Attached is the Utility to turn on or off TLER on Western Digital drives. (wdtler.zip)
Information from From Wikipedia, the free encyclopedia:
"Time-Limited Error Recovery (TLER): Used by Western Digital for a hard drive feature that allows improved error handling in a RAID environment. In some cases, there is a conflict whether error handling should be undertaken by the hard drive or by the RAID controller, which leads to drives being marked as unusable and significant performance degradation, when this could otherwise have been avoided. Similar technologies are called Error Recovery Control (ERC), used by competitor Seagate, and Command Completion Time Limit (CCTL), used by Samsung and Hitachi.
Effectively, TLER and similar features limit the performance of on-drive error handling, to allow RAID controllers to handle the error if problematic. In a non-RAID environment, such features are unhelpful, and manufacturers do not recommend their use.
TLER can be enabled or disabled on certain Western Digital drives, using the tool WDTLER on a DOS bootdisk. Western Digital states that this feature cannot be disabled. However users and independent editors have have reported that this feature can be disabled. The tool allows this feature to be disabled by setting the values for read and write to 0 seconds.
By default, Western Digital Enterprise Drives such as Raptor, Caviar RE2 and RE2-GP (RAID Edition) come with TLER Read "Disabled" (0 seconds) and TLER Write "Enabled" (7 seconds) while Desktop Drives such as Caviar SE, SE16, and GP come with TLER Read and Write Disabled (0 seconds).
The ability to change the TLER option on Western Digital Desktop and Enterprise hard drives coincides with the current trends in desktop computing allowing the user to have the flexibility of buying a start-up computer with a single desktop class hard drive and then upgrading to two or more drives in the future. Most of the motherboard manufacturers these days use chipsets from Intel and nVidia that include on-board RAID controllers as a standard option and anywhere from 4, 6, or up to 10 SATA ports allowing for easy upgrades to multiple hard drives and RAID capability without the requirement of purchasing specialized add-on cards. Additionally, having the choice of changing the TLER option gives the user the flexibility of purchasing the high performance drives such as the Western Digital Raptor that have TLER enabled and that are designed to run in a RAID array and using them as stand-alone single drives in their desktop computers and disabling the TLER option to enable better data recovery and lower chance of corruption and drive failures.
It is important to understand that TLER should be "Enabled" for a hard disk if it is being used in a RAID array to prevent the recovery time from a disk read or write error from taking too long and preventing the RAID controller from flagging the drive as failed and dropping the drive from the array. If a drive is dropped from an array due to it passing the timeout threshold of the RAID controller due to taking too much time performing error correction, the hard disk will need to be manually re-added to the array, requiring a re-build and re-synchronization of the hard disk with the rest of the disks in the array. In the remote possibility that two drives that do not have TLER enabled happen to encounter a disk error that takes too much time to recover, both of these drives might be flagged as failed and dropped from the RAID array, effectively breaking the array and requiring either a complete data restore from backup or manual intervention to force the array to re-recognize the drives as clean and online.
The WDTLER utility allows for the enabling or disabling of the TLER parameter in the hard disk's firmware settings allowing the user to determine the best setting for his particular usage as either a stand-alone or RAID drive. This utility is written for the DOS operating system and you will require a DOS bootable disk with this utility on it to use it.
The WDTLER utility works on and makes changes to all the connected and compatible Western Digital hard drives to the computer. It is important to remember that any change will affect all the hard drives. If you only wish to change specific hard drives on your computer then you should disconnect the other hard drives before you use this utility, then reconnect them after you are finished.
The WDTLER utility comes with three batch files, TLERSCAN.BAT to get the current state of the TLER setting on all the hard drives, TLER-ON.BAT to Enable TLER, and TLER-OFF.BAT to Disable TLER. The included TLER-ON.BAT will set the Read & Write TLER time to 7 seconds. If you wish to use a custom timeout value, you can use the WDTLER.EXE utility directly with the -r# -w# parameters to specify how many seconds the Time Limit value should be."
Information from Technician:
Please know that I have not found any motherboards with on-board raid that will work with Western Digital Velociraptors. No matter what settings or TLER on or off will allow them to work in a Raid 0, 1 or 5. One or two of the drives will always fail when doing a disk intensive operation. The only efficient way to have the velociraptors work in a raid configuration is to use a raid card.
Western Digital recommends the same, and will tell you they do not recommend using on-board raid chips.
I am using a Areca Arc1210 Raid card with 3 velociraptor drives in a Raid 5 configuration and it works flawlessly. The performance is incredible. Raid 5 with 64kb striping, I get 650+mb/s burst speed and 200+mb/s average read speed in HDTune.
I also get Disk Mark score of over 1800!
Information from From Wikipedia, the free encyclopedia:
"Time-Limited Error Recovery (TLER): Used by Western Digital for a hard drive feature that allows improved error handling in a RAID environment. In some cases, there is a conflict whether error handling should be undertaken by the hard drive or by the RAID controller, which leads to drives being marked as unusable and significant performance degradation, when this could otherwise have been avoided. Similar technologies are called Error Recovery Control (ERC), used by competitor Seagate, and Command Completion Time Limit (CCTL), used by Samsung and Hitachi.
Effectively, TLER and similar features limit the performance of on-drive error handling, to allow RAID controllers to handle the error if problematic. In a non-RAID environment, such features are unhelpful, and manufacturers do not recommend their use.
TLER can be enabled or disabled on certain Western Digital drives, using the tool WDTLER on a DOS bootdisk. Western Digital states that this feature cannot be disabled. However users and independent editors have have reported that this feature can be disabled. The tool allows this feature to be disabled by setting the values for read and write to 0 seconds.
By default, Western Digital Enterprise Drives such as Raptor, Caviar RE2 and RE2-GP (RAID Edition) come with TLER Read "Disabled" (0 seconds) and TLER Write "Enabled" (7 seconds) while Desktop Drives such as Caviar SE, SE16, and GP come with TLER Read and Write Disabled (0 seconds).
The ability to change the TLER option on Western Digital Desktop and Enterprise hard drives coincides with the current trends in desktop computing allowing the user to have the flexibility of buying a start-up computer with a single desktop class hard drive and then upgrading to two or more drives in the future. Most of the motherboard manufacturers these days use chipsets from Intel and nVidia that include on-board RAID controllers as a standard option and anywhere from 4, 6, or up to 10 SATA ports allowing for easy upgrades to multiple hard drives and RAID capability without the requirement of purchasing specialized add-on cards. Additionally, having the choice of changing the TLER option gives the user the flexibility of purchasing the high performance drives such as the Western Digital Raptor that have TLER enabled and that are designed to run in a RAID array and using them as stand-alone single drives in their desktop computers and disabling the TLER option to enable better data recovery and lower chance of corruption and drive failures.
It is important to understand that TLER should be "Enabled" for a hard disk if it is being used in a RAID array to prevent the recovery time from a disk read or write error from taking too long and preventing the RAID controller from flagging the drive as failed and dropping the drive from the array. If a drive is dropped from an array due to it passing the timeout threshold of the RAID controller due to taking too much time performing error correction, the hard disk will need to be manually re-added to the array, requiring a re-build and re-synchronization of the hard disk with the rest of the disks in the array. In the remote possibility that two drives that do not have TLER enabled happen to encounter a disk error that takes too much time to recover, both of these drives might be flagged as failed and dropped from the RAID array, effectively breaking the array and requiring either a complete data restore from backup or manual intervention to force the array to re-recognize the drives as clean and online.
The WDTLER utility allows for the enabling or disabling of the TLER parameter in the hard disk's firmware settings allowing the user to determine the best setting for his particular usage as either a stand-alone or RAID drive. This utility is written for the DOS operating system and you will require a DOS bootable disk with this utility on it to use it.
The WDTLER utility works on and makes changes to all the connected and compatible Western Digital hard drives to the computer. It is important to remember that any change will affect all the hard drives. If you only wish to change specific hard drives on your computer then you should disconnect the other hard drives before you use this utility, then reconnect them after you are finished.
The WDTLER utility comes with three batch files, TLERSCAN.BAT to get the current state of the TLER setting on all the hard drives, TLER-ON.BAT to Enable TLER, and TLER-OFF.BAT to Disable TLER. The included TLER-ON.BAT will set the Read & Write TLER time to 7 seconds. If you wish to use a custom timeout value, you can use the WDTLER.EXE utility directly with the -r# -w# parameters to specify how many seconds the Time Limit value should be."
Information from Technician:
Please know that I have not found any motherboards with on-board raid that will work with Western Digital Velociraptors. No matter what settings or TLER on or off will allow them to work in a Raid 0, 1 or 5. One or two of the drives will always fail when doing a disk intensive operation. The only efficient way to have the velociraptors work in a raid configuration is to use a raid card.
Western Digital recommends the same, and will tell you they do not recommend using on-board raid chips.
I am using a Areca Arc1210 Raid card with 3 velociraptor drives in a Raid 5 configuration and it works flawlessly. The performance is incredible. Raid 5 with 64kb striping, I get 650+mb/s burst speed and 200+mb/s average read speed in HDTune.
I also get Disk Mark score of over 1800!
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