HP VMA SAN Gateway for VMA-series Memory Arrays Release Notes - August 2012 - Software OE version G5.1.0

17
Supported web browsers with vSHARE GUI
To launch the vSHARE web-based GUI, enter the VMA SAN Gateway IP address in the web address
space of the web browser. The vSHARE GUI requires the Java plug-in to be added and enabled in
the web browser in order to function correctly. Supported web browsers for use with the vSHARE
web-based GUI are:
• Internet Explorer (IE) version 8 or newer. When using IE, disable IE compatibility mode:
(Tools -> ‘Compatibility View Settings’ ->
uncheck ‘Display Intranet sites in Compatibility View’)
• Mozilla Firefox version 6 or newer
VMA SAN Gateway: general recommendations and
limitations
The following are general recommendations for getting optimal performance with the HP VMA SAN
Gateway and connected HP VMA-series Memory Arrays.
Alignment of data transfer I/O block sizes
The internal flash addressing of the VMA is based on 4K (4096) byte boundaries. Read or write
requests that do not begin on a 4KB aligned target block address or are of I/O sizes not a multiple
of 4KB might suffer a performance impact. Write performance is more seriously affected by non-
4KB alignment. For example, if a user application writes 512 bytes starting at the last 256 bytes of a
4K page, the result on hardware would be two 4K read-modify-write updates.
In order to achieve optimal throughput and performance with the VMA-series Memory Arrays, care
should be given to tuning the intended application, data layout structures on the array, and the
connected host server.
Data layout structure alignment on VMA Array LUNs
The data layout structures created on the VMA LUNs by a logical volume manager and file system
on the host should be made so that they are 4KB aligned, meaning that partition sizes, LVM striping
and other data structures are 4KB aligned. Consider the following when creating data layout
structures on the VMA:
• Partition sizes are 4KB aligned
• Volume manager stripe sizes are multiple of 4KB
• File system blocks are 4KB aligned
ext2 filesystem is not supported
The ext2 filesystem on Linux distros has outstanding known data integrity issues. It is highly
recommended that you use an alternative filesystem such as ext3 or ext4 instead.
Tune application to issue I/Os which are multiple of 4KB
Most high level applications can be configured to issue certain I/O block sizes for increased
performance. Ensure that configured I/O block size and if appropriate the beginning block
addresses for I/Os are 4KB aligned.