wiki:HardwareRaid
Last modified 6 years ago Last modified on 10/31/11 16:42:44

Hardware RAID

Several servers have hardware RAID controllers.

  • vagal has two identical 3ware Escalade 8506 controllers; see 3wareRaid
  • rnas is a Infrant ReadyNAS 1100 (with integrated RAID)
  • thorax has an embedded Dell PERC 5i aka LSI MegaRAID 8480e; see MegaRaid
  • sigvm3 has an embedded Dell PERC 6i aka LSI MegaRAID 1078; see MegaRaid
  • several other servers have PERC controllers but run VmwareEsxi so we have limited visibility to the RAID
  • sigmacback has an attached LacieRaid

Some other machines may run Linux SoftwareRaid.

Drive Information

While generally RAID controllers accept any drives of the same capacity in sets these days, it's a good idea to use the exact same model when possible. You can access drive model (and size) information with smartctl -i. Infrant also maintains a Hard Disk Compatibility List. Current drives are:

Host Device Model Size Size (OS)
vagal Seagate ST3500630AS 500GB 465 GiB
vagal Maxtor 6Y250M0 250GB 232 GiB
rnas Seagate ST3400620AS 400GB 372 GiB
thorax Seagate ST31000340AS 1TB 931 GiB
sigvm3 Seagate ST31000340AS 1TB 931 GiB
sigmacback Seagate ST31500341AS 1.5TB 1396 GiB
corpus1 Seagate ST32000542AS 2TB 1862 GiB
tower Seagate ST91000640NS 1TB 931 GiB

Volume Information

Typical hardware RAID controllers make information about the RAID volumes available in three ways:

  • An on-board BIOS management tool when you boot the machine
  • A monitoring and configuration daemon which provides a web interface (3dmd, Dell OMSA)
  • A command-line interface tool (tw_cli, MegaCli)

I typically prefer the command-line interface because you can use it while the machine is up to monitor things. Also, the web daemons are typically slow and very difficult to use.

The Infrant ReadyNAS rnas also has SSH.

Older Benchmarks

Each night's backup first creates a full hardlinked copy of the previous day's set. This is the one operation that takes the most time for the SIG backups as it involves many small read/write operations (stat, mkdir, ln). Real-world read/write of large files gives much different benchmarks; in particular the Infrant ReadyNAS does much better which makes sense as it is designed as a low-power home media server.

  1. cp -al of yesterday's /usr/local/data
Host Time (sec) Hardware
thorax 531 PERC/5i across 3x 7200 RPM SATA2 drives
vastus 730 3ware 7850 across 6x 5400 RPM ATA-133 drives
vagal 903 3ware 8506 across 3x 7200 RPM SATA drives
readynas 27900* ReadyNAS 1100 across 3x 7200 RPM SATA drives
  • Not a typo
  1. cp -al of yesterday's /home
Host Time (sec) Hardware
thorax 324 PERC/5i across 3x 7200 RPM SATA2 drives
vastus 503 3ware 7850 across 6x 5400 RPM ATA-133 drives
vagal 1008 3ware 8506 across 3x 5400 RPM SATA drives
readynas 18000* ReadyNAS 1100 across 3x 7200 RPM SATA drives
  • Not a typo