feat: Add support for setting stripe size for LVM RAID

[vojtechtrefny]

Custom stripe size is needed for SAP HANA. We are using here the existing 'raid_chunk_size' property, the "chunk size" term comes from MD RAID where it has the same meaning as "stripe size" for LVM RAID.

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -0.02 ⚠️

Comparison is base (1b4b4c5) 13.90% compared to head (b34c7f7) 13.88%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #355      +/-   ##
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- Coverage   13.90%   13.88%   -0.02%     
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  Files           8        8              
  Lines        1705     1707       +2     
  Branches       71       71              
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  Hits          237      237              
- Misses       1468     1470       +2     

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Impacted Files	Coverage Δ
library/blivet.py	0.00% <0.00%> (ø)

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[vojtechtrefny]

I decided to reuse the raid_chunk_size argument for the LVM RAID stripe size here. I am not 100 % sure this is the best approach -- I wanted to avoid adding another LVM RAID specific argument when chunk and stripe size is basically the same thing in MD and LVM RAID, but it might be confusing. @dwlehman @richm what do you think?

[richm]

I decided to reuse the raid_chunk_size argument for the LVM RAID stripe size here. I am not 100 % sure this is the best approach -- I wanted to avoid adding another LVM RAID specific argument when chunk and stripe size is basically the same thing in MD and LVM RAID, but it might be confusing. @dwlehman @richm what do you think?

I would prefer to have some parameter with stripe_size in the name, but if 1) it will be difficult to add a new parameter and 2) storage admins will know that chunk_size and stripe_size are the same concept, then works for me. @briansmith0 wdyt?

[briansmith0]

+1 to the comment from @richm

[vojtechtrefny]

Thank you for the feedback, I didn't realize that chunk size is also used by LVM for thin pools so using it for RAID could be confusing. #357 is replacement for this adding a new raid_stripe_size argument.