HP StorageWorks Storage Mirroring for Linux User's Guide (T2558-96078, February 2008)

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Configuring queuing
There are five queuing parameters available for configuration. Use the get and set commands to view or modify an option.
See
Storage Mirroring Commands on page A-1 for complete command syntax.
 QJournalDir—This is the location where the queue is stored.
 QJournalFileSize—This is the size, in MB, of each queuing transaction log file. By default, the file size is 5 MB.
 QmemoryBufferMax—This is the amount of system memory, in MB, that, when exceeded, will trigger queuing to disk.
This value is dependent on the amount of physical memory available but has a minimum of 32 MB. By default, 128 MB of
memory will be used.
 QJournalSpaceMax—This is the maximum amount of disk space, in MB, in the specified QJournalDir that can be used
for Storage Mirroring queuing. When this limit is reached, Storage Mirroring will automatically begin the auto-disconnect
process. By default, Storage Mirroring will use an unlimited amount of disk space equivalent to 4,294,967,295 MB. This
unlimited setting allows the disk queue usage to automatically expand whenever the available disk space expands. Setting
this value to zero (
0) disables disk queuing.
 QJournalFreeSpaceMin—This is the minimum amount of disk space, in MB, in the specified QJournalDir that must be
available at all times. By default, 50 MB of disk space will always remain free. The QJournalFreeSpaceMin should be less
than the amount of physical disk space minus
QJournalSpaceMax.
 QueueSizeAlertThreshold—This is a percentage that identifies the amount of the queue that must be in use to trigger
an alert message in the Linux system log. By default, the alert will be generated when the queue reaches 50%.
Configuring auto-reconnect
If Storage Mirroring is stopped on a source machine while a Storage Mirroring connection is active, auto-reconnect will
automatically reestablish the connection, without manual intervention by the administrator, when the Storage Mirroring
source is available . When an auto-reconnect is performed, you may want to perform an auto-remirror to guarantee data
integrity. Use the instructions below for both the auto-reconnect and auto-remirror options.
1. To determine the current auto-reconnect setting, use the get command with the AutoReconnect option.
NOTE: The QJournalSpaceMax and QJournalFree SpaceMin settings work in conjunction with each other. For
example, assume your queues are stored on a 10 GB disk with the QJournalSpaceMax set to 10 GB and
the QJournalFreeSpaceMin set to 500 MB. If another program uses 5 GB, Storage Mirroring will only be
able to use 4.5 GB so that 500 MB remains free.
Command GET
Description The Text Client/DTCL sends a request to Storage Mirroring to return the value of a Storage
Mirroring program setting. The setting is retrieved by Storage Mirroring from the registry.
Syntax
GET <option> [machine]
Options  option—See Storage Mirroring Text Client program settings on page 14-11.
 machine—Name of the machine
Examples
 get netport
 get VerifyLogName
 get DefaultAddress
Notes  If you do not specify a machine name, the value from the current source will be returned. If you
have not identified an active source, no data will be returned.
 Machine names that contain non-alphanumeric characters must be enclosed in quotation marks.