HP D2D D2D NAS Integration with NetBackup (EH985-90936, March 2011) - Page 32

A Open file limits and recommended streams per NAS share for D2D Backup Systems - d2d2504i backup system

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A Open file limits and recommended streams per NAS share for D2D Backup Systems Table 1 Open file limits and recommended streams per share HP D2D2502i HP D2D2504i HP D2D4106 Max files per share 25000 25000 25000 Max Open files per 32 48 64 share > 24 MB (DD threshold) Max Open files per 32 48 64 appliance > 24 MB (DD threshold) Max Total Open files 96 per share 112 128 Suggested maximum 4 4 6 concurrent operations per share Suggested maximum 16 32 48 concurrent operations per appliance HP D2D4112 HP D2D4312 HP D2D4324 25000 25000 25000 64 128 128 64 128 128 128 640 640 6 12 12 48 64 64 The HP D2D NAS target for backup does not deduplicate the first 24 MB of any file for performance reasons. Some backup applications generate control files during backup to NAS that are constantly changing - to try and deduplicate constantly changing files slows down the deduplication process. For any single D2D NAS share there are specific limits as to how many "Open Files" can be open at any one time - this is because of the memory allocation within the D2D Backup System. Generally, typical Filesystem backups like NetBackup will open a single large container one at a time, but it is possible due to overlapping operations that two may be open at the same time for a small period of time. It is important NOT to send too many backup jobs to the same NAS share to avoid exceeding the NAS > 24MB open file limit per share and per appliance. (Appliance is the whole D2D Backup System). Failure to observe these limits can result in unstable operation. For example: An HP D2D4312 has 4 shares configured on it. We are running filesystem backups which open up a single container file at a time. The maximum number of backup jobs that can go to each share is 12 so we can have a total of 48 backup jobs running simultaneously and, even allowing for 2 files overlapping and being monitored as open at the same time, we would have a maximum of 96 files open on the appliance in a worst case scenario. This is well within the appliance limit of 128 open files. 32 Open file limits and recommended streams per NAS share for D2D Backup Systems

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A Open file limits and recommended streams per NAS share
for D2D Backup Systems
Table 1 Open file limits and recommended streams per share
HP D2D4324
HP D2D4312
HP D2D4112
HP D2D4106
HP D2D2504i
HP D2D2502i
25000
25000
25000
25000
25000
25000
Max files per share
128
128
64
64
48
32
Max Open files per
share > 24 MB (DD
threshold)
128
128
64
64
48
32
Max Open files per
appliance > 24 MB
(DD threshold)
640
640
128
128
112
96
Max Total Open files
per share
12
12
6
6
4
4
Suggested maximum
concurrent operations
per share
64
64
48
48
32
16
Suggested maximum
concurrent operations
per appliance
The HP D2D NAS target for backup does not deduplicate the first 24 MB of any file for performance
reasons. Some backup applications generate control files during backup to NAS that are constantly
changing – to try and deduplicate constantly changing files slows down the deduplication process.
For any single D2D NAS share there are specific limits as to how many “Open Files” can be open
at any one time – this is because of the memory allocation within the D2D Backup System. Generally,
typical Filesystem backups like NetBackup will open a single large container one at a time, but it
is possible due to overlapping operations that two may be open at the same time for a small period
of time. It is important NOT to send too many backup jobs to the same NAS share to avoid
exceeding the NAS > 24MB open file limit per share and per appliance. (Appliance is the whole
D2D Backup System). Failure to observe these limits can result in unstable operation.
For example: An HP D2D4312 has 4 shares configured on it. We are running filesystem backups
which open up a single container file at a time. The maximum number of backup jobs that can go
to each share is 12 so we can have a total of 48 backup jobs running simultaneously and, even
allowing for 2 files overlapping and being monitored as open at the same time, we would have
a maximum of 96 files open on the appliance in a worst case scenario. This is well within the
appliance limit of 128 open files.
32
Open file limits and recommended streams per NAS share for D2D Backup Systems