Installation Manual

HP StorageWorks File System Extender Software installation guide for Linux 17
Sample calculation for the expected sizes of HSM file system, FSC and HSMDB
The following is an example of a calculation of space required on an HSM file system and on the file
systems holding File System Catalog (FSC), and HSM Database (HSMDB), and Fast Recovery Information
(FRI) files.
Sample input for calculations:
• HSM file system can store 10 million entities (files and directories)
• average size of files being migrated is 100 KB
• 20% of the files are online
(online means they occupy space on the local HSM file system)
• 20% of all entities on the HSM file system are directories
• the average file name length of files being migrated is 10 characters
• files have only one generation
• average number of copies per file generation amounts to two
HSM file system size calculation:
FSC size calculation:
HSMDB size calculation:
Sample results:
• minimum HSM file system size: 216-306 GB, depending on the block size (1 KB, 2 KB, 4 KB)
• maximum File System Catalog size: 453 MB
• maximum HSM Database size: 287 MB
The File System Catalog and the HSMDB together require 740 MB. That is approximately 0.3% of the size
of minimum required HSM file system size for this input.
Sample calculation for the expected total size of the FRI files
The following is an example of a calculation of space required on the file system holding the Fast Recovery
Information (FRI) files.
Sample input for calculation:
• total number of open FSE medium volumes in the FSE implementation is 8
• size of an FSE medium volume on tape is 5135 MB
• average size of files being migrated is 100 KB
• average file name length of files being migrated is 10 characters
• average number of files migrated together in the same migration job is 50
• block size on tape medium is 128 KB
Sample result:
• estimated maximum size of FRI files on disk: 1027 MB
Space requirements of FSE disk buffer
To determine the approximate storage space required by FSE disk buffer, you should consider the following
points:
First generation takes (162 for FSC) + (36 for volume index) = 198 bytes
There are no additional generations
Total FSC size = ((198 + add. attr. size) x 10000000) + (56 x 0)
minHSMFSsize
125 afs nf× pon×()bks 2× nf×()+[]×
100
--------- ------------------------------ -------------------------------------- ---------------------=
maxHSMDBSize 10000000 12×()10000000 20× 10 30+()×[]10000000 20× 10 40+()×[]++=