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* [linux-lvm] lv raid - how to read this?
@ 2017-09-07  8:06 lejeczek
  2017-09-07  9:16 ` Zdenek Kabelac
  0 siblings, 1 reply; 15+ messages in thread
From: lejeczek @ 2017-09-07  8:06 UTC (permalink / raw)
  To: linux-lvm

hi fellas

I'm setting up a lvm raid0, 4 devices, I want raid0 and I 
understand & expect - there will be four stripes, all I care 
of is speed.
I do:
$ lvcreate --type raid0 -i 4 -I 16 -n 0 -l 96%pv 
intel.raid0-0 /dev/sd{c..f} # explicitly four stripes

I see:
$ mkfs.xfs /dev/mapper/intel.sataA-0 -f
meta-data=/dev/mapper/intel.sataA-0 isize=512    agcount=32, 
agsize=30447488 blks
          =                       sectsz=512   attr=2, 
projid32bit=1
          =                       crc=1        finobt=0, 
sparse=0
data     =                       bsize=4096   
blocks=974319616, imaxpct=5
          =                       sunit=4      swidth=131076 
blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=475744, 
version=2
          =                       sectsz=512   sunit=4 blks, 
lazy-count=1
realtime =none                   extsz=4096   blocks=0, 
rtextents=0

What puzzles me is xfs's:
  sunit=4      swidth=131076 blks
and I think - what the hexx?

In a LVM non-raid stripe scenario I've always remember it 
was: swidth = sunit * Y where Y = number of stripes, right?

I'm hoping some expert could shed some light, help me(maybe 
others too) understand what LVM is doing there? I'd appreciate.
many thanks, L.

^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2017-09-08 12:11 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-09-07  8:06 [linux-lvm] lv raid - how to read this? lejeczek
2017-09-07  9:16 ` Zdenek Kabelac
2017-09-07 13:12   ` lejeczek
2017-09-07 16:27     ` Heinz Mauelshagen
2017-09-08  9:39       ` lejeczek
2017-09-08  8:49     ` Zdenek Kabelac
2017-09-08  9:22       ` lejeczek
2017-09-08  9:34         ` Zdenek Kabelac
2017-09-08  9:39           ` lejeczek
2017-09-08  9:54             ` Zdenek Kabelac
2017-09-08  9:38         ` Zdenek Kabelac
2017-09-08 10:23           ` lejeczek
2017-09-08 10:58           ` Ming-Hung Tsai
2017-09-08 11:00             ` Ming-Hung Tsai
2017-09-08 12:11               ` Zdenek Kabelac

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