Backup Exec 20.2 Administrator's Guide

To edit disk storage properties

1. On the Storage tab, double-click the storage for which you want to edit properties.
2. In the left pane, click Properties.
3. Edit any of the following options:

   Name	Displays the name of the disk storage. You can edit this field.
   Description	Displays a description of the disk storage. You can edit this field.
   Limit Backup Exec to read-only operations	Prevents Backup Exec from deleting expired backup sets on this disk storage when you reattach the disk storage to the Backup Exec server. Otherwise, Backup Exec's data lifecycle management feature deletes any backup sets that are expired and reclaims the disk space. The default value is No. This option applies only when the disk storage has been detached from the Backup Exec server for the number of days that you specify in the global setting. The default number of days is 14. See How data lifecycle management (DLM) deletes expired backup sets on disk-based storage. See Backup sets . See How to restore data from a reattached or reinserted disk-based storage device.
   Maximum file size	Displays the maximum file size on the disk storage. The data from the backup job is contained in a file on the disk. The default value is 50 GB or the capacity of the disk storage.
   Preallocate disk space incrementally up to the maximum file size	Creates the file when the backup job starts by preallocating space incrementally, according to the size of the increment that you set in Preallocation increment. As the job uses the disk space, more disk space is preallocated up to the maximum file size. When the job completes, the file size is then reduced to the amount of disk space that the job used. For example, if you enable preallocation and set the preallocation increment to 4 GB, then 4 GB of disk space is preallocated when the job starts. After the job uses 4 GB, then Backup Exec allocates another 4 GB. Disk space continues to be preallocated by 4 GB until the job completes. If the job only uses 13 GB of the 16 GB that was allocated, then the file size is reduced to 13 GB. The default value is Disabled.
   Preallocation increment	Displays the amount of disk space by which to increase the file size. The file size increases by this increment as the job requires disk space, up to the maximum file size. The default value is 1 GB.
   Auto detect block and buffer size	Indicates if Backup Exec automatically detects the preferred settings for the block size and buffer size for the disk storage. The default value is Enabled. If you disable this setting, you can then choose the block size and buffer size to use.
   Block size	Displays the size of the blocks of data that are written to new media in this disk storage device if the option Auto detect block and buffer size is disabled. The default is the preferred block size. Some storage devices provide better performance when larger block sizes are used. The preferred block size can range from 512 bytes to 64 kilobytes or larger. If you use a storage device that supports larger block sizes, you can change the block size. However, if the option to change the block size is unavailable, you must configure the device to use a larger size. See the manufacturer's documentation for help in configuring the device. Backup Exec does not ensure that the storage device supports the requested block size. If the requested block size is not supported, it defaults to its standard block size. If the device does not support block size configuration, this option is unavailable.
   Buffer size	Displays the amount of the data that is sent to the disk storage device on each read or write request if the option Auto detect block and buffer size is disabled. The buffer size must be an even multiple of the block size. Depending on the amount of memory in your system, increasing this value may improve storage performance. Each type of storage device requires a different buffer size to achieve maximum throughput. If the preferred block size is greater than 64 KB, the default buffer size is the same as the default block size. If the preferred block size is less than 64 KB, then the default buffer size is 64 KB.
   Low disk space - Critical	Displays the critically low disk space threshold at which you want Backup Exec to send an alert. The color of the capacity bar on the Storage tab turns red to indicate critically low available space. Backup Exec sends alerts when the amount of free disk space drops below the low disk space threshold, and again if it drops below the warning threshold. The amount of free disk space does not include the disk space that is reserved for non-Backup Exec operations. You can change the value of the threshold. This threshold must be less than the warning threshold. The default value is 5%.
   Low disk space - Warning	Displays the low disk space threshold at which you want Backup Exec to send an alert. The color of the capacity bar on the Storage tab turns orange to indicate a low disk space condition. If free disk space drops below the warning threshold to the critical threshold, another alert is sent. The amount of free disk space does not include the disk space that is reserved for non-Backup Exec operations. You can change the value of the threshold. This threshold must be less than the low disk space threshold. The default value is 15%.
   Low disk space	Displays the low disk space threshold at which you want Backup Exec to send an alert. The color of the capacity bar on the Storage tab turns yellow to indicate the first of three low disk space conditions. If free disk space drops below this threshold to the amount that is specified in the warning threshold, another alert is sent. If free disk space drops below the warning threshold to the critical threshold, another alert is sent. The amount of disk space does not include the disk space that is reserved for non-Backup Exec operations. When low disk space reaches this threshold, data lifecycle management immediately searches the device for expired backup sets that it can delete. You can change the value of the threshold. The default value is 25%. See How data lifecycle management (DLM) deletes expired backup sets on disk-based storage.
   Disk space to reserve for non-Backup Exec operations	Displays the amount of disk space to set aside for applications other than Backup Exec. The default value is 10 MB.
   Auto detect settings	Indicates if Backup Exec automatically detects the preferred settings for read and write buffers for the disk storage.
   Buffered read	Indicates the following when the setting is enabled: You do not want Backup Exec to automatically detect settings for this disk storage device. You want this disk storage to allow buffered read, which is the reading of large blocks of data. Enabling buffered reads may provide increased performance.
   Buffered write	Indicates the following when the setting is enabled: You do not want Backup Exec to automatically detect settings for this disk storage device. You want this disk storage to allow buffered write, which is the writing of large blocks of data.
   Concurrent write sessions	Displays the number of concurrent write operations that you want to allow to this disk storage device.

4. Click Apply.