3 ms·

Why not use the Raid Edition drives if you're at it? Supposedly better mtbf, longer warranty, and the to-me-unquantifiably-better TLER feature.

by lutorm 17y ago

lsc 17y ago
TLER is well worth the 50% premium, in many cases. With desktop firmware, my experience has been that fully half the time when a disk fails, it doesn't properly fail, it retries forever. Linux MD and 3ware hardware raid (the only hardware raid I tried) both hang up waiting for the drive to fail. (the 3ware keeps resetting the drive... but it will sit there and suck for two days just like md) Back when I used desktop drives, I had several outages caused by a bad disk in a mirror. I log into the box and manually fail it out of the raid and we are good, but customers tend to get mad when their I/O hangs for hours on end. It only takes one hung mirror in production, for me at least, to pay for a whole lot of 'enterprise' firmware drives.
- dhess 17y ago
  Many (most?) new consumer drives have support for ERC (the standard term for what WD calls "TLER"), which is part of the ATA-8 standard. See here for the spec (ERC is described in section 8.3.4): http://www.t13.org/Documents/UploadedDocuments/docs2007/D1699r4a-ATA8-ACS.pdf http://www.t13.org/Documents/UploadedDocuments/docs2007/D169... Until recently, you often needed a vendor-supplied MS-DOS executable to enable or modify ERC features on consumer drives, but smartmontools supports it as of v5.40, thanks to this guy: http://www.csc.liv.ac.uk/~greg/projects/erc/ http://www.csc.liv.ac.uk/~greg/projects/erc/ I just bought a 1.5TB Samsung HD154UI for $99 that supports ERC. There are reports that P-model variants of the WD 15EADS don't support TLER anymore, but I have several S- and R-model variants of that drive that do, including one that was manufactured in March; so it's still possible to get WD consumer drives that support TLER/ERC, you just have to be picky about the variant.
  - lsc 17y ago
    huh. neat. where are you finding out what is and is not supported? user forms? or do drive data sheets actually have useful info?
    - dhess 17y ago
      It's purely anecdotal. HardForum is a good source of information because of its enthusiast user base. A large group of home NAS builders post there.

Why not use the Raid Edition drives if you're at it? Supposedly better mtbf, longer warranty, and the to-me-unquantifiably-better TLER feature.

by lutorm 17y ago

Why not use the Raid Edition drives if you're at it? Supposedly better mtbf, longer warranty, and the to-me-unquantifiably-better TLER feature.

lsc 17y ago

TLER is well worth the 50% premium, in many cases. With desktop firmware, my experience has been that fully half the time when a disk fails, it doesn't properly fail, it retries forever. Linux MD and 3ware hardware raid (the only hardware raid I tried) both hang up waiting for the drive to fail. (the 3ware keeps resetting the drive... but it will sit there and suck for two days just like md) Back when I used desktop drives, I had several outages caused by a bad disk in a mirror. I log into the box and manually fail it out of the raid and we are good, but customers tend to get mad when their I/O hangs for hours on end. It only takes one hung mirror in production, for me at least, to pay for a whole lot of 'enterprise' firmware drives.

dhess 17y ago
Many (most?) new consumer drives have support for ERC (the standard term for what WD calls "TLER"), which is part of the ATA-8 standard. See here for the spec (ERC is described in section 8.3.4): http://www.t13.org/Documents/UploadedDocuments/docs2007/D1699r4a-ATA8-ACS.pdf http://www.t13.org/Documents/UploadedDocuments/docs2007/D169... Until recently, you often needed a vendor-supplied MS-DOS executable to enable or modify ERC features on consumer drives, but smartmontools supports it as of v5.40, thanks to this guy: http://www.csc.liv.ac.uk/~greg/projects/erc/ http://www.csc.liv.ac.uk/~greg/projects/erc/ I just bought a 1.5TB Samsung HD154UI for $99 that supports ERC. There are reports that P-model variants of the WD 15EADS don't support TLER anymore, but I have several S- and R-model variants of that drive that do, including one that was manufactured in March; so it's still possible to get WD consumer drives that support TLER/ERC, you just have to be picky about the variant.
- lsc 17y ago
  huh. neat. where are you finding out what is and is not supported? user forms? or do drive data sheets actually have useful info?
  - dhess 17y ago
    It's purely anecdotal. HardForum is a good source of information because of its enthusiast user base. A large group of home NAS builders post there.