Issuing A Mount Job From The Host - Fujitsu Siemens Computers pmn User Manual

CentricStor - Virtual Tape Library

2.6.2 Issuing a mount job from the host

Initial situation:
Figure 14: Procedure for a mount job
A mount job is executed as follows:
1. The host issues a mount job for logical volume LV0005, which is then accepted by the
VLM.
The VLM does not know at this point what task is involved:
–
–
–
2. The VLM checks its data maintenance to establish whether the logical volume LV0005
specified by the host is available and whether there is a corresponding free storage
space on the RAID system.
If the RAID system does not have enough free capacity at this point, the LRU (Least
Recently Used) procedure is employed to delete the oldest data from the RAID system.
If a sufficient number of old files cannot be deleted, the mount job is suspended ("Mount
queued").
U41117-J-Z125-7-76
The logical volume LV0005 is already located on the physical volume
PV0002.
2
LV0000
LV0001 M
LV0002
LV0003
Host
LV0004
LV0005
LV0006 M
LV0007
LV0008
LV0009 M
LV0010 D
LV0011
LV0005
3
1
Data
4
read the volume or a part thereof
append a file to the end of the volume
overwrite the entire volume
CentricStor
a
VLM PLM
f
PV0000
LV0000
LV0001
LV0003
5
PV0001
e
LV0004
LV0017
PV0002
LV0027
LV0005
LV0013
PV0004
RAID
Logical volumes
LV0005
d
Data
b
Robots
c
PV0002
LV0027 LV0005 LV0013
Physical volumes
PV0012
PV0009
PV0006
PV0003
PV0000
LV0000 LV0001
PV0000
PV0000
PV0007
PV0004
PV0001
LV0004
PV0000
PV0000
PV0008
PV0005
PV0002
LV0061 LV0073
Procedures
Tape drive
LV0003
LV0017
39