.\" -*- nroff -*- .\" Copyright 2008 by Sun Microsystems. All Rights Reserved. .\" This file may be copied under the terms of the GNU Public License, v2. .\" .TH llbackup 8 "2008 Mar 15" Lustre "System management commands" .SH NAME llbackup \- backup a list of files, optionally from multiple nodes at once .SH SYNOPSIS .B llbackup -c .RB [ -hjvxz "] [" -C .IR directory ] .RB [ -e .IR rsh ] .RB [ -i .IR inputlist ] .RB [ -l .IR logdir ] .RB [ -n .IR nodes ] .RB [ -s .IR splitmb ] .RB [ -S .IR splitcount ] .RB [ -T .IR tar ] .BI -f outputfilebase .br .B llbackup .RB { -x | -t } .RB [ -chjvz "] [" -C .IR directory ] .RB [ -e .IR rsh ] .RB [ -l .IR logdir ] .RB [ -n .IR nodes ] .RB [ -T .IR tar ] .BI -f tarfilelist .SH DESCRIPTION .B llbackup takes a list of files to backup or restore, either from standard input, or from a list of files supplied as a parameter and produces one or more archive files containing the files. .B llbackup uses the .BR tar (1) or .BR htar (1) programs to produce archive files, and has many of the same options (though not identical in some cases). The reason for using llbackup instead of those programs directly is that llbackup can run in parallel on multiple nodes to do high-speed backups on clustered or distributed filesystems and will split the work among multiple client nodes to increase performance. .br The archive files produced by .B llbackup are identical to normal tar files (having been created by the local tar command) and can be extracted or listed by .B tar directly. .br The clients will pause and print status messages if they think there is not enough free space in the output directory to avoid running out of space. Backup tarfiles should be moved to offline storage or otherwise purged to allow the backups to continue. If the client is doing a restore it will similarly pause and print status messages if the tarfile it was asked to restore is not available on that node. .SH OPERATIONS The following options control what operation .B llbackup will perform: .TP .B -c create archive. This is the default operation if no other is given. .TP .B -x extract tarfiles from the .I tarfilelist given to .B -f instead of backing them up. .TP .B -t list table of contents of the .I tarfilelist given by .BR -f . .SH OPTIONS .TP .BI -C directory change the backup command to run in .I directory instead of the current working directory so filenames given in the input file are backed up or restored relative to .IR directory . Note that this affects all pathname components used during backup and restore so the .I inputlist and .I outputbase should be specified by absolute pathname if they are not also in .IR directory . .TP .BI -e rsh specify the passwordless remote shell command (default .BR ssh (1)). .TP .BI -f outputbase specify base output filename for backup tar archives, to which a suffix will be appended to ensure that multiple clients doing backup into the same directory do not have conflicting filenames. The .I outputbase file can be a tape or disk device, but must be the same device on each client running the backup, in which case only a single process can run on each client. Specifying .B - means write to standard output. .TP .BI -f tarfilelist specify a file containing a list of tarfiles, one per line, to restore or list the table of contents of. Specifying .B - means read the list of tarfiles from standard input. The .I tarfilelist can also be a tape or disk device, but since the individual tarfiles are sent to individual clients, the same files must be accessible on all clients. .TP .B -h print this help message and exit. Use .B -x .B -h or .B -t .B -h to get the help options for restore or list operations. .TP .BI -i inputlist list of files to backup when creating an archive. If no .B -i option is specified or if .I inputlist is - then the list of files to back up is read from standard input. The input file list is a list of pathnames, one file per line, as generated by .BR find (8), .BR "lfs find" (8), or .BR e2scan (8) for example. For restore this option is currently unused. .TP .B -j use .BR bzip2 (1) compression on input or output tar file(s). This option is not currently supported by the underlying .BR htar (8) implementation. .TP .BI -l logdir directory for output logs. .TP .BI -n nodes comma-separated list of client nodes to run backups. It is possible to specify the same client node multiple times in order to have multiple instances of the backup or restore running in parallel on that node. This is useful to maximize the bandwidth of the backup or restore process and avoid client nodes underutilizing their bandwidth while generating file lists or compressing files. .TP .BI -s splitmb target size for backup chunks in megabytes (default 8192MiB). Increasing this size can improve performance and compression ratios, but may cause underutilization of clients if the files are not evenly distributed. This option has no meaning for restore or list operations. .TP .BI -S splitcount number of files sent to each client before sending files to the next client (default 200). Increasing the .I splitcount keeps more related files together in individual tar files (meaning fewer archives need to be processed when restoring files for a particular subdirectory), but can lead to performance imbalance if files vary greatly in size and one client has to back up many of them due to proximity of filenames in the input list, while other clients back up smaller files. Decreasing the .I splitcount means a more uniform distribution of files and usage among clients, but means nearly every archive will have to be extracted to get only a subset of files needed. This option has no meaning for restore or list operations. .TP .BI -T tar specify the backup command (default tar). Optionally the .BI htar (8) command can be used to back up directly to an HPSS archive, if available. .TP .B -v be verbose - list all files being processed. By default, individual files being backed up or restored are only reported in the log files because they would all be intermixed coming from multiple clients in parallel and the overall progress would be hard to determine. .TP .B -V print version number and exit. .TP .B -z use gzip compression on input or output tar file(s). This option is not currently supported by the underlying .BR htar (8) implementation. .SH EXAMPLES .TP .B lfs find /home -mtime -7 | llbackup -c -n c1,c2 -f /bkup/bk2008-03-15 Create a backup of the .B /home filesystem finding files modified in the last 7 days, compress the output using .B gzip and run on client nodes .B c1 nodes, putting the output tar files into the .B /bkup directory using filenames starting with .BR bk2008-03-15 . .TP .B find /bkup -name bk2007-11-28* | llbackup -x -n c1,c1,c2,c2 -C /tmp -f- Restore .B gzip compressed files from the .B bk2007-11-28 backup from the .B /bkup directory, using two restore processes on each of the client nodes .B c1 and .BR c2 , reading the list of tar files to restore from standard input and restoring into the .B /tmp directory. .SH BUGS It is currently not possible to extract only a subset of files from the tarfiles. If that is necessary, then tar should be run directly on the individual tar files after checking in the backup logs which tarfiles have the relevant files. .SH SEE ALSO .BR lustre (7), .BR tar (8), .BR htar (8), .BR ssh (1), .BR rsh (1), .BR find (1), .BR lfs "(1) " find , .BR e2scan (8).
