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Discussion in 'TiVo Series3 HDTV DVRs' started by bkdtv, Oct 19, 2007.
Partition 11 is not 4k aligned.
I stand (or sit) corrected.
So it looks like any TiVoHD (and perhaps ANY Series 3) upgrade via JMFS or WinMFS to an advanced format drive may/will(?) result in media partitions - the ones we care most about - that are NOT aligned with the 4K sectors of such a drive.
Two questions come to me first:
1) How significantly does this impact performance and longevity of the drive?
Is it worth the worry?
2) Is there a way around it or a preferred way to mitigate it?
For example, doing a DD copy or using a high RPM drive with a long warranty.
A lot of reports of successful upgrades to WD20EURS and other AF drives here, I believe.
Right. And that's what has me scratching my head about whether it's really that big of a deal.
Now, admittedly, I'm still a long way from filling up my drive with it being at only about 50%, but I've been finding the highest bitrate channels and recording them while playing back a third high bitrate recording with skips, FFs, and REWs, all without it seeming to skip a beat.
So what sort of problems should we anticipate if we gloss over alignment issues? Will excessive seeking due to data blocks not being physically aligned with the drive's own alignment be the weak link, causing it to wear out faster? Perhaps as the drive fills to 80% and more and fragmentation becomes more prevalent, the affect will be more obvious.
It'll be interesting to see.
Uh-oh. I have a lineup discrepancy I was trying to correct by resetting it, and it's been stuck in the "(Preparing...)" mode for 20 minutes. This can't be good...
Never mind - it finally resumed progress and is now downloading the info. Still, I don't remember ever having such a long "preparing" step.
Edit: Wow, that took 90 minutes! Has anybody else experienced anything like this after a drive upgrade?
Only TivoHD can use jmfs. Series 3 OLED can't. Apparently jmfs was designed for Premieres, and only happens to work on TivoHD. Some partition differences or something.
I have no technical knowledge on this issue, but I think you're probably worrying over nothing. AFAIK, current drives are WAY faster than a Tivo needs, so there's no reason to care about alignment..
You are only half right.
You can use the GNU DD_Rescue software, that JMFS uses, to CLONE (Copy) ANY drive. It's available on the JMFS CD, as well as many other bootable "Rescue CD/DVD" compilations.
If it (JMFS) won't work in the guided/automated menus (because it looks for a recognizable TiVo partition map before giving you any further options), just drop down to command prompt and do the Copy (clone) from there.
Then, you'd use WinMFS (or maybe the bootable "MFS Live" CD) to finish up the rest. There also was a breakthrough made, where some software called iBored (or something like that) made things possible, that had long been dismissed as impossible to do with a TiVo S3 OLED.
EDIT: Sure, in a TiVo, even the drives that came factory installed, exceeded the performance required. However, there is reason to worry about 4K alignment. In a TiVo, it may not, necessarily, reduce the performance enough to notice, but the misalignment causes excess reads/writes/seeks, which gets worse as fragmentation occurs. This will theoretically shorten the life of the drive, compared to the life span the drive theoretically would have had, had it been aligned. The reason why I have to use the word "theoretically", is that nobody has done anything to prove this, yet. The general life-expectancy of a drive is ~3-5 years, and varies, depending on it's use, abuse, and environmental factors. I don't think that there are too many people, who have had a 4K, misaligned, drive in use long enough to see if the performance drops below acceptable levels, and/or experienced premature drive failure. Just because we use these drives, and they work fine, NOW, doesn't mean they are going to continue on that way, and for the same amount of time as either a true 512 byte sector drive, or a properly aligned/optimized 4K/512e drive. Only time will tell. Until then, "theoretically" is the word...
Well, I'm afraid the honeymoon took a big nosedive in the last 24 hours.
I had recorded the last 9 hours of ESPNHD's Wimbledon coverage into 4 files and spent a lot of time fast-forwarding to segments I wanted to watch. Several times the FF'ing got very kludgy and twice the TiVo became unresponsive and rebooted itself. My conclusion is that the WD20EURS may be just fine for normal playback and skipping commercials, but it's not going to work for all the FF'ing I do.
I'm not sure how to proceed with this, but there's got to be a better option.
I have a Premiere (2-tuner) in the bedroom that I've been wanting to upgrade because it only has a 500 GB drive, but from what I've seen on here it has an OS that is not 4K aware as well, so I'm likely to run into the same problem with any drives that are available today (4K). Does anyone believe I would fare any better with a Premiere upgrade?
I do have a Seagate DB35.3 Certified Repaired 750GB drive that was a warranty replacement for my first failed DB35.3 drive from a couple years ago, but I've been hesitant to put it into service in a TiVo for what would probably be a shorter life than when it was new. However, it might be the only 512 B sector drive I have - and it IS a DVR drive. I would consider popping it into this TiVoHD and deal with reduced capacity so I can have responsiveness, but really only if it's the only way I can get better performance.
I'd gladly settle for merely a 1TB drive like the WD10EVDS I replaced the first failed DB35.3 with, because at least I know it's a 512 byte drive. I just don't have any idea where I'd find one.
Are there any ways we can manually force all Tivo partitions to be 4K aligned on an advanced format drive? It sure seems that Tivo has had to do it on the Premieres they ship with EURS drives. Can GParted do such a thing or are there command line methods for moving unaligned partitions into aligned positions? How does TiVo do it?
Even if you find one it may turn out to be Advanced Format. I wanted to buy another WD10EADS drive because of the good experience I've had with one for almost four years (so far). I was able to buy "new" ones (which did appear to be factory new) but they are now 4K instead of 512. They say "Advanced Format" on the label on the drive case.
I was going to warn him of the same thing. I lucked-out and received factory-recertified 512 byte sector WD20EADS drives, when I standard RMA'd a batch of the same model to WD.
I was going to sell those still-sealed replacements, but now think that they are well worth holding onto. I may even use them for my TiVos, and instead, sell-off the five WD20EURS drives I haven't opened yet.
I only own TiVo HDs and two-tuner model Premieres, neither of which were designed for 4K/512e drives...
It is possible to buy factory-recertified true 512 byte sector drives, but I think new ones are extinct.
What I wonder about, is if TiVo did something special with the two-tuner Premiere models, which have the 500GB drive in them. I had an opportunity to verify those drives ARE AF 4K/512e models, but not an opportunity to do anything more than read the label...
I'm not figuring I'll ever be getting another 512 byte drive, so I'm hoping some way can be figured out to align the media partitions to the 4K boundaries. It may take a little trial and error sometime in the future, but it seems worth a shot to try the Linux fdisk method described in Novell's knowledgebase paper Partition alignment of drives with internal sector size larger than 512 bytes. If that can be done immediately after a truncated restore and then have the right filesystem put back in each shifted partition, I'm hopeful that it could work. I'm just not sure how the OS would handle the change in address of the shifted partitions. If it works, it would provide us an image that can be shared with anyone else caring about aligned partitions on their 4K drives.
As for the Premiere (2-tuner), my wife mentioned that she's seen it reboot a couple times while she was watching it, so I might have a double reason to take it out to test and read the partition table with WinMFS. I'm really curious to see if TiVo actually bothers to align the partitions on it, because it seems to have similar hesitations in FF'ing shows as the THD with the WD20EURS in it. Edit: I just went and played with it a bit and I take that back - it's as fast as the 512 byte drives were.
I'm happy to see somebody as interested in this as I am. I just don't know enough about Linux, let alone the "tivoized" version of it, combined with the arcane/outdated/proprietary file system structure, to really do much about "fixing", or changing, the structure to produce an aligned, and optimized result that works.
Just taking a stock image, and tacking a ~1.7TB partition on the end isn't "optimized". Leaving 4K alignment out if the picture for a moment, one may also consider putting the partitions in a strategic layout, so the drive has to do the least amount of seeking, and shorter seeks. WinMFS did this quite well for the old TiVos it was designed for, with the drive sizes available at the time. But, it is now a very outdated utility. I'm hoping that the DVRBARS utility evolves into a utility/toolset that combines all the elements of all the existing tools/utilities, and makes them work well with current and future hardware/drives. TiVo is going to have to make some major changes in future products, if/when they break the 2TB barrier. As some have said, once they do that, all existing tools/utilities will become useless, as is.
EDIT/ADD: People have reported that they have taken drives from one model Premiere, installed it in another, and that the TiVo detected the software was wrong, then downloaded the correct software, and all worked well after the correct software was installed. So, what I'm wondering, now, is did the drive retain the partition map it had before the update? If so, there could be a very easy fix right under our noses. I only have 320GB two-tuner model Premieres. I wonder, if TiVo did align the 500GB version, if it could be cloned to a 2TB drive, put into a unit that came with a 320GB drive, get the correct software, and retain alignment... It's my understanding that using Windows 7 and DVRBARS, and virtual hard drives, that one could play around with this concept without as much effort as other ways...
I do realize that this discussion is going on in the Series 3/HD thread, but don't think all the Premiere talk takes away from the goal, which could lead to alignment and optimization for all TiVos.
EDIT/ADD: Come to think of it, the use of one model's partition structure, in order to increase capacity of another model was done before, with a forum member taking a HD XL image and gutting it of its identity, so that the image could be used on a non-XL HD, because it would download the correct software on it's maiden startup. The structure remained intact. However, distributing the image was frowned upon here, at the time, the person who made it didn't intend for it to get passed around, and the gutting process was just an experiment. It seemed most of the users of that image seemed to experience drive corruption later on down the road. I sure did. Nobody uses that method anymore. Maybe it is time to re-think that it was not a good option. Maybe it should be revisited, as a means to an end result, that doesn't become corrupt, and provides alignment and optimization...
Summary of my experiments of upgrading TiVoHD from its original 160GB drive to 2TB drive, regarding 4KB alignment.
1. WinMFS mfscopy and mfsadd with "optimized layout": 1 MFS media region unaligned, as discussed in previous messages.
2. WinMFS mfscopy and mfsadd with "unoptimized layout": multiple MFS regions unaligned. It rearranged all partitions based on the partition number. The original layout was NOT preserved. Don't bother.
3. "dd" and WinMFS mfsadd: Messed up the new partitions and crashed. Don't bother.
4. "dd" and MFSLive mfsadd: All MFS partitions are aligned. See attached picture.
That was always what I hated about WinMFS - It screwing with the offsets and layouts, even if you unselected the "optimized layout" option. You could never get an exact copy of the original layout, when imaging the drive from an image file. Maybe that worked best for Series 2 TiVos and the drive sizes available at the time (I wouldn't know).
So, do you have any ideas on how to properly "optimize" (not to be confused with 4K alignment, which is a separate matter) a 2TB drive, by splitting the media partitions into equal sizes and making the "sandwich" that WinMFS was designed to make for the equipment and drive sizes that were prevalent at the time the software was designed?
One thing that is not widely known, is that added partitions are "supposed to come in pairs". That statement/line has been reportedly found within the TiVo code, by a few people who dug into it. It must have been put into the code for a reason, and the creator of WinMFS tried to make sure that there were pairs. As of yet, nobody has proven that it actually matters. JMFS only adds one partition, consuming all the free space at the end of the drive.
Feel free to further regale us with what you know, and what you think about the questions, and possible solutions to issues, which have recently flared up. It's not often, when things like this come up, that there is anybody willing to take the time to share what they know, and others who want to dig in and try to find solutions. Look at how much one person (Comer) gave to all of us, with JMFS. Until he contributed, most had no choice, but to buy pre-imaged drives (for Premieres), where the cost of the pre-imaging generally exceeds the cost of the drive...
Do we even know if the pre-imaged drives (DVR_DUDE, Weaknees.com) are 4K aligned? Apparently you can use a non-aligned drive without realizing there's a problem for quite a while.
Can you tell us where, please?
Me too. I haven't touched the code since since patching a few things in the first week, but the obsession that made me write v1 is starting to come back.
To get 4K alignment right now I'd just take the 758 image, slap it on a WD20EURS, and see how it works in a 746 or 748. From several tests that jmbach has done it seems to download the correct image automatically even without forcing a KS52 (at least when going from a 746 to a 748). I will run the 758-748 test this morning and let you know how it goes.
Last night, I got a WD10EZRX (think that was the exact model, can't remember unless I go look), restored a 540 WinMFS image and installed in the Tivo 540080. It didn't boot up, was sitting on the power up screen for 5 min. So I put the original drive back in and the power up screen only lasted for about 1 1/2 min before the few minutes screen.
I guess I need a way to get WDidle3 to run and it would take some work since this is the only computer with SATA port. I have not even burned an ultimate boot CD yet. I guess I would also need to burn a CD with WDidle3.
We are currently in a heat wave in California and would wait until it dies down before I attempt the WDidle3.
Newegg stocks them, when they are available. Fry's sells them as well, online only (but, the prices are EXTREME).
I do believe that WD may still directly sell them. However, it's my experience that you have to search by model, rather than go through the main products listings. The same goes for Newegg (search by model number).
Sometimes, the product designation will change from "discontinued", then return to that, once the supply is exhausted, until they are once again made available.