- Enable block suballocation if you are using the traditional NetWare file system. Block suballocation is enabled by default, but can be disabled when the volume is created. If block suballocation has been disabled, enable it using NWCONFIG (NWCONFIG > Standard Disk Options > NetWare Volume Options > select the volume and change the Block Suballocation field to On). Once block suballocation is enabled, it cannot be disabled without recreating the volume.
- Set your file block size to 64 KB if you are using block suballocation (available only in the traditional NetWare file system). The larger block size causes the system to transfer more data at one time and therefore improves performance. Block suballocation prevents unused portions of large blocks from being wasted.
- Keep at least 1000 free blocks on each NetWare volume that has suballocation enabled. Free blocks are disk blocks that have no files stored in them. If the number of free blocks is low, then suballocation goes into an aggressive mode that can cause server utilization to increase.
To find the number of free blocks, in MONITOR select Available Options > Volumes, then highlight the name of the volume you want. Press Tab to expand the information window and note the value of the Free Blocks statistic. To free disk blocks, purge deleted files. See Reference > Utilities Reference > Utilities > PURGE.
- You can save a significant amount of partition space and increase performance by eliminating the Hot Fix redirection area on the partition. However, once Hot Fix is eliminated from a partition, you cannot add it again without first deleting the volumes on the partition. Once Hot Fix is gone, the partition will no longer be fault tolerant, unless the hard disk itself provides a means of fault tolerance. Data on corrupted sectors of the disk won't be redirected to the Hot Fix redirection area. In addition, you will not be able to mirror the partition. Refer to Step 6 of Creating NetWare Disk Partitions for instructions on how to create a partition without the Hot Fix redirection area.
- Turn off Read-After-Write-Verify in MONITOR.
Read-After-Write-Verify is almost always provided by the hard disk itself. Use the Read-After-Write-Verify feature in MONITOR only if your hardware does not provide this feature but does support software-controlled Read-After-Write-Verify.
See Turning Off Read-After-Write Verification.
- If you have a 16-bit disk adapter, make sure you increase the number of reserved buffers below 16 MB. Use the SET command or MONITOR to set the parameter Reserved Buffers Below 16 MB to its upper limit, 300. The parameter is found in MONITOR > Available Options > Server Parameters > Memory. Remember that too many reserved buffers can prevent large volumes from mounting. As soon as possible, upgrade the system to a newer board that can access higher memory.
- Use a driver that supports scatter gather functionality.
- Provide at least one device large enough to hold a core dump of the server's memory. A core dump cannot span devices.
- If a NetWare volume is comprised of two or more segments, each segment should be on a different disk. If the volume is made of more than one segment on one disk, the volume spans between the two segments, slowing performance.
- Make sure that file compression, if enabled, happens only when there is little activity on the server. (File compression is available only on the traditional NetWare file system, not the NSS file system.)
For example, make sure that the Deleted Files Compression Option parameter is not set to 2, which would cause compression whenever a file is deleted but not purged. Make sure that users have not flagged their directories IC, which enables immediate compression. Use SET commands to make sure that compression is scheduled to start and stop at the appropriate times. See the File System category of parameters in Reference > Utilities Reference > Utilities > SET.
- For protection, mirror or duplex the Sys volume, because it contains the core NetWare files. See Mirroring and Duplexing Partitions.
- Keep 10% free space in any NetWare volume, except Sys, for which you should maintain 20% free space.
If the Sys volume fills up or runs out of disk space, the Transaction Tracking System, which protects NDS®, shuts down. This compromises the NDS replicas on the server.
To keep enough free space on volumes, try the following:
- Use MONITOR to check each volume's disk space regularly.
- Use the Volume Low Warning Threshold parameter to specify when you will be warned that a volume is running out of disk space. Set the parameter in MONITOR > Available Options > Server Parameters > File System Parameters.
- Move any user files or print queues to another volume.
- Don't store replicas on servers with low disk space.
- CD-ROM drives can create large index files. Don't use or mount the CD-ROM unless you have enough space.
- Limit the size of auditing files.