Jerzy Zbyslaw
Forum Replies Created
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Networking isn’t my strong point but if you just need to check the drive without being on the internet you could set a manual address for your network port in your computer to something similar like https://169.254.0.1 and set the subnet mask to 255.255.255.0 for it as well and then connect to it directly with a cable and then you should be able to see the device if you use the ping command to its address 169.254.0.3 so if the packets reach it then you should be able to use whatever diagnostic software you want.
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Have you tried the two free Veeam products I suggested as I have written to and read from my SAS LTO3 using Windows 7 without any “hacks” whatsoever?
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Unfortunately, I have no idea what is wrong with the drive and at this point I can only suggest that you first post your last reply on the public IBM forum and see if someone else can diagnose the issue https://www.ibm.com/developerworks/community/forums/html/topic?id=1eac1dfe-7eeb-4e9e-8036-fe3668fb54d7 or alternatively contact IBM support directly https://www.ibm.com/support/home/product/5301452/Tape_Drive
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Hello, usually the backup software will tell you as part of the log of data written to the tape as to how many soft and hard errors have occurred and here is an example for Backup Exec https://www.veritas.com/support/en_US/article.100020857 notice that it only has 857 soft errors which is a low amount and can be disregarded.
Since you mentioned that you are using an IBM tape drive then what you should do is download the IBM tape diagnostic tool and see what information you can obtain from that, you can download it here https://www.ibm.com/support/knowledgecenter/en/ST9MBR_1.2.5/ltfs_itdt_download.html
There is always the possibility that there is nothing wrong with the tape drive unit itself and it may be the tape in the cartridge that is the source of the problem especially if it is old and has been re-used many times but this is easy to check because if you then use a new tape cartridge it should store close to the full amount possible so check this as well that your old tapes are not worn out, if the tape heads are the problem then it will store like you said “1.5tb sometimes, 1.2tb sometimes” on both old and new tapes.
Either the tape heads need cleaning and haven’t been cleaned for a while in which case you will need to clean them with a cleaning cartridge or they are going bad and here is a previous discussion with similar problems that you had and it was diagnosed that in that particular case the tape heads were actually bad https://forums.creativecow.net/docs/forums/post.php?forumid=330&postid=654&univpostid=654&pview=t What is the cause with your situation I do not know, it could be any of these problems.
Cheers
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The LTO specification requires that after a write is done then immediately following that the read heads read the data back and check if it is written properly and if not the data is written out again and a “soft error” is recorded and this process can repeat up to 16 TIMES before it gives up and records a “hard error” so the data may be eventually successfully written but there could be a lot of bad writes taking up a lot of space in between and as long as this is <16 then you probably would not notice there’s a problem until you notice that you can only write significantly less data to the tape itself like you mentioned.
I suggest you check the soft error numbers as you could have millions or billions of them and if you do then this usually indicates that you have dirty heads that need cleaning or worn out heads that need replacing, however, since the tape heads reputedly cost around a quarter of the cost of a new tape drive it is not really cost effective to repair it with replacement heads and you may as well buy another tape drive. If this is not the cause of the problem then I don’t know what else it could be as the LTO tapes have servo tracks on them to make sure that the heads are positioned on the actual tape track correctly.
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Unfortunately I don’t know anything about Mac’s so I can’t help you there much although I can make some suggestions.
(a) NTBackup uses the proprietary Microsoft format for storing data on tapes and there are a few other backup programs that also use this format and according to the wikipedia article on NTBackup “When used with tape drives, NTBackup uses the Microsoft Tape Format (MTF),[5] which is also used by BackupAssist and Backup Exec and Veeam Backup & Replication[6] and is compatible with BKF.[7]” but whether any of these also run on Mac’s I don’t have any idea.
(b) The best way to do this is if you have access to a windows 7 machine I’d suggest buying a used LTO4 drive which should be very cheap and installing it in conjunction with a SAS or HBA card as appropriate to run it. Then either download the free Microsoft utility that can restore the data on Windows 7 and Server 2008 R2 machines here https://support.microsoft.com/en-us/help/974674/description-of-the-windows-nt-backup-restore-utility-for-windows-7-and which should work without too many problems, alternatively download the free Veeam Agent for Microsoft Windows program together with the free Backup and Replication 9.5 program as the second one is the program that actually interfaces with tape drives.
(c) If you still want to use the Mac then you could try this tool here but from comments it seems a bit flaky https://www.lightbluetouchpaper.org/2012/06/13/extracting-microsoft-windows-backup-bkf-files-on-mac-os-x/
Cheers
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Its INCREDIBLY EASY if you use the ZFS file system that comes with either Solaris, one of the BSD’s like https://www.freebsd.org/ which are the rock solid ZFS systems, you can also install ZFS On Linux (ZOL) https://zfsonlinux.org/ which should be OK but it’s not regarded as production stable as the first two options.
The reason I say this is that you can create a ZFS file system on either entire disks, or slices (Solaris way of doing partitions) or just plain ORDINARY FILES, see here for an explanation using Solaris https://www.thegeekdiary.com/zfs-tutorials-creating-zfs-pools-and-file-systems/
You then mount the file and access it as you would do a regular disk, so in your case where you said you had a 5TB disk you could for example create say a 2.45 TB file and mount it, you then copy data to it until full and then you unmount it, you then copy the 2.45 TB file to a 2.50 TB LTO6 tape in your tape drive using regular unix TAR, DD, or CPIO commands and then post the LTO6 tape in the mail (it doesn’t only have to be an LTO tape as it could just as easily be an RDX cartridge)
The recipient at the other end just has to reverse the process by loading the tape into their drive and copying the monolithic file to their hard drive or raid array and simply mount it (obviously using ZFS as well, and preferably using the same version of ZFS) and then they can easily access the data.
Because you are creating ZFS using files and not disks or partitions and therefore you don’t have to worry about passing through disk accesses through to the VM itself (e.g. fiddling with VM and BIOS settings for LSI SAS cards and SAS drives) then the easiest way to do this using your existing computer would be to get a free hypervisor like https://www.virtualbox.org/ which runs on “Windows, Linux, Macintosh, and Solaris hosts” or you could use Hyper-V with Windows and I think the Mac has https://www.parallels.com/ available and simply install one of those three ZFS capable systems although to use Solaris professionally it would have to be licensed whereas the BSD’s and ZOL would be entirely free, you don’t have to have a 2.5TB VM as you can just set aside say 50GB for the VM’s operating system and just give that VM network access to let it create a 2.45TB file somewhere else on the computer, network or NAS, once your running the VM and in there you mount the file, then copy 2.45TB’s worth of data from somewhere else to that filesystem (the 2.45 TB file), unmount the file and shutdown and exit the VM.
So to answer your question “Is this feasible on any software?” yes it can and it can even be totally free but the only downside is that suddenly you have to learn one of either unix, Solaris, linux, or FreeBSD but this would be a very good investment for yourself now and in the future especially as data storage sizes are set to explode with 4K and 8K coming in, another benefit is that with ZFS each block in the filesystem if fully checksummed so if it gets sent to the destination and has any errors you’ll know about it if you do a Zpool Scrub command on the entire filesystem, more introductory information about ZFS is here https://pdfs.semanticscholar.org/presentation/bba6/a91ab9573e4284d041b0ae1c41f737d8cb96.pdf and it is far better than Windows NTFS, Linux’s Ext4 and the Mac’s APFS.
Lastly, a second answer to your question is if you don’t want to use ZFS you could just as easily create a 2.45 TB VM file using whatever hypervisor you want containing say an OS of your choosing and as an example together with say a free version of Blender and the Blender files you are working on and then you shut the VM down and then send that actual VM file (together with any relevant config files) and just send all that on the LTO tape, the recipient just has to import the VM into their hypervisor and fire it up. e.g. this article here https://www.techrepublic.com/article/how-to-move-virtualbox-vms-from-one-drive-to-another/ and although this is just as do-able you miss out on the integrity features that ZFS provides and so isn’t my preferred recommendation but this would suffice for say an interim period until you get up to speed with ZFS.
I think the ZFS file and VM image is the only real neat and tidy way to virtualize file systems as these can be any size whereas actual disk images are usually for set sizes (unless you just create a primary partition that doesn’t fill the entire disk) and also contain pesky information like MBR and GPT partition table information that you also have to deal with when transferring which makes actual disk images a bit messier to deal with.
Cheers
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[Neil Sadwelkar] “So, these 44 to 136 end-to-end passes are only one of the 200 to 364 full passes? Meaning the tape life is actually 44×200=8,800 end-to-end passes.”
Correct, the number of end to end passes depends upon how many heads there are and for a lower number of heads more end to end passes are required leading to a tape life of say 200 uses and if they are high requiring less passes this can be say 250 uses and here is an old chart that gives you some idea of this https://www.high-rely.com/blog/advantages-of-removable-drive-vs-tape/attachment/tapelife/
Having said that, out of a theoretical 200/250 uses its generally recommended that the tapes be used only a quarter of this amount say 50/62 times after which I presume they start wearing out and the rewrites start which appear as “soft write errors” and in addition to your “second copy” up to a total of 16 rewrites can be done before this now becomes a “hard write error”, the LTO standard sets aside 5% of every tapes capacity just for these expected re-writes and I presume if you exceed this 5% allocation (which most of the time you probably don’t) your tape run will start asking for ever increasing numbers of tapes to complete the same sized job.
LTO6 should take 5:30 to do a full tape and LTO7 should take 5:55 so if you need 14 hours then perhaps your not feeding it fast enough? I think BRU uses a 15% overhead so 5.1 TB would be a gross 5.9 TB and dividing by 14 hours gives a measly 117 MB/s (5900000/14/3600) which is the typical max speed of a 1Gbe network. LTO6 should be able to do 160 MB’s and LTO7 should do 300 MB’s, compression (probably unlikely for your source data) would give even higher figures.
I’d be inclined to buy a second set of tapes and just write out a second backup set, sure your capital costs would be higher for a second set of tapes but if you skip the verify step on both they will each last twice as long so your consumption costs (due to wear out and discarding tapes) would still be the same but at least you would have two copies of the data.
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[Tim Jones] “And here’s a shot of some LTO-2, LTO-4, and DAT tapes that are over 10 years old and restore perfectly just sitting on the shelf in the closet in our video room”
Shouldn’t these be stored in the vertical position as advised by the manufacturers e.g.
Page 3 of this Quantum document “Keep cartridges in protective case and store vertically when not in use.”
https://storageconsortium.de/content/sites/default/files/downloads/TAPE_best_practises_1.PDF
and Page 28 of this Fujifilm document “Store cartridges vertically (reel axis horizontal)”
https://tapepower.fujifilmrmd.com/Shared/PDF/knowledgebase/LTO_Tech%20%26%20C%26H_2015.pdf
otherwise I presume with either rough handling or dropping the cartridge in a flat position that its possible to have something like that described on pages 32 and 33 where you can have popped out strands or edge damage and I wonder how badly this affects restoration of the data given its “linear tape” that needs perfect alignment at all times to restore data?
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[Ian Henderson] ” in storage for potentially a year or 2 before transfer to LTO (7)”
Since its only a year or two then it probably won’t matter but if its going to be much longer then I suggest you exclusively use BaFe tapes (Barrium Ferrite) rather than the standard MP (Metal particle) ones as LTO6 can use either and the cost difference is minor, LTO7 and up is BaFe only. Kindly read the white paper that explains its advantages over the previous MP tapes.