Take a look at 'dumpe2fs /dev/mapper/vg_222-lvol0'. You will see the Block Count, Block Size, Reserved Blocks, etc... I'm sure there is some math in there that will hopefully explain it.
I have a 200G filesystem I looked at, and see a similar discrepancy to yours (lvdisplay shows 200G, df shows 197G). The math I tried: (Block Count * Block Size) - (Reserved Block Count * Block Size) = 190G 200G * 95% = 190G (accounting for the default 5% reserve) So, I don't think the df is subtracting out the reserved blocks... There is also going to be some reserved space for journals, metadata, etc. Its an interesting question - I hope you find the answer and share it! Thanks, Kevin -----Original Message----- From: rhelv5-list-boun...@redhat.com [mailto:rhelv5-list-boun...@redhat.com] On Behalf Of Domenico Viggiani Sent: Wednesday, September 21, 2011 11:46 PM To: 'Red Hat Enterprise Linux 5 (Tikanga) discussion mailing-list' Subject: Re: [rhelv5-list] FS size in df output differs from lvol size > How about using "lvdisplay" to display your LV? You are looking at the > VG size which is NOT the same as the LV size :) Ok :) > What does 'lvdisplay /dev/mapper/vg_222-lvol0' show? # lvdisplay --units=g /dev/mapper/vg_222-lvol0 --- Logical volume --- LV Name /dev/vg_222/lvol0 VG Name vg_222 LV UUID ILh01Z-Tr32-QJJk-Ox3i-ATXO-FFWg-63QSXm LV Write Access read/write LV Status available # open 1 LV Size 420.00 GB Current LE 107519 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:7 # df --block-size=G /dev/mapper/vg_222-lvol0 Filesystem 1G-blocks Used Available Use% Mounted on /dev/mapper/vg_222-lvol0 414G 332G 74G 82% /database/synth > One other thing to be aware of is that an LV can be resized and if the > filesystem is not also resized they will not match. # resize2fs /dev/vg_222/lvol0 resize2fs 1.39 (29-May-2006) The filesystem is already 110099456 blocks long. Nothing to do! > Also, depending on the filesystem blocksize, you may not be able to use > every byte in the LV for your file system Can you explain further? 6G of waste on 420G total? Thanks -- DV _______________________________________________ rhelv5-list mailing list rhelv5-list@redhat.com https://www.redhat.com/mailman/listinfo/rhelv5-list _______________________________________________ rhelv5-list mailing list rhelv5-list@redhat.com https://www.redhat.com/mailman/listinfo/rhelv5-list
