6 Reasons You Might Not Be Reaching Your Maximum Tape Drive Capacity
Most tape formats detail the maximum local capacity (without compression) and the maximum compressed capacity. These figures are approximate maximum capacities for the tape drive and these maximums are obtained under ideal conditions.
Because real-world systems seldom meet perfect conditions, you may be unable to achieve the stated maximums. As an example, the kind of information you are endeavoring to compress has a great effect on capacity. Some types of info just don't compress well.
If you're seeing significantly lower capacity, it could be due to a few of the following reasons:
The tape drive's information compression is not enabled. Tape drives that compress info use compression by default. But there are tactics for tape drive compression to be turned off thru the backup application. Test your application to work out if it has a setting for hardware compression. In most cases, you will be wanting to confirm hardware compression is turned on.
You may be writing data that does not compress well.Maximum capacities for tapes are typically based totally on a median 2:1 info compression proportion (or 2.5:1 for Exabyte M2 drives and some Sony AIT drives). Some sorts of information compress at a higher proportion; others compress at a lower proportion. For example, executable files and graphics files typically do not compress well.
The tape drive might be attempting to compress data that is already compressed.If your backup program compresses info before sending it to the tape drive, the tape drive can't compress it further. In fact , the additional attempt at compression may cause the data to grow. Do not use both software and hardware info compression. If the tape drive is about to compress information, switch off the software compression in your backup application.In the same way, compressed files on your hard disk will not compress any further when fed through the tape drive's hardware compression chip. If you are backing up a high percentage of already compressed files, such as MP3, AVI, and JPG files, then you will not see any farther compression at the tape drive level. In fact , as the info is compressed twice, it may very well expand. Try turning off hardware compression and software compression in your backup application.
Your system may struggle to stay alongside of the tape drive.If your computer doesn't send info to the tape drive as fast as the tape drive can write info to the tape, the tape drive stops and waits for the PC. Each time the tape drive stops, it writes gap tracks (tracks of undefined info) to aid in repositioning when more information becomes available. If the tape drive has to stop and restart frequently, tape capacity is affected. Check if there are transfer bottlenecks in your system. For instance, if you are backing up information over a 100bT network, a typical transfer rate could be much more slowly than you expect. In this example, changing the network to at least 1GbE and for should improve both transfer rates and tape capacity. For the most recent servers and LTO5 drives, a full 6Gb/sec should be supplied to the tape drive.
Your tape might be prepared for retirement.If you use a tape that is well worn, the tape drive could be performing high numbers of rewrites to correct blunders. Over the top rewrites cut back the tape's capacity. Try cleaning the tape drive with the right cleaning tape for your gadget using a new tape, and ensure you are using high quality data cartridges.
Your tape drive may need to be cleaned.A buildup of debris in the tape drive or on the recording heads can end up in increased error rates and rewrites. If you haven't cleaned your tape drive recently, try cleaning it with the correct Cleaning Cartridge for your tape drive model.
Because real-world systems seldom meet perfect conditions, you may be unable to achieve the stated maximums. As an example, the kind of information you are endeavoring to compress has a great effect on capacity. Some types of info just don't compress well.
If you're seeing significantly lower capacity, it could be due to a few of the following reasons:
The tape drive's information compression is not enabled. Tape drives that compress info use compression by default. But there are tactics for tape drive compression to be turned off thru the backup application. Test your application to work out if it has a setting for hardware compression. In most cases, you will be wanting to confirm hardware compression is turned on.
You may be writing data that does not compress well.Maximum capacities for tapes are typically based totally on a median 2:1 info compression proportion (or 2.5:1 for Exabyte M2 drives and some Sony AIT drives). Some sorts of information compress at a higher proportion; others compress at a lower proportion. For example, executable files and graphics files typically do not compress well.
The tape drive might be attempting to compress data that is already compressed.If your backup program compresses info before sending it to the tape drive, the tape drive can't compress it further. In fact , the additional attempt at compression may cause the data to grow. Do not use both software and hardware info compression. If the tape drive is about to compress information, switch off the software compression in your backup application.In the same way, compressed files on your hard disk will not compress any further when fed through the tape drive's hardware compression chip. If you are backing up a high percentage of already compressed files, such as MP3, AVI, and JPG files, then you will not see any farther compression at the tape drive level. In fact , as the info is compressed twice, it may very well expand. Try turning off hardware compression and software compression in your backup application.
Your system may struggle to stay alongside of the tape drive.If your computer doesn't send info to the tape drive as fast as the tape drive can write info to the tape, the tape drive stops and waits for the PC. Each time the tape drive stops, it writes gap tracks (tracks of undefined info) to aid in repositioning when more information becomes available. If the tape drive has to stop and restart frequently, tape capacity is affected. Check if there are transfer bottlenecks in your system. For instance, if you are backing up information over a 100bT network, a typical transfer rate could be much more slowly than you expect. In this example, changing the network to at least 1GbE and for should improve both transfer rates and tape capacity. For the most recent servers and LTO5 drives, a full 6Gb/sec should be supplied to the tape drive.
Your tape might be prepared for retirement.If you use a tape that is well worn, the tape drive could be performing high numbers of rewrites to correct blunders. Over the top rewrites cut back the tape's capacity. Try cleaning the tape drive with the right cleaning tape for your gadget using a new tape, and ensure you are using high quality data cartridges.
Your tape drive may need to be cleaned.A buildup of debris in the tape drive or on the recording heads can end up in increased error rates and rewrites. If you haven't cleaned your tape drive recently, try cleaning it with the correct Cleaning Cartridge for your tape drive model.
About the Author:
The writer is a lto repair expert running a local business concentrating on lto repairs and network attached storage.
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