HP StorageWorks Scalable File Share - Manual (Page 115)

Modifying file system attributes 5–31
4. Select the
Add OSTs
option, as follows:
Enter your choice [c]: 1
You are then prompted to select and configure the new OST services for the file system; the process is
similar to the process for selecting OST services when you create a file system (see Section 5.2.3).
5. When you have finished adding OST services to the file system, restart the file system, as shown in the
following example:
sfs> start filesystem data
6. When the file system restarts, the client nodes can remount the file system. If a client node fails to
remount the file system, reboot the client node.
5.6.1.1 Usable space on new OST services
Because of the way the file striping mechanism works, it may not be possible to use all of the space available
on the new OST services. In the typical case where files are striped across all OST services, new files will
be striped across all OST services, including both the OST services originally assigned to the file system and
the new OST services. However, when the OST services originally assigned to the file system are full, an
error occurs; it is not possible to add further data into those files, even if there is still space available on the
new OST services.
A possible workaround for this problem is as follows: after you have added the new OST services to the file
system, but before any new files are created, copy all existing files and then delete the originals. The copies
of the existing files will be spread across all OST services for the file system (including both the OST services
originally assigned to the file system and the new OST services you have added), and new files can be
allocated successfully until all OST services are full.
5.6.2 Changing the preferred server for OST and MDS services
To change the preferred server for an OST or MDS service, perform the following steps:
1. Unmount the file system on all client nodes.
2. Stop the file system as shown in the following example, where the
data
file is system is stopped:
sfs> stop filesystem data
Do not proceed to the next step (running the
modify filesystem
command) until the file system is
stopped; the file system is stopped when all of the file system services are in the
stopped
or
down
state. See Section 3.7 for more information on the
stop filesystem
command.
3. When the file system is stopped, enter the
modify filesystem
command, as shown in the
following example:
sfs> modify filesystem data
Select an option:
1) Add OSTs
2) Change stripe size
3) Change stripe count
4) Change mount point
5) Change preferred servers
6) Change LUN mount options
7) Change interconnect
8) Change Lustre timeout
9) Change quota options
w) Rewrite LDAP configuration data
c) Cancel
Enter your choice [c]:
4. Select the
Change preferred servers
option, as follows:
Enter your choice [c]: 5