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LTO-7 and Mac Platforms
Hi Folks,
I wanted to provide an update about using LTO-7 tape drives on a Mac or Linux system. As always, my team continuously tests tape technology against all platforms and we have identified a serious data reliability issue if you’re using LTO-7 with a Mac or Linux platform. Regardless of the software that you use – BRU, Retrospect, or an LTFS-dependent solution, the only HBA / Thunderbolt solution that is working properly is the HighPoint Technologies RocketRAID 4522 or their RocketSTOR 6328 with the 1.8.11.1 firmware. Any other SAS HBA / Thunderbolt solution will result in serious speed issues (at best) and randomized, unrecoverable read errors from the tape (at worst).
In addition to the resolution that HighPoint has provided, we are working with ATTO to help identify and resolve the issue with their H680 and R680 HBAs, but we don’t have an update or ETA for a resolution.
At the present time, there is no chance for a resolution with the ARECA or generic LSI SAS HBAs since they don’t provide proper tape support under OS X.
If you are using an mLogic mTape LTO-6 or LTO-7 Thunderbolt drive, be sure that it is a revision 2 drive (uses the HighPoint HBA internally instead of the ARECA) and that you get the latest firmware and drivers from mLogic for OS X.
If you are currently using LTO-5 or LTO-6 drives, you are okay with either the ATTO or HighPoint solutions. However, if you are looking at using LTO-7 for your backup, archival, or interchange needs, please be sure to only consider HighPoint SAS connectivity until ATTO provides new firmware and drivers to resolve this problem.
If you are currently using TOLIS Group’s ArGest tape solutions with the HighPoint RR4522 or RS6328, please open a support ticket at support.bru.com for information on how to download and apply this latest firmware and driver to your system.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
24 Replies
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You’re saying that LTO7 on MAC’s and Linux are all having speed issues, is there a specific version level of MAC OS or Linux that you’re seeing a decrease in speed?
I frequently test IBM, HPE, and MagStor tape drives with PreRollPost, YoYotta, and the basic HPE StoreOpen software, and haven’t seen any issues, nor have I had any customer complaints. All of my customers use the mentioned software with an ATTO H644, H680 or Thunderlink 2068. Is this just an isolated issue with just BRU?
Tim Gerhard
Magnext
614-433-0011 x114
tgerhard@magnext.com -
[Tim Gerhard] “You’re saying that LTO7 on MAC’s and Linux are all having speed issues …”
Yes – IF you’re not using the HighPoint RocketRAID 4522 or RockstSTOR 6328 with their 1.8.11.1 firmware (and the 4.4.1 IOP driver on Mac).
Are you saying that you’re seeing 300MB/sec+ with the ATTO solutions? Interesting since ATTO can’t even get there. Even with specifically tuned data sets and I/O setups, we’re maxing out in the 220-230MB/sec range. Also, both we and ATTO are witnessing read checksum errors with the R680 specifically (I’ve updated my original post to remove that comment WRT the H680).
[Tim Gerhard] … is there a specific version level of MAC OS or Linux that you’re seeing a decrease in speed?
The version of OS X doesn’t matter – 10.9.5 through 10.12.1, nor does the Mac system type. For Linux, we’ve tested with kernel versions 2.6, 3.X, and 4.X (tape I/O is kernel-dependent, not distribution dependent). Under Windows, we’ve used Windows XP, Server 2008, Server 20012, Windows 7, Windows 8.1, and Windows 10.
It’s not surprising that you’d not witnessed what we’re seeing if you’re only testing with LTFS-based tools. Since LTFS-based solutions such as the ones that you describe don’t manipulate the tape drive directly, they are only aware of issues if the tape layer reports them. Unfortunately, LTFS doesn’t provide the levels of reporting from the tape layer that would truly identify the problems that we are witnessing. They can only report absolute failures or “after the fact” failures based on any form of checksum sidecar that is created (MD5, SHA1, etc.). Because BRU is talking directly to the tape drive at the SCSI / IOP layer with no “middle-man”, we are always aware of the state of the drive through both sense request and Tape Alert calls on our command channel for both write and read operations.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
Hey Tim…
I’m curious if you’ve gotten any farther with your testing. I’m working with a local non-profit to help them set up an LTO-7 archive solution. They purchased a standalone HP LTO-7 Ultrium 15000 tape drive. I have it running on a custom built Windows 10 system through an ATTO H680. I’ve downloaded and installed the latest firmware for both the H680 and the LTO drive, but it’s running slow. Using LTFS and PreRollPost. They have lots of large DPX sequences that they need to archive, and I was thinking the nature of trying to backup tens of thousands files was part of the slow down and beyond that maybe PreRollPost itself was having issues writing that many files, but after reading your post I’m wondering if there’s something else going on. PreRollPost doesn’t give a speed in it’s copy details but just based on the time, it’s taking waaaay too long. And way too long just for the copy step before we even hit the XXhash checkum verification step. For example, we tried a 130GB folder last week, around 11,000 12MB files plus a 125MB sound file and it took over 2 hours for a full copy and verify. Conversely, just dragging and dropping the folder to an LTFS formatted tape in Windows Explorer took about 20 minutes and claimed to be running around 150MB/sec…still way slower than LTO-7 should be able to achieve. I haven’t talked to Imagine yet, and I know that’s my next step, just gathering as much info as I can first and also checking the performance on the Mac build of PreRollPost before I send that email. But I came across this post and wondered if you’d gotten anywhere with your testing in the last few months. Any info you have would be appreciated.
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Hi Luke,
No changes. Right now, only the HighPoint RR 4522 (PCIe) or the RS 6328 (Thunderbolt) options will actually drive the LTO-7 devices at top speeed on a Mac. ATTO has resolved the lost/bad block read issue with the R-series cards, but the speed is still where it is.
And, since PreRoll Post and many others are dependent on LTFS for tape I/O – they don’t actually write to the tape drive – they will only be as robust as the LTFS layer for the vendor’s drive that you are using. We’ve been testing all versions of LTFS along with BRU through all of this and until something changes at the core of LTFS on OS X, you’re going to be stuck with what it is.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
Has this issue been resolved. The speed, or lack of it, I mean, on a Mac with Atto HBAs
I’m about to place money on a Tandberg LTO-7 drive along with an Atto ThunderLink SH 2068 TB2-SAS adapter, (which is suspect is internally an H680). Mainly for its size as this will be a ‘travelling’ setup.
But, since I expect to be backing up Thunderbolt or USB3 RAIDs, a speed cap of 230 MB/sec would be a disadvantage.Which comparable Highpoint HBA would be a better choice? How about a Rocketstor 6328 or 6328L/6324L since I don’t really need the RAID capabilities while driving an LTO-7 drive.
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Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India -
Nope, and according to ATTO it won’t be. They seem to be satisfied with the lower tape speeds. Since you’re buying new, I really recommend the HighPoint RocketSTOR 6328. Do not use the L versions as they are “limited” and don’t support tape. This will give you both hardware RAID and top speed for tape and disk.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
I just came across this page at Yoyotta’s site which bears what Tim said about speed and LTO-7 drives…
https://yoyotta.com/help/installRocketStor.html
To quote…
“The RocketStor does not support the TLR protocol so it is not compatible with the higher speed of LTO-7 drives
If using an LTO-5 or LTO-6 library use firmware v1.8.1.0 as newer firmware v1.8.8.0 will not format and mount tapes.
There are other models like the 6328L, which will not work with LTO drives.”———————————–
Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India -
… unless you’re using a RocketSTOR 6328 or RocketRAID 4522 purchased from TOLIS Group as part of one of our bundles:
bru: [I181] wrote 53680128 blocks (107360256 KBytes) on volume [1], 0:05:34, 321437 KB/sec
That 100GB quick test was a combination of R3D, DPX, and M2TS files located on one of our ArGest RackMOD arrays.
We have developed additional firmware and drivers for our units that does resolve this issue.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters! -
Tim,
are your advices up to date?
I just checked the checksums of my first 5.54TB of data stored on an IBM LTFS LTO7 drive, through an Areca SAS HBA, and not a single bit was corrupted.
Write speed was 230 MB/s (room for improvement, but not horrible for ltfs), read speed was slower than ltfs on LTO6, with only 100MB/s.
So I’ll be looking next at changing the SAS card. The RR4522 you recommend is EOL though; do you know something about the RocketRaid 3740A that you could share?
thanks!Michael Cinquin
Charbon Studio, film finishing and DCP mastering
Post-production tools -
Hi Michael,
Still no change to this status. And, if you’re not having issues with an ARECA card, it is truly luck that is driving your efforts and not technology.
While the RR4522 is reported as EOL, there are still plenty available. We have not had a chance to test the 3740 series as yet. I will post a new thread once we know more.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.tolisgroup.com
BRU … because it’s the RESTORE that matters!
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