Attachment 150145 Details for Bug 134638 – Some comments on what was done.

Some comments on what was done.

Notes (text/plain), 4.35 KB, created by Joel Andres Granados on 2007-03-15 17:34:21 UTC

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Creator: Joel Andres Granados

Created: 2007-03-15 17:34:21 UTC

Size: 4.35 KB

patch

obsolete

>Planned changes:
>1.  pykickstart/commands/logvol.py:
>    Include a new LogVol class called FC7_LogVol, This class
>    will include the new --stripedevs and --stripesize options
>    --stripedevs receives a string of "," separated devices
>    --stripesize recieves an int identifying the stripe size in KB.
>    The lv will be striped when the stripedevs is specified, if the
>    stripedevs is specified and the stripesize isnot, stripe size
>    will default to 2048 KB.  If stripesize is specified and
>    stripedevs is not, stripesize will be ignored.
>
>2.  kickstart.py:
>    - The LogVol class will inherit from the newly created
>      FC7_LogVol so it can put the new values in to the 
>      lvrequest.
>    - At the moment of creating the request the devices have to
>      be mapped with the mapping used by the VG.  Two variables
>      are needed: 
>      self.handler.ksPVMapping (Hold the relation ship between 
>      the pvs in the kickstart and the ones in the VG) 
>      self.handler.id.partitions.autoPartitionRequests 
>      (The list of the autopartitions that are being used. - 
>      need it to find the volume group and the PV real name)
>      To get the device name simple self.handler.id.partitions.\
>      autoPartitionRequests[offsetOfDev].drive
>
>3.  partRequest.py:
>    we have to change the LogicalVolumeRequestSpec so it can
>    accept the two new values. (stripesize and stripedevs)
>    - adding the default values to the class.
>    - adding some sanity checks to the class.
>    - adding some string information for when the class returns
>      a string.
>    - adding some additional infomration to the getActualSize()
>      function in the LogicalVolumeRequestSpec class.  The real
>      size of a striped lv changes a bit and this has to be
>      addressed.
>    ISUE: The devices dont get asinged device files until after
>    the LogicalVolumeRequestSpec(lvrs) is created.  Additionally
>    if the lvrs is striped it must return the device file for 
>    each stripe (The devs are needed at striped lv creation.) 
>    To resolve this issue the list of the devices is created with
>    only the dictionary keys (The keys are the request uinique id)
>    afterwards when the lvrs is about to return from the getDevice 
>    function it should look into the requests list and find the 
>    device files.  Each device, at this point must have a 
>    specified file that will be used to complete the dictionary 
>    specification.
>    - adding two variables to the class:
>        self.stripesize - size in KB.
>        self.stripedevs - {physicalvolumerequestid:"devName"}
>                          It will be a dictionary.
>
>4.  fsset.py:
>    - change the actual making of the lvm.  Remember that stripes
>      go first to avoid the linear lvs taking the striped space.
>
>5.  partitions.py:
>    - Given the different behavior in space from the striped lvs
>      additional analysis must be done in the general sanity check
>      function (sanityCheckAllRequests).
>      If a grow or a percentage option was selected we need to 
>      rais an error.
>      The we check for the available size in the logical volume and
>      make sure it is enough to fit out striped lvs. [*].
>      We created an additional function that tests for space in the 
>      volume group for the individual striped lvs.
>
>6.  lvm.py:
>    - Changed the creating of the individual lvs.  If striped added
>    the striped option.  If not, left it the way it was.
>
>*We test the volume group to see if the stripe sizes are possible with
>the current device list.  At the same time we take care no to increase 
>the lv size so the other vg and lv sanity checks are valid.
>
>Issues:
>1. The percent option in the striped lvs does not work. will put a 
>   conditional to catch the error for now.
>2. The grow option in the striped lvs is does not work. will put a 
>   condidtional to catch the error for now.
>3. The recommended option in the striped lvs does not work.  will 
>   put a conditional to catch the error for now.
>4. striped lvm on raid is not implemented.
>
>Future Development:
>1.  Add the --grow option.
>2.  Add the --percent option.
>3.  The --recommended option shows some strange behavior, don't know
>    if it will be added in the future.
>4.  Add the lvm on top or RAID functionality.
>5.  Implement mirrored lvs.
>6.  Allow linear lvs to choose their pvs.
>
>Additional info:
>1. Strange behaviour when using the --recommended option.  This is from
>   The original code.

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