Installation Manual

HP StorageWorks File System Extender Software installation guide for Linux 15
IMPORTANT: FSE includes the utility HSM Health Monitor, which helps preventing file systems for FSE
databases and system files and HSM file systems from running out of free space. For details, see the FSE
user guide, chapter ”Monitoring and maintaining FSE”, section ”Low storage space detection”.
Formula for the expected HSM file system size
Use this simplified formula to calculate the minimum HSM file system size:
The parameters have the following meaning:
Formula for the expected size of Fast Recovery Information
Fast Recovery Information (FRI) consists of a set of files, each corresponding to a single open data volume
on a configured FSE medium, which grows in size as the percentage of used space on the volume
increases. FRI files reach maximum size when the corresponding data volume becomes full. The FRI files
are then copied to appropriate locations on the FSE medium and removed from disk.
Use this formula to calculate the expected maximum size of FRI files on disk:
where the meaning of the parameters is:
Formula for the expected File System Catalog size
The File System Catalog (FSC) is a database that consists of the Data Location Catalog (DLC) and the
Name Space Catalog (NSC). The DLC records the full history of file locations on FSE media. The NSC
contains metadata of files on an HSM file system.
Factors used for FSC size estimation:
• Approximate usage 180 bytes per file for FSC (DLC + NSC) for typical file generation with two copies
and file name size of 16 characters using standard file attributes (Linux). You need to add the size of
additional attributes on Windows - access control lists (ACLs), extended attributes (EAs) and alternate
data streams (ADSs).
• Additional 36 bytes for media volume index for each file copy is required when you run FSC
consistency check. This will be used on the first run of consistency check.
minHSMFSsize ..... the minimum required HSM file-system size in bytes.
afs ..... the average file size in bytes.
nf ..... the expected number of files on an HSM file system.
pon ..... the percentage of online files (%).
bks ..... the file-system block size in bytes.
minHSMFSsize
125 afs nf× pon×()bks 2× nf×()+[]×
100
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maxFRIsize ..... the estimated maximum size of FRI files on disk in bytes.
nv ..... the total number of open FSE medium volumes
1
in the FSE implementation.
1. Normally, the number of configured FSE media pools containing media with migrated files.
sv ..... the size of an FSE medium volume on tape in bytes.
lf ..... the average file name length of files being migrated in bytes.
nm ..... the average number of files migrated together in the same migration job.
tbks ..... the block size on an FSE medium
2
in bytes.
2. Assuming all FSE media pools are configured with the same block size (block size is uniform on all FSE media).
sf ..... the average size of files being migrated in bytes.
[...] ..... square brackets indicate that the value inside is rounded up to an integer.
maxFRIsize
nv sv lf 350+()nm tbks⁄×[]××
sf nm tbks⁄×[]
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