted on your modern Mac OS X system to the point that you can simply drag and drop your folders rom the old drives to the new volumes. We transfer files using this method all the time.
What errors are you running into specifically?
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters!
