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How to set up ZFS using a Dell Poweredge and disk arrays (DAS).

I am completely new to this and have the following questions:

  • Does the RAID card need to be configured? (e.g. virtual device)
  • Do I need to turn the RAID card off in BIOS?
  • How does the array appear in linux? Is it listed under /dev or do other packages need to be installed before it can be seen?
Darthtrader
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1 Answers1

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It depends:

  • H200/300 and PERC9 (ie: 330, 730, 830) cards have the capability to work in pass-through mode, meaning that the disks can be directly presented to the operating system. To do that, you simply need to use unconfigured disks (ie: with no RAID metadata) and to avoid configuring any RAID array (VDISK in DELL terminology)

  • H700/710 cards does not have pass-through capability. As a workaround, you can configure each disk as an independent RAID0 array and build your ZFS pool from these "fake", single-disk arrays. This is not recommended, though, as ZFS really expect to have low-level access to your disks. You should be better off using a classical RAID5/10 array and formatting is with ZFS.

  • as DELL PERC cards really are rebranded LSI gear, it is sometime possible to reflash them with LSI firmware, which may enable passthrough. This is card/firmware dependant, though.

Finally, as the backplane is connected to the RAID card, turning it off will make the disks inaccessible.

shodanshok
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    H730 *do* have a pass-through capability as well as a `non-raid` capability (per device). – sfk Jan 14 '17 at 09:21
  • I've just checked the PERC9 (330/730/830) docs and yes, you are right. Than you for pointing that out. – shodanshok Jan 14 '17 at 10:45
  • The Dell 12Gbps SAS HBA or LSI-9207-8e would typically be used for JBODs for ZFS. Internal drives could either use the HBA330 or an LSI 9207-8i (or a Dell Hxxx card that supports pass-through mode). – JimNim Jan 16 '17 at 17:14
  • Is SMART data passed through to the OS when using the H730 in HBA mode on an R730? – TJ Zimmerman Apr 19 '20 at 07:47
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    @TJZimmerman the passing of SMART data is controller and firmware dependent. If you can't see them, you can try quering via the `megaraid` driver - ie something similar to `smartctl -a -d megaraid,0 /dev/sda`, where "0" is the disk id of the `sda` array. If using passthrough disks, you can try using `0` as disk id and `sda, sdb, sdc ... ` as disk array. – shodanshok Apr 19 '20 at 11:22