Veritas File System 4.1 Release Notes (5900-0592, March 2010)

• Some Disk Quota Operations Do Not Function on NFS
Problem
When VxFS file systems are exported via NFS, quotas on the file system apply to users when
accessing the file system from NFS clients. However, the HP-UX quota commands on the
NFS client cannot be used to edit quotas.
Workaround
The VxFS quota commands can be used only on the server to edit quotas.
• Large Directories May Degrade Performance
Problem
Creating more that 100,00 files in the same directory degrades VxFS performance.
Workaround
To maximize VxFS performance, do not exceed 100,000 files in the same directory. Use
multiple directories instead.
• System Hang Occur on Systems With Less Cache Memory
Problem
Low-memory Systems May Hang Due to VxFS Memory Consumption.
Wokaround
VxFS consumes a fixed percentage of memory based on the default values of tunables, such
as vx_ninode and vxfs_bc_bufhwm. For example, VxFS consumes nearly 10% of total
physical memory for the default value of vx_ninode. If the system has 512 MB of memory,
VxFS will require up to 52 MB to store the VxFS inode cache. Therefore it is necessary to
tune the tunables according to the type of load on the system.
As a workaround to this problem, lower the values of vx_ninode and vxfs_bc_bufhwm
to limit VxFS memory consumption.
• Full or Fragmented File System Cannot Be Resized
Problem
In some circumstances, the fsadm command cannot resize a 100% full file system due to
lack of space for updating structural information. If a file system is busy or too fragmented,
the resize operation fails.
Workaround
Free up space by deleting files you do not need.
• Data Integrity Issues with Disks and Disk Arrays with Write-back Caches
Problem
Disk drives configured for use with a write-back cache, or disk arrays configured with a
volatile write-back cache, exhibit data integrity problems. The problems occur after a power
failure, SCSI bus reset, or other events in which the cached data is lost before being written
to disk.
Workaround
As a workaround for this problem you must disable the write-back cache.
• The fsadm Command Cannot Truncate a Directory
The fsadm command cannot truncate a directory if it has only one extent that is more than
two blocks in length, even if all the directory entries are deleted.
Workaround
The workaround information is available on the version of Veritas File System Release Notes
available at http://docs.hp.com.
Known Problems And Workaround 15