This patch adds the --sparse-block option. Andrea Righi writes: In some filesystems, typically optimized for large I/O throughputs (like IBM GPFS, IBM SAN FS, or distributed filesystems in general) a lot of lseek() operations can strongly impact on performances. In this cases it can be helpful to enlarge the block size used to handle sparse files directly from a command line parameter. For example, using a sparse write size of 32KB, I've been able to increase the transfer rate of an order of magnitude copying the output files of scientific applications from GPFS to GPFS or GPFS to SAN FS. -Andrea To use this patch, run these commands for a successful build: patch -p1 0) { int r1; if (sparse_files > 0) { - int len1 = MIN(len, SPARSE_WRITE_SIZE); + int len1 = MIN(len, sparse_files_block_size); r1 = write_sparse(f, use_seek, offset, buf, len1); offset += r1; } else { diff --git a/options.c b/options.c --- a/options.c +++ b/options.c @@ -76,6 +76,7 @@ int remove_source_files = 0; int one_file_system = 0; int protocol_version = PROTOCOL_VERSION; int sparse_files = 0; +long sparse_files_block_size = SPARSE_WRITE_SIZE; int preallocate_files = 0; int do_compression = 0; int do_compression_level = CLVL_NOT_SPECIFIED; @@ -692,6 +693,7 @@ static struct poptOption long_options[] = { {"sparse", 'S', POPT_ARG_VAL, &sparse_files, 1, 0, 0 }, {"no-sparse", 0, POPT_ARG_VAL, &sparse_files, 0, 0, 0 }, {"no-S", 0, POPT_ARG_VAL, &sparse_files, 0, 0, 0 }, + {"sparse-block", 0, POPT_ARG_LONG, &sparse_files_block_size, 0, 0, 0 }, {"preallocate", 0, POPT_ARG_NONE, &preallocate_files, 0, 0, 0}, {"inplace", 0, POPT_ARG_VAL, &inplace, 1, 0, 0 }, {"no-inplace", 0, POPT_ARG_VAL, &inplace, 0, 0, 0 }, @@ -2684,6 +2686,12 @@ void server_options(char **args, int *argc_p) args[ac++] = arg; } + if (sparse_files_block_size) { + if (asprintf(&arg, "--sparse-block=%lu", sparse_files_block_size) < 0) + goto oom; + args[ac++] = arg; + } + if (io_timeout) { if (asprintf(&arg, "--timeout=%d", io_timeout) < 0) goto oom; diff --git a/rsync.1.md b/rsync.1.md --- a/rsync.1.md +++ b/rsync.1.md @@ -379,6 +379,7 @@ detailed description below for a complete description. --super receiver attempts super-user activities --fake-super store/recover privileged attrs using xattrs --sparse, -S turn sequences of nulls into sparse blocks +--sparse-block=SIZE set block size used to handle sparse files --preallocate allocate dest files before writing them --write-devices write to devices as files (implies --inplace) --dry-run, -n perform a trial run with no changes made @@ -1477,6 +1478,18 @@ your home directory (remove the '=' for that). opposed to allocated sequences of null bytes) if the kernel version and filesystem type support creating holes in the allocated data. +0. `--sparse-block=SIZE` + + Change the block size used to handle sparse files to SIZE bytes. This + option only has an effect if the `--sparse` (`-S`) option was also + specified. The default block size used by rsync to detect a file hole is + 1024 bytes; when the receiver writes data to the destination file and + option `--sparse` is used, rsync checks every 1024-bytes chunk to detect if + they are actually filled with data or not. With certain filesystems, + optimized to receive data streams for example, enlarging this block size + can strongly increase performance. The option can be used to tune this + block size. + 0. `--dry-run`, `-n` This makes rsync perform a trial run that doesn't make any changes (and diff -Nurp a/rsync.1 b/rsync.1 --- a/rsync.1 +++ b/rsync.1 @@ -455,6 +455,7 @@ detailed description below for a complet --super receiver attempts super-user activities --fake-super store/recover privileged attrs using xattrs --sparse, -S turn sequences of nulls into sparse blocks +--sparse-block=SIZE set block size used to handle sparse files --preallocate allocate dest files before writing them --write-devices write to devices as files (implies --inplace) --dry-run, -n perform a trial run with no changes made @@ -1541,6 +1542,16 @@ NTFS, etc.), this option may have no pos If combined with \fB\-\-sparse\fP, the file will only have sparse blocks (as opposed to allocated sequences of null bytes) if the kernel version and filesystem type support creating holes in the allocated data. +.IP "\fB\-\-sparse-block=SIZE\fP" +Change the block size used to handle sparse files to SIZE bytes. This +option only has an effect if the \fB\-\-sparse\fP (\fB\-S\fP) option was also +specified. The default block size used by rsync to detect a file hole is +1024 bytes; when the receiver writes data to the destination file and +option \fB\-\-sparse\fP is used, rsync checks every 1024-bytes chunk to detect if +they are actually filled with data or not. With certain filesystems, +optimized to receive data streams for example, enlarging this block size +can strongly increase performance. The option can be used to tune this +block size. .IP "\fB\-\-dry-run\fP, \fB\-n\fP" This makes rsync perform a trial run that doesn't make any changes (and produces mostly the same output as a real run). It is most commonly used diff -Nurp a/rsync.1.html b/rsync.1.html --- a/rsync.1.html +++ b/rsync.1.html @@ -370,6 +370,7 @@ detailed description below for a complet --super receiver attempts super-user activities --fake-super store/recover privileged attrs using xattrs --sparse, -S turn sequences of nulls into sparse blocks +--sparse-block=SIZE set block size used to handle sparse files --preallocate allocate dest files before writing them --write-devices write to devices as files (implies --inplace) --dry-run, -n perform a trial run with no changes made @@ -1420,6 +1421,18 @@ opposed to allocated sequences of null b filesystem type support creating holes in the allocated data.

+
--sparse-block=SIZE
+

Change the block size used to handle sparse files to SIZE bytes. This +option only has an effect if the --sparse (-S) option was also +specified. The default block size used by rsync to detect a file hole is +1024 bytes; when the receiver writes data to the destination file and +option --sparse is used, rsync checks every 1024-bytes chunk to detect if +they are actually filled with data or not. With certain filesystems, +optimized to receive data streams for example, enlarging this block size +can strongly increase performance. The option can be used to tune this +block size.

+
+
--dry-run, -n

This makes rsync perform a trial run that doesn't make any changes (and produces mostly the same output as a real run). It is most commonly used