Re: query btrfs creation options
I think actual userland tools should be able to do what you want; leafsize, nodesize, sectorsize: btrfs-show-super /dev/dm-6 label: blkid /dev/dm-6 data, metadata: btrfs filesystem df / # btrfs-show-super /dev/dm-6 superblock: bytenr=65536, device=/dev/dm-6 - csum 0xba41e65b [match] bytenr 65536 flags 0x1 magic _BHRfS_M [match] fsid 456e363c-650e-4c29-898c-b2b65bf9c3b3 label p4-btrfs2 generation 253003 root 664749473792 sys_array_size 97 chunk_root_generation 218142 root_level 1 chunk_root 131072 chunk_root_level 0 log_root 0 log_root_transid 0 log_root_level 0 total_bytes 536869732352 bytes_used 441861300224 sectorsize 4096 nodesize 65536 leafsize 65536 stripesize 4096 root_dir 6 num_devices 1 compat_flags 0x0 compat_ro_flags 0x0 incompat_flags 0x29 csum_type 0 csum_size 4 cache_generation 253003 dev_item.uuid 5a5802fb-5012-4bae-897e-388754b5ed08 dev_item.fsid 456e363c-650e-4c29-898c-b2b65bf9c3b3 [match] dev_item.type 0 dev_item.total_bytes 536869732352 dev_item.bytes_used 446689181696 dev_item.io_align 4096 dev_item.io_width 4096 dev_item.sector_size 4096 dev_item.devid 1 dev_item.dev_group 0 dev_item.seek_speed 0 dev_item.bandwidth 0 dev_item.generation 0 On Wed, Apr 24, 2013 at 4:00 PM, Rich Turner rtur...@storix.com wrote: i am looking for a way to query btrfs filesystems for all options used to create the filesystem (i.e. data, leafsize, label, metadata, nodesize, sectorsize) in an effort to be able to record this information and be able to recreate the filesystem with the same attributes if necessary. i see there is a feature request for creating an api/library that may provide this functionality, but i am unable to find any suitable userspace command that provides the information. -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: query btrfs creation options
On Wed, Apr 24, 2013 at 01:00:02PM -0700, Rich Turner wrote: i am looking for a way to query btrfs filesystems for all options used to create the filesystem (i.e. data, leafsize, label, metadata, nodesize, sectorsize) in an effort to be able to record this information and be able to recreate the filesystem with the same attributes if necessary. the 'file' utility is able to give you the leaf/node/sector numbers $ file -s /dev/sda5 /dev/sda5: BTRFS Filesystem sectorsize 4096, nodesize 4096, leafsize 4096) I don't have the label set, but it is printed if set. The raid profiles can be obtained from 'btrfs fi df', this should be enough to recreate the fs. i see there is a feature request for creating an api/library that may provide this functionality, but i am unable to find any suitable userspace command that provides the information. 'file' parses the superblock directly, but we could enhance the ioctl BTRFS_IOC_FS_INFO to get it in an api-friendly way. david -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
