Risk question with 4x3TB and ZFS (FreeNAS)

Discussion in 'SSDs & Data Storage' started by Trepidati0n, Sep 15, 2011.

  1. Trepidati0n

    Trepidati0n [H]ardForum Junkie

    Oct 26, 2004
    I'm considering going a somewhat simpler on my next server setup. I'm pretty confident that 9TB of usable space will keep me happy for ~3 years (which is my upgrade cycle). I was considering buying 2 HP microservers and put FreeNAS on one and WHS 2011 on the other. This gives me server capability I want as well as backup capability [1].

    Is the chance too high with the proposed system to get a failure during my recovery (from FreeNAS to WHS) or rebuild (FreeNAS drive failure)? I guess in a more simple sense, are we in an era where no matter what, that a hot spare or RAID6 is the min for 3TB + drives?

    [1] Key data is still backed up in the cloud and offsite blu-ray discs.
  2. leeleatherwood

    leeleatherwood [H]ard|Gawd

    Sep 6, 2011
    For me 3.5" drive failure is a rarity, the chance of 2 drives failing at the same time before my RAID5/Z array can rebuild itself in my opinion is too low to to worry about. This is a home server not an enterprise server that can cost hundreds of thousands of dollars worth of data loss if such an incident should happen.

    I keep my very important data backed up offsite using dropbox but will switch soon to something better. Offsite backups of important data is very important and should always be done even be done no matter your RAID setup.

    Sure losing 9 TB of illegally downloaded movies and pron would be a hassle but nothing that cannot be easily replaced.
  3. dmo580

    dmo580 Limp Gawd

    Feb 4, 2008
    i'd still cry a bit :D
  4. Abit667

    Abit667 Gawd

    Jun 21, 2004
    I have several 8x2Tb and 8x3Tb setups I manage and have seen two cases of multiple failures. One where another drive failed during a rebuild, and the other a drive started producing a lot of read errors and timeouts during the rebuild. Had these not been RAID6 the array would have hosed.

    With drives as cheap as they are and how long rebuilds can take on arrays created with 2Tb and 3Tb drives, it makes sense to add another disk and move to RAID6 just in case.
  5. Blackdragon

    Blackdragon Gawd

    Jan 19, 2003
    I agree, at another $80 or $140, could save you a lot of re-downloading.
  6. jonnyjl

    jonnyjl Limp Gawd

    Apr 12, 2009
    I have a zpool consisting of 2 8x2TB vdevs.

    I've definitely seen multiple drive failures, once on one vdev (two failures).

    I have (hot) spares so I really don't worry about it, but I'm glad I went raidz2 otherwise 20TBs would have gone down the drain.