Re: LVM questions for FC3

From: Rick Stevens (rstevens_at_vitalstream.com)
Date: 03/31/05

  • Next message: Hodgins Family: "Re: Top Posting.... LET IT DIE!" 
    Date: Wed, 30 Mar 2005 17:45:32 -0800
To: For users of Fedora Core releases <fedora-list@redhat.com>

    Mark wrote:
    > Hi,
    >
    > I have some questions regarding the use of logical volumes with FC3 systems:
    >
    > 1. What happens if a LV spans over mutliple hard disks and one of the disks fails while the server is running?
    > Can the server still keep on running on the other disks as long as no data from the broken disk is needed? Or does everything just
    > crash once one of the disks dies? As an extreme case, lets assume the broken disk does not contain any files or directories that are
    > used at all.

    Others may know more since the only LV stuff I do is where the PVs
    are actually RAID1, RAID5 or RAID10 disk arrays and I can survive the
    loss of a drive.

    In your example you aren't striping, so the volume should remain
    available as long as the volume doesn't extend onto the failed drive.
    If you had striped the LV across the drives, then a failed drive will
    fail the LV.

    > 2. How big is the performance loss? Obviously, an additional layer in the file system hierarchy does mean additional mapping and
    > handling, meaning additional processor usage, meaning performance loss. In most cases this probably does not matter, but what if I
    > use the server for example as a mysql database server?

    There should be no impact as far as performance is concerned since
    you're only involving one spindle at a time. I sure-as-hell wouldn't
    trust the volume for long--you're on very thin ice.
    ----------------------------------------------------------------------
    - Rick Stevens, Senior Systems Engineer rstevens@vitalstream.com -
    - VitalStream, Inc. http://www.vitalstream.com -
    - -
    - Vegetarian: Old Indian word for "lousy hunter" -
    ---------------------------------------------------------------------- 

    -- 
fedora-list mailing list
fedora-list@redhat.com
To unsubscribe: http://www.redhat.com/mailman/listinfo/fedora-list
  • Next message: Hodgins Family: "Re: Top Posting.... LET IT DIE!"

    Relevant Pages

    • Re: [SLE] Machine Building - Nightmare Alley - Compatibility and Upgrade
      ... On the other side I've been using Gigabyte boards with SuSE for years no ... graphic cards as the server terminal stays in text mode anyway. ... > department) that I will have to install their SuSe 9.1 distribution from ... Disks have a limited life time... ...
      (SuSE)
    • Re: Unix runs faster, maybe (was: Re: Educating potential VMS users)
      ... That's what I just suggested, Kerry: they're limited by disk I/O, not CPU, and hence CPU utilization *will* be low, even if the disks are working their little tails off. ... A server with very low CPU utilization is a *good* candidate for virtualization, since it's got lots of horsepower left over for other tasks that admins might be reluctant to run on the same OS instance: just hook up some more disks to service the added applicationand let 'er rip. ...
      (comp.os.vms)
    • Re: panic after removing usb flash disk
      ... are only interested in it for its use as a server or embedded OS. ... they 1) stopped using single disks in their multi-thousand-dollar ... ATA disks with no hotswap capability. ... I have no idea whether Juniper is a contributor to FreeBSD. ...
      (freebsd-stable)
    • Re: Exchange Disks
      ... I was looking at using a cheaper alternative with 7,200 RPM Server SATA ... Logs raid 1 mirror ... consider single drives for the OS and or Logs instead of mirrors. ... Is there some sort of rule-of-thumb for setting up disks based on a number ...
      (microsoft.public.exchange.setup)
    • Re: PowerEdge 1800 Spontaneous Reboots
      ... you're seeing the server crashing? ... I thought it could be the raid controller, but no HDD are attached to ... RAID 1 Mirror array spanning the whole of the 160GB. ... rebuilding the MBR or BOOT record with both disks plugged into the ...
      (microsoft.public.windows.server.sbs)