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BaculaFSBaculaFS - Exposes the Bacula1 catalog and storage as a Filesystem in USErspace (FUSE). Copyright © 2009, 2010 Avi Rozen <avi.rozen@gmail.com> IntroductionBaculaFS is a tool, developed independently of Bacula, that represents the Bacula catalog and backup storage media as a read-only filesystem in userspace. BaculaFS is specifically designed to cater for the following use-cases:
Note that BaculaFS is a maintenance tool - its operation may interfere with the normal operation of a live Bacula setup (see the Limitations section below). RequirementsBaculaFS has been tested with the following set of required software packages:
BaculaFS requires the following in order to function:
InstallationExtract the source code archive to a temporary directory, cd to this directory and run python setup.py install Usagebaculafs [mountpoint] [options]
Options:
--version show program's version number and exit
-h, --help show this help message and exit
-o opt,[opt...] mount options
-o driver=mysql|postgresql|sqlite3
database driver [default: sqlite3]
-o host=HOST database server address [default: localhost]
-o port=PORT database server port
-o database=PATH database name [default: bacula]
-o username=USERNAME database user name [default: bacula]
-o password=PASSWORD database password (use '-o password= ' to get a
password prompt; if not provided, the password is
read from the DATABASE_PASSWORD environment
variable)
-o conf=PATH storage daemon configuration file [default:
/etc/bacula/bacula-sd.conf]
-o client=CLIENT file daemon name
-o fileset=FILESET backup fileset
-o device=DEVICE storage device name [default: FileStorage]
-o datetime='YYYY-MM-DD hh:mm:ss'
snapshot date/time [default: now]
-o recent_job select contents of most recent job only [default:
False]
-o joblist='JOBID1 JOBID2 ...'
select contents of specified list of jobs
-o cleanup clean cache directory upon umount [default: False]
-o move_root make absolute path symlinks point to path under
mount point [default: False]
-o prefetch_attrs read and parse attributes for all files upon
filesystem initialization [default: False]
-o prefetch_symlinks extract all symbolic links upon filesystem
initialization (implies prefetch_attrs) [default:
False]
-o prefetch_regex=REGEX
extract all objects that match REGEX upon
filesystem initialization (implies prefetch_attrs)
-o prefetch_recent extract contents of most recent non-full job upon
filesystem initialization (implies
prefetch_symlinks) [default: False]
-o prefetch_diff=PATH extract files that do not match files at PATH
(hint: speeds up rsync; implies prefetch_symlinks)
-o prefetch_difflist=DIFFLIST
extract files that do not match files in DIFFLIST
(list line format: 'Day Mon DD hh:mm:ss YYYY PATH';
use '-' to read from standard input; hint: format
matches output of 'duplicity list-current-files -v0
target_url'; implies prefetch_symlinks)
-o prefetch_list=LIST extract files that match files in LIST (list should
contains one absolute file path per line; use '-'
to read from standard input; implies
prefetch_symlinks)
-o prefetch_everything
extract everything upon filesystem initialization
(complete restore to cache) [default: False]
-o batch_list list files to be prefetched and exit [default:
False]
-o batch_bsr dump contnets of bsr file for extracting prefetched
files and exit [default: False]
-o batch_extract extract prefetched files to mount point and exit
[default: False]
-o user_cache_path=PATH
user specified cache path (hint: combine this with
one of the prefetch options) [default: none]
-o logging=debug|info|warning|critical|error
logging level [default: info]
-o syslog log to both syslog and console [default: False]
FUSE options:
-d -o debug enable debug output (implies -f)
-f foreground operation
-s disable multi-threaded operation
-o allow_other allow access to other users
-o allow_root allow access to root
-o nonempty allow mounts over non-empty file/dir
-o default_permissions enable permission checking by kernel
-o fsname=NAME set filesystem name
-o subtype=NAME set filesystem type
-o large_read issue large read requests (2.4 only)
-o max_read=N set maximum size of read requests
-o hard_remove immediate removal (don't hide files)
-o use_ino let filesystem set inode numbers
-o readdir_ino try to fill in d_ino in readdir
-o direct_io use direct I/O
-o kernel_cache cache files in kernel
-o [no]auto_cache enable caching based on modification times (off)
-o umask=M set file permissions (octal)
-o uid=N set file owner
-o gid=N set file group
-o entry_timeout=T cache timeout for names (1.0s)
-o negative_timeout=T cache timeout for deleted names (0.0s)
-o attr_timeout=T cache timeout for attributes (1.0s)
-o ac_attr_timeout=T auto cache timeout for attributes (attr_timeout)
-o intr allow requests to be interrupted
-o intr_signal=NUM signal to send on interrupt (10)
-o modules=M1[:M2...] names of modules to push onto filesystem stack
-o max_write=N set maximum size of write requests
-o max_readahead=N set maximum readahead
-o async_read perform reads asynchronously (default)
-o sync_read perform reads synchronously
-o atomic_o_trunc enable atomic open+truncate support
-o big_writes enable larger than 4kB writes
-o no_remote_lock disable remote file locking
Module options:
[subdir]
-o subdir=DIR prepend this directory to all paths (mandatory)
-o [no]rellinks transform absolute symlinks to relative
[iconv]
-o from_code=CHARSET original encoding of file names (default: UTF-8)
-o to_code=CHARSET new encoding of the file names (default: UTF-8)OperationInitializationBaculaFS starts by running several SQL queries against the Bacula catalog. This is done to determine the list of files that belong to the most recent backup for a given client and fileset. BaculaFS can also be told to represent a backup snapshot corresponding to a specified date and time, or a list of backup job ids. Following this, BaculaFS may run bextract once to prefetch and cache symbolic links and actual file contents, depending on user specified command line options. At this point the filesystem is ready. CacheOpening a file for reading causes BaculaFS to run bextract in order to extract the file from the storage device. If this operation succeeds, the file is cached for subsequent read operations. Bacula storage is not designed for random access file retrieval, so it is important to select a suitable cache prefetch strategy beforehand. Running bextract once, during filesystem initialization, to extract several files, is much more efficient than running it several times to extract each individual file, when accessed at a later stage. For example:
The cache may be cleaned up automatically upon un-mounting the filesystem, with -o cleanup. It may also be reused between mount operations with -o user_cache_path. Batch ModeBaculaFS may be used in batch mode with -o batch_extract in order to extract files from the Bacula storage device and then exit without mounting the filesystem. The mountpoint specified at the command line is then treated as the destination directory for extracted files. The list of files, to be extracted in batch mode, is determined by the various cache prefetch options, and may be dumped with -o batch_list. The bootstrap file that is generated, in order to extract the files, can also be dumped to standard output with -o batch_bsr. Extended AttributesBaculaFS uses extended file attributes to expose Bacula specific information for each file in the filesystem. These extended attributes are all grouped in the user.baculafs namespace: user.baculafs.FileIndex user.baculafs.JobId user.baculafs.LStat user.baculafs.MD5 Note that user.baculafs.MD5 shows whatever digest Bacula was configured to calculate for the file, be it MD5, SHA1, SHA256 or SHA512. The root directory has several more attributes, that expose filesystem instance-specific information: user.baculafs.cache_prefix user.baculafs.client user.baculafs.datetime user.baculafs.fileset user.baculafs.joblist and several more attributes for monitoring the file extraction process: user.baculafs.bextract.failures user.baculafs.bextract.path user.baculafs.bextract.pending user.baculafs.bextract.retries user.baculafs.bextract.state user.baculafs.bextract.volume Missing VolumesIf the storage device is a tape drive then it's possible that BaculaFS will attempt to retrieve a file from a volume that's on an unmounted tape. BaculaFS will then set user.baculafs.bextract.state to *user intervention required*, and will wait for user intervention. The user should then mount the tape containing the missing volume and set the state to run, to make BaculaFS retry the operation: attr -s baculafs.bextract.state -V run <mount-point> Please note that this feature has undergone only rudimentary testing. Expect breakage. ExamplesMount the most recent backup snapshot for Bacula client client-fd and fileset client-fileset; SQLite database backend (default): baculafs -o client=client-fd,fileset=client-fileset /path/to/mount/point Mount the contents of the specified list of backup jobs; MySQL database backend; prompt for password and prefetch to cache all symbolic links: baculafs -o joblist='1001 1003',client=client-fd,fileset=client-fileset \
-o driver=mysql,password=,prefetch_symlinks /path/to/mount/pointMount the contents of the most recent backup job only: baculafs -o recent_job,client=client-fd,fileset=client-fileset /path/to/mount/point Mount the contents of the fileset snapshot before the specified date/time: baculafs -o datetime='2009-05-23 00:00:00' \
-o client=client-fd,fileset=client-fileset /path/to/mount/pointAllow other users to access filesystem, set logging level to debug and stay in foreground, so that bextract messages may be examined; assume a single Bacula fileset is defined for client client-fd: baculafs -f -o allow_other,client=client-fd,logging=debug /path/to/mount/point Prefetch to cache files that do not exist, or whose modification time or size differ from those at the specified directory (i.e. files that would be sent to that directory using rsync); and cleanup cache after un-mounting: baculafs -o prefetch_diff=/path/to/rsync/target,cleanup \
-o client=client-fd /path/to/mount/pointBatch update a snapshot of the current files in backup (the filesystem is not mounted): baculafs -o batch_extract,prefetch_diff=/path/to/snapshot,cleanup \
-o client=client-fd /path/to/snapshot/(this is not as accurate as mounting the filesystem, like in the previous example, and then updating the snapshot with rsync - but it is faster). LimitationsCommon ProblemsBaculaFS will abort if no backup job was run for the client/fileset combination selected by the user. BaculaFS will abort if the target mount point is in use. Note, however, that mount point availability is checked by FUSE only after the (potentially lengthy) initialization of BaculaFS. Browsing a BaculaFS mount point with a file manager like Nautilus is liable to be very slow. This is because the file manager reads data from each file being listed, in order to determine its type, generate a thumbnail etc. This, in turn, triggers BaculaFS to extract the files, one at a time, from the Bacula storage device to its cache directory. LockingAccess to the storage device by different instances of BaculaFS is serialized by locking the storage daemon configuration file. This means that you can mount several views of the backup catalog (e.g. accessing backup snapshots of different clients or snapshots from the same client but from different dates). There are at least two issues with this locking mechanism that you should note:
Unsupported FeaturesBaculaFS depends on bextract and thus inherits its limitations:
ChangelogVersion 0.1.7 (2010-12-30)
Version 0.1.6 (2010-09-19)
Version 0.1.5 (2010-07-06)
Version 0.1.4 (2010-02-07)
Version 0.1.3 (2010-01-13)
Version 0.1.2 (2010-01-13)
Version 0.1.1 (2010-01-07)
Version 0.1.1 (2010-01-06)
BugsPlease report problems via the BaculaFS issue tracking system: http://code.google.com/p/baculafs/issues/list CreditsBaculaFS contains SQL queries that were adapted from Bacula, Copyright © 2000-2010 Free Software Foundation Europe e.V. LicenseBaculaFS is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/. 1Bacula is a registered trademark of Kern Sibbald. |
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