From f771a299036e22952ff754889aa592c6116cf031 Mon Sep 17 00:00:00 2001 From: Andreas Dilger Date: Thu, 16 Dec 2010 17:17:22 -0700 Subject: [PATCH] b=21244 add man page for ll_decode_filter_fid tool Add man page for new ll_decode_filter_fid(8) tool. Add references to lustre(7) man page. --- lustre/doc/ll_decode_filter_fid.8 | 59 +++++++++++++++++++++++++++++++++ lustre/doc/ll_recover_lost_found_objs.8 | 4 ++- lustre/doc/lustre.7 | 13 +++++++- 3 files changed, 74 insertions(+), 2 deletions(-) create mode 100644 lustre/doc/ll_decode_filter_fid.8 diff --git a/lustre/doc/ll_decode_filter_fid.8 b/lustre/doc/ll_decode_filter_fid.8 new file mode 100644 index 0000000..a436a52 --- /dev/null +++ b/lustre/doc/ll_decode_filter_fid.8 @@ -0,0 +1,59 @@ +.TH ll_decode_filter_fid 1 "Dec 15, 2010" Lustre "utilities" +.SH NAME +ll_decode_filter_fid \- display Lustre Object ID and MDT parent FID +.SH SYNOPSIS +.B ll_decode_filter_fid +.I object_file +.RI [ "object_file ..." ] +.br +.SH DESCRIPTION +.B ll_decode_filter_fid +decodes and prints the Lustre OST object ID and MDT FID and stripe index +for the specified OST object(s), which is stored in the "trusted.fid" +attribute on each OST object. This is accessible to +.B ll_decode_filter_fid +when the OST filesystem is mounted locally as type ldiskfs for maintenance. +.PP +The "trusted.fid" extended attribute is stored on each OST object when it +is first modified (data written or attributes set) and is not accessed or +modified by Lustre after that time. +.PP +The OST object ID (objid) is useful in case of OST directory corruption, +though normally the +.BR ll_recover_lost_found_objs (8) +utility is able to reconstruct the entire OST object directory hierarchy. +The MDS FID can be useful to determine which MDS inode an OST object +is (or was) used by. The stripe index can be used in conjunction with +other OST objects to reconstruct the layout of a file even if the MDT +inode was lost. +.SH EXAMPLE +.fi +root@oss1# cd /mnt/ost/lost+found +.fi +root@oss1# ll_decode_filter_fid #12345[4,5,8] +.fi +#123454: objid=690670 seq=0 parent=[0x751c5:0xfce6e605:0x0] +.fi +#123455: objid=614725 seq=0 parent=[0x18d11:0xebba84eb:0x1] +.fi +#123458: objid=533088 seq=0 parent=[0x21417:0x19734d61:0x0] +.PP +This shows that the 3 files in lost+found have decimal object IDs 690670, +614725, and 533088, respectively. The object sequence number (formerly +object group) is 0 for all current OST objects. +.PP +The MDT parent inode FIDs are hexdecimal numbers of the form +sequence:oid:idx. Since the sequence number is below 0x100000000 in +all these cases, the FIDs are in the IGIF (legacy Inode and Generation +In FID) namespace and are mapped directly to the MDT inode = seq and +generation = oid values, so the MDT inodes are +0x751c5, 0x18d11, and 0x21417 respectively. For objects with MDT parent +sequence numbers above 0x200000000, this indicates that the FID needs +to be mapped via the MDT Object Index (OI) file on the MDT to determine +the internal inode number. +.PP +The idx field shows the stripe number of this OST object in the Lustre +RAID-0 striped file. +.SH SEE ALSO +.BR lustre (7), +.BR ll_recover_lost_found_objs (8) diff --git a/lustre/doc/ll_recover_lost_found_objs.8 b/lustre/doc/ll_recover_lost_found_objs.8 index 717c2ef..8c981bb 100644 --- a/lustre/doc/ll_recover_lost_found_objs.8 +++ b/lustre/doc/ll_recover_lost_found_objs.8 @@ -22,4 +22,6 @@ Set lost+found directory path. .SH EXAMPLE .fi ll_recover_lost_found_objs -d /mnt/ost/lost+found -.fi +.SH SEE ALSO +.BR lustre (7), +.BR ll_decode_filter_fid (8) diff --git a/lustre/doc/lustre.7 b/lustre/doc/lustre.7 index 81fb408..730ba74 100644 --- a/lustre/doc/lustre.7 +++ b/lustre/doc/lustre.7 @@ -71,4 +71,15 @@ http://downloads.lustre.org/ .BR mount.lustre (8), .BR lctl (8), .BR lfs (1), -.BR liblustreapi (7) +.BR lfs_migrate (1), +.BR liblustreapi (7), +.BR l_getgroups (8), +.BR llstat (8), +.BR ll_recover_lost_found_objs (8), +.BR llverdev (8), +.BR lst (8), +.BR llobdstat (8), +.BR ll_decode_filter_fid (8), +.BR llog_reader (8), +.BR lshowmount (8), +.BR lustre_rsync (8) -- 1.8.3.1