HP StorageWorks Scalable File Share - Manual (Page 353)

File system default stripe size and client page size E–3
E.6 File system default stripe size and client page size
The stripe size that you set as the default for files in a file system must be a minimum of 4MB and must also
be a multiple of the largest page size on the client nodes that will be mounting the file system.
Page sizes are 4KB on 32–bit systems; on 64–bit systems, page sizes are 4KB, 8KB, or 16KB.
If the file system default stripe size is not a multiple of the page size on a client node that is accessing the
file system, the following error may be reported on the console of the client node:
kernel: LustreError: 3748:(osc_request.c:783:osc_brw_prep_request())
ASSERTION((pg->off & ~PAGE_MASK) + pg->count <= PAGE_SIZE) failed
The stripe size of newly created files can be set on a file-by-file basis to a value other than the default stripe
size.
E.7 File stripe size and client page size
The stripe size of newly created files can be set on a file-by-file basis to a value other than the default stripe
size associated with the file system. However, the file stripe size must be a multiple of the largest possible
page size on any client node that will access the file. The largest page size supported on Lustre client nodes
is 64KB (for ia64), so that any file stripe size specified must be a multiple of 64KB. This rule also applies to
the default stripe size attribute on a directory.
The
setstripe
command has been modified to print the following warning if you attempt to set a file
stripe size that does not conform to this rule:
error: stripe_size must be an even multiple of 65536 bytes.
If you ignore the warning, the client node may panic with an
LBUG
error when I/O operations to the file or
directory are attempted.
Note that this rule applies to individual files and not to default file system settings, which are described in
Section 5.1.4 and Section 5.2.2.
For more information on file striping, refer to the HP StorageWorks Scalable File Share Client Installation
and User Guide.