Re: convert logical sector -> physical sector + pv/vg extent number
Roland <[email protected]>
| Newsgroups | gmane.linux.lvm.general |
|---|---|
| Message-ID | <[email protected]> |
> any chance to get retrieve this information for automated/script based processing ? after long trial and error and reading manpages, i got it (see below): what i'm yet missing is how "translation" of the headings/fields in normal output can be avoided , i.e print the technical/internal field name instead of a "human readable" or "translated" one. 'seg_start_pe' and 'pvseg_start' for example both translate to "Start", and that does not only make it hard to read (and makes no real sense to have duplicate field names) , but it's also difficult to build an appropriate output field command option from the default output. i remember i had such issue with other tools... think this is a missing feature ? roland # pvs --segments -olv_name,seg_start_pe,seg_size_pe,pvseg_start -S lv_name=usedblocks -O seg_start LV Start SSize Start usedblocks 0 1 512 usedblocks 1 233 1 usedblocks 234 1 513 usedblocks 235 277 235 # pvs --segments -olv_name,seg_start_pe,seg_size_pe,pvseg_start -S lv_name=markedbad -O seg_start LV Start SSize Start markedbad 0 1 1022 markedbad 1 1 0 markedbad 2 1 234 # pvs --segments -olv_name,seg_start_pe,seg_size_pe,pvseg_start -S lv_name=markedbad -O seg_start --nameprefixes --noheadings LVM2_LV_NAME='markedbad' LVM2_SEG_START_PE='0' LVM2_SEG_SIZE_PE='1' LVM2_PVSEG_START='1022' LVM2_LV_NAME='markedbad' LVM2_SEG_START_PE='1' LVM2_SEG_SIZE_PE='1' LVM2_PVSEG_START='0' LVM2_LV_NAME='markedbad' LVM2_SEG_START_PE='2' LVM2_SEG_SIZE_PE='1' LVM2_PVSEG_START='234' # pvs --segments -olv_name,seg_start_pe,seg_size_pe,pvseg_start -S lv_name=usedblocks -O seg_start --nameprefixes --noheadings LVM2_LV_NAME='usedblocks' LVM2_SEG_START_PE='0' LVM2_SEG_SIZE_PE='1' LVM2_PVSEG_START='512' LVM2_LV_NAME='usedblocks' LVM2_SEG_START_PE='1' LVM2_SEG_SIZE_PE='233' LVM2_PVSEG_START='1' LVM2_LV_NAME='usedblocks' LVM2_SEG_START_PE='234' LVM2_SEG_SIZE_PE='1' LVM2_PVSEG_START='513' LVM2_LV_NAME='usedblocks' LVM2_SEG_START_PE='235' LVM2_SEG_SIZE_PE='277' LVM2_PVSEG_START='235' Am 03.01.22 um 12:13 schrieb Roland: > thanks! > > any chance to get retrieve this information for automated/script based > processing ? > > roland > > > Am 03.01.22 um 00:12 schrieb Andy Smith: >> Hi Roland, >> >> On Sun, Jan 02, 2022 at 08:00:30PM +0100, Roland wrote: >>> if i have a logical sector/block "x" on a lvm logical volume , is >>> there >>> a way to easily calculate/determine (optimally by script/cli) the >>> corresponding physical sector of the physical device it belongs to and >>> the extent number of the appropiate pv/vg where it resides ? >> lvdisplay --maps /path/to/lv >> >> tells you all the mappings of logical extents within the LV to >> physical extents within the PV. >> >> pvdisplay --units s /dev/yourpv | grep 'PE Size' >> >> tells you the size of a physical extent in sectors. >> >> Between those you can work out the sector number on the physical >> device for a sector number on a logical volume. >> >> Cheers, >> Andy >> >> _______________________________________________ >> linux-lvm mailing list >> [email protected] >> https://listman.redhat.com/mailman/listinfo/linux-lvm >> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ >> _______________________________________________ linux-lvm mailing list [email protected] https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/