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#1
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Deframenter That Will Create New Hard Drive?
After seeing how much work some defragmenters will go through to do their
job, I'm wondering does anyone make a defragmenter that could be ordered to actually construct a new drive as the result of the defragmentation? In other words, rather than just shuffling sectors around, the fragmenter would write out a whole new drive, with all of the sectors nicely ordered. This would likely be a much faster way to defragment for those extreme cases when you want to physically order files based on filename spelling, so that consecutive files are contiguous on the drive. This is important for games like flight simulators that need to load thousands of very small files in very short periods of time, where disk latency accumulates across the large numbers of files and really does affect load times. It seems to me that this kind of defragmenter might also make an interesting way to do an image backup of a drive while it is in use. Obviously there is a risk if doing that for certain types of database files that are actively in use at the time of the defragmentation, but caveat emptor and all that. -- Will |
#2
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Deframenter That Will Create New Hard Drive?
Will wrote:
After seeing how much work some defragmenters will go through to do their job, I'm wondering does anyone make a defragmenter that could be ordered to actually construct a new drive as the result of the defragmentation? In other words, rather than just shuffling sectors around, the fragmenter would write out a whole new drive, with all of the sectors nicely ordered. This would likely be a much faster way to defragment for those extreme cases when you want to physically order files based on filename spelling, so that consecutive files are contiguous on the drive. This is important for games like flight simulators that need to load thousands of very small files in very short periods of time, where disk latency accumulates across the large numbers of files and really does affect load times. It seems to me that this kind of defragmenter might also make an interesting way to do an image backup of a drive while it is in use. Obviously there is a risk if doing that for certain types of database files that are actively in use at the time of the defragmentation, but caveat emptor and all that. I've been doing that with Ghost for some time. -- The e-mail address in our reply-to line is reversed in an attempt to minimize spam. Our true address is of the form . |
#3
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Deframenter That Will Create New Hard Drive?
Will wrote:
After seeing how much work some defragmenters will go through to do their job, I'm wondering does anyone make a defragmenter that could be ordered to actually construct a new drive as the result of the defragmentation? In other words, rather than just shuffling sectors around, the fragmenter would write out a whole new drive, with all of the sectors nicely ordered. Some backup system produce that result with the restore. This would likely be a much faster way to defragment for those extreme cases when you want to physically order files based on filename spelling, so that consecutive files are contiguous on the drive. You dont need to defrag for that, you dont need to move the files around, just the entrys in the directorys. And you dont necessarily need to sort them anyway if the directorys are properly cached in memory. This is important for games like flight simulators that need to load thousands of very small files in very short periods of time, where disk latency accumulates across the large numbers of files and really does affect load times. Nope, that's what the OS file cache is for. It seems to me that this kind of defragmenter might also make an interesting way to do an image backup of a drive while it is in use. No point, real imagers do much more, particularly incremental images. Obviously there is a risk if doing that for certain types of database files that are actively in use at the time of the defragmentation, but caveat emptor and all that. |
#4
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Deframenter That Will Create New Hard Drive?
"CJT" wrote in message
... It seems to me that this kind of defragmenter might also make an interesting way to do an image backup of a drive while it is in use. Obviously there is a risk if doing that for certain types of database files that are actively in use at the time of the defragmentation, but caveat emptor and all that. I've been doing that with Ghost for some time. Ghost is just imaging right? In my method you defrag and then end up with an image backup as a side effect. To do things with Ghost you need to defrag and then image separately, taking more time. -- Will |
#5
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Deframenter That Will Create New Hard Drive?
"Rod Speed" wrote in message
... After seeing how much work some defragmenters will go through to do their job, I'm wondering does anyone make a defragmenter that could be ordered to actually construct a new drive as the result of the defragmentation? In other words, rather than just shuffling sectors around, the fragmenter would write out a whole new drive, with all of the sectors nicely ordered. Some backup system produce that result with the restore. True enough. It's all about how much time do you have as usual. That method is not optimal because you must backup, then verify, then get a third volume and restore (assuming you don't want to risk your original). This would likely be a much faster way to defragment for those extreme cases when you want to physically order files based on filename spelling, so that consecutive files are contiguous on the drive. You dont need to defrag for that, you dont need to move the files around, just the entrys in the directorys. No, that is just wrong. Assume that you need to open 1000 small files that are highly fragmented on the disk. Each file, because it is not contiguous with the previous file, requires a disk seek, with a typical seek for a SATA drive being 9 ms. For a 7200 rpm drive, once you have seeked to a track, you have an average 4 ms of latency to get to the start sector for the file. That is 12 ms of latency per file, and I need to open 1000 files. Simple math tells you that you have 12,000 ms - 12 full seconds - of extra loading time introduced in this scenario attributable to physical fragmentation of the files on disk. As a simple thought experiment, assume that all of the files are organized by filename sequentially in the directory, which is your proposed solution. The time to load that entire directory would never be more than 100 or 200 ms, and that would be a huge directory. The additional time spent by the computer to sort even 2000 filenames in an unsorted directory is not more than maybe another 50 ms. I'm being generous to your argument. So your solution is based on optimizing a process that takes at most 250 ms and saves at most maybe 50 ms, and you are ignoring the very real and very measurable costs associated with the seek and latency for loading 1000 files. 50 ms in savings versus up to 12,000 ms in savings is not a good tradeoff. This is important for games like flight simulators that need to load thousands of very small files in very short periods of time, where disk latency accumulates across the large numbers of files and really does affect load times. Nope, that's what the OS file cache is for. In a perfect world I would have a 12 GB memory cache in front of the file system and some tool to preload that cache. Maybe next year, but not on this year's hardware, thanks. -- Will |
#6
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Deframenter That Will Create New Hard Drive?
Will wrote
Rod Speed wrote Will wrote After seeing how much work some defragmenters will go through to do their job, I'm wondering does anyone make a defragmenter that could be ordered to actually construct a new drive as the result of the defragmentation? In other words, rather than just shuffling sectors around, the fragmenter would write out a whole new drive, with all of the sectors nicely ordered. Some backup system produce that result with the restore. True enough. It's all about how much time do you have as usual. That method is not optimal because you must backup, then verify, You dont really need to verify. then get a third volume and restore (assuming you don't want to risk your original). Yes, but defragging is a complete waste of time anyway. This would likely be a much faster way to defragment for those extreme cases when you want to physically order files based on filename spelling, so that consecutive files are contiguous on the drive. You dont need to defrag for that, you dont need to move the files around, just the entrys in the directorys. No, that is just wrong. Nope. Assume that you need to open 1000 small files that are highly fragmented on the disk. Small files are very unlikely to be fragmented, they normally wont occupy more than one cluster and so by definition cant be fragmented. Each file, because it is not contiguous with the previous file, Thats not what fragmented means. That is poorly organised. requires a disk seek, with a typical seek for a SATA drive being 9 ms. You aint established that that time is significant as part of the time involved in loading those 1K files. For a 7200 rpm drive, once you have seeked to a track, you have an average 4 ms of latency to get to the start sector for the file. That is 12 ms of latency per file, and I need to open 1000 files. You've mangled the maths there too. Simple math tells you that you have 12,000 ms - 12 full seconds - of extra loading time introduced in this scenario attributable to physical fragmentation of the files on disk. A properly written app wont have 1K of small files. As a simple thought experiment, assume that all of the files are organized by filename sequentially in the directory, which is your proposed solution. No it isnt. I was just proposing sorting the FILE ENTRYS IN THE DIRECTORY, not the files themselves. The time to load that entire directory would never be more than 100 or 200 ms, Wrong again. and that would be a huge directory. And an obscenely badly written app. The additional time spent by the computer to sort even 2000 filenames in an unsorted directory is not more than maybe another 50 ms. They arent sorted. I'm being generous to your argument. You havent even managed to grasp what I was suggesting. So your solution is based on optimizing a process that takes at most 250 ms and saves at most maybe 50 ms, Wrong. and you are ignoring the very real and very measurable costs associated with the seek and latency for loading 1000 files. Nope. 50 ms in savings versus up to 12,000 ms in savings is not a good tradeoff. Only the most badly written app would attempt to load 1K files from the drive as fast as it can. This is important for games like flight simulators that need to load thousands of very small files in very short periods of time, where disk latency accumulates across the large numbers of files and really does affect load times. Nope, that's what the OS file cache is for. In a perfect world I would have a 12 GB memory cache in front of the file system and some tool to preload that cache. You dont need a 12 GB cache when its 1K very small files. Maybe next year, but not on this year's hardware, thanks. Dont need any new hardware, just have whatever is in those 1K files in a single file, stupid. |
#7
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Deframenter That Will Create New Hard Drive?
"Rod Speed" wrote in message
... Each file, because it is not contiguous with the previous file, requires a disk seek, with a typical seek for a SATA For a 7200 rpm drive, once you have seeked to a track, you have an average 4 ms of latency to get to the start sector for the file. That is 12 ms of latency per file, and I need to open 1000 files. You've mangled the maths there too. Do the math correctly for us. There isn't any point to responding to your many generalizations that have zero hard data or mathematical analysis as backup to the points you want to make. No free rides. Do the math and commit it to public scrutiny. -- Will |
#8
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Deframenter That Will Create New Hard Drive?
Will wrote
Rod Speed wrote Each file, because it is not contiguous with the previous file, requires a disk seek, with a typical seek for a SATA For a 7200 rpm drive, once you have seeked to a track, you have an average 4 ms of latency to get to the start sector for the file. That is 12 ms of latency per file, and I need to open 1000 files. You've mangled the maths there too. Do the math correctly for us. Just how many of you are there between those ears ? No point in the math, any app designer with a clue wouldnt have 1K of tiny files all loaded at once as fast as it can. There isn't any point to responding to your many generalizations that have zero hard data or mathematical analysis as backup to the points you want to make. Dont need any 'mathematical analysis' to realise that the only thing that makes any sense at all is to have that data in a single file instead of 1K separate tiny files if you are going to load all that data as quickly as possible, stupid. No free rides. Do the math and commit it to public scrutiny. Go and **** yourself. |
#9
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Deframenter That Will Create New Hard Drive?
Will wrote:
"CJT" wrote in message ... It seems to me that this kind of defragmenter might also make an interesting way to do an image backup of a drive while it is in use. Obviously there is a risk if doing that for certain types of database files that are actively in use at the time of the defragmentation, but caveat emptor and all that. I've been doing that with Ghost for some time. Ghost is just imaging right? In my method you defrag and then end up with an image backup as a side effect. To do things with Ghost you need to defrag and then image separately, taking more time. Not so, at least on the version I use. You can create a true image by setting an option, but the default does a file-by-file copy. -- The e-mail address in our reply-to line is reversed in an attempt to minimize spam. Our true address is of the form . |
#10
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Deframenter That Will Create New Hard Drive?
"Rod Speed" wrote in message
... Will wrote Each file, because it is not contiguous with the previous file, requires a disk seek, with a typical seek for a SATA For a 7200 rpm drive, once you have seeked to a track, you have an average 4 ms of latency to get to the start sector for the file. That is 12 ms of latency per file, and I need to open 1000 files. You've mangled the maths there too. Do the math correctly for us. Just how many of you are there between those ears ? No point in the math, any app designer with a clue wouldnt have 1K of tiny files all loaded at once as fast as it can. There isn't any point to responding to your many generalizations that have zero hard data or mathematical analysis as backup to the points you want to make. Dont need any 'mathematical analysis' to realise that the only thing that makes any sense at all is to have that data in a single file instead of 1K separate tiny files if you are going to load all that data as quickly as possible, stupid. Rod, you are changing the subject. I calculated the latency attributable to opening 1000 non contiguous files on a SATA drive. You responded to that by saying I did the math wrong in that calculation, and you supplied no math of your own. If I did the math wrong, then do the math right and explain what was wrong with the number I gave. Now you are trying to dodge your own claim and instead change the topic to how to redesign a commercial game to do things in a different way than it does it. Okay, the game is designed badly. It opens a lot of very small files in a very short time. Sorry. You can go convince Microsoft that what they are doing is wrong. I'm sure they had a reason for it, but I wasn't here to play Don Quixote with Microsoft. I was here to try to just solve the real world problem I need to solve, which was to make the files contiguous on the drive to avoid the latency of opening those files when they are non contiguous. Your solution for creating a drive that lines up the files contiguoulsly by using a backup and restore is a good solution. No problems there. But if you are going to say to someone that their calculation of some effect is wrong, you should be prepared to present your own numbers, not just change the topic to a variety of other sub topics. Otherwise your claim doesn't have credibility. Saying that you don't need to backup your claims because there are "other problems" doesn't establish your initial claim either. -- Will |
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