Is there something out there for parallel archiving of files?
Tar is great, but I don't use tape archives, and it's more important to me that the archiving happens quickly (with compression like bzip2) since I have smp.
Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. It only takes a minute to sign up.Sign up to join this community
I think you are looking for pbzip2:
PBZIP2 is a parallel implementation of the bzip2 block-sorting file compressor that uses pthreads and achieves near-linear speedup on SMP machines.
Have a look at the project homepage or check your favorite package repository.
7zip can run on multiple threads when given the
-mmt flag, but only when compressing into 7z-archives, which offer great compression but are generally slower than zip to create archives. Do something like this:
7z a -mmt foo.7z /opt/myhugefile.dat
The OP asked about parallel archiving, not parallel compression.
If the source material is coming from a filesystem where different directories/files might be on different disks, or even a single fast disk that exceeds the input speed of the compression tool(s), then could indeed be beneficial to have multiple streams of input going into the compression layers.
The meaningful question becomes, what does the output from a parallel archive look like? It's no longer just a single file descriptor /
stdout, but a file descriptor per thread.
An example of this so far is the parallel dump mode of Postgresql
pg_dump, wherein it dumps to a directory, with threads working over the set of tables to back up (work queue w/ multiple threads consuming the queue).
I'm not sure of any actual parallel archivers that are mainstream. There was a hack for Solaris Tar for use on ZFS: http://www.maier-komor.de/mtwrite.html
There are some dedicated backup tools that successfully run multiple threads, but lots more that just split the workload by directory at a high level.
pigz is a parallel implementation of gzip, but can only really use multiple processors for compression, not decompression.
tar is simply an archive format that is very good at exactly duplicating the files and preserving the directory tree and the original file attributes. TAR is very good for making backups, because everything is preserved. I use
pbzip2 to compress the tar archives I use for system backups with very good results.
this command should do the trick.
tar -cpS "infile" | pbzip2 > "outfile"
pbzip2 can be replaced with a different compression utility, but be warned, LZMA compression (like pxz) uses a TON of RAM when compressing/decompressing large files (I tried to run 8 threads with 8GB of RAM, and pxz started swapping to disk).
Another contender is
lbzip2. It's quite similar to pbzip2