Installation guide

• UNIX File System
In this release, the UNIX File System (UFS) file size is limited by the
amount of space that can be addressed by the kernel buf structure. The
buf.b_blkno structure field, defined as daddr_t, is a 32-bit signed
value, and specifies the block/sector offset within a disk partition. The
DEV_BSIZE, block or sector size, is 512 bytes. Theoretically, a UFS file
system could be 1 TB (2
13
*2
9
); however, Tru64 UNIX supports only
128 GB. The maximum LSM logical volume size also limits a UFS file
system and file size.
Tru64 UNIX supports up to 2,147,483,647 UNIX File System (UFS) and
Memory File System (MFS) mounts. The max-ufs-mounts attribute
controls the maximum number of UFS and MFS mounts. The default
value is 1000.
• CD–ROM File System
The size of ISO 9660 CD–ROM File System (CDFS) files and file
systems is limited by the CD–ROM media on which they reside.
Currently, the CD–ROM media supports approximately 600 MB.
However, Tru64 UNIX is able to support larger ISO 9660 file systems
on other media.
This release supports a maximum of 512 CDFS mounts.
• Sparse files
Tru64 UNIX supports sparse files on AdvFS and UFS; therefore, the
logical size of a file (that is, the offset to the last data actually present)
can exceed the size of the file system in which it resides. The maximum
sizes for sparse files are as follows:
– AdvFS – 2
44
− 512K
– UFS – 2
44
− 8K
• Network File System
In this release, the theoretical maximum sizes of files that are accessible
through Network File System (NFS) Version 2 and Version 3 are as
follows:
– NFS Version 2 – (2 GB – 1 byte)
– NFS Version 3 – 18 exabytes (2
64
− 1)
However, Tru64 UNIX supports the following maximum file sizes:
– NFS Version 2 – 2GB
– NFS Version 3 – 512 GB
In addition, an NFS file system is always limited by the size of the local
file system that is being exported.
A–6 System Limits