Christo,
thnx for your response again.
You wrote me basically that I might want to
lower my mount retention period, because:
"Once a process has completed the tape"
"is retained in the drive for the time "
"set in mount retention period."
"If a process is cancelled it will ignore the mount "
"retention period and dismount"
"the tape immediately and the next process can "
"use the drive."
First I believed this would be correct explanation,
but after few observations I have to contradict:
)) If a process is cancelled, the tape will NOT be
dismounted immediatelly. The tape will be kept
MOUNTed/IDLE for the retention period.
Only if there is lack of free mount points during
this time, then such tape will be dismounted immediatelly.
)) Conclusion:
the treatment of tapes in MOUNTed/IDLE state
is inconsistent :
the behaviour of tapes in MOUNTed/IDLE state
depends on the transition which changed
MOUNTed/IN_USE state to MOUNTed/IDLE state.
So , in fact, there must be at least two different
MOUNTed/IDLE states of tapes, whatever sense it may have.
Let us name this states
A_MOUNTed/IDLE state and
B_MOUNT_ed/IDLE state.
QUERY MOUNT tells, however, no difference between them,
it will always only output:
"ANR8329I ... volume ... MOUNTED ..., status: IDLE"
If {
normal completion of a process changes MOUNTed/IN_USE
state of tape into A_MOUNTed/IDLE state,
and cancel of of a process changes MOUNTed/IN_USE
state of tape into B_MOUNTed/IDLE state,
and there are no free mount points,
}
then following is true:
{
any proceses in WAITING_ON_MOUNT_POINT state
will cause the change of B_MOUNTed/IDLE tape
to DISMOUNTED state an thus get changed itself to
RUNNING state,
}
{
but A_MOUNTed/IDLE tapes will remain stubborn
in their MOUNTed state untill retention
period expires, thus possibly leaving
some precesses in WAITING_ON_MOUNT_POINT.
}
Tip: Paintig few status bubles on a piece of paper
makes all of this much more simple to understand.
While both manners have pro´s and contras,
having two different of them
while neither beeing able to choose between them,
nor beeing able to simply explore
which one is currently active,
makes no sense to me.
And a workaround for me?
1) I could shorten my retention period,
but it raised another problems for my installation.
2) maybe I should raise a requirement ?
IS THERE ANYBODY AMONG YOU WHO WOULD
BE DISTURBED BY FOLLOWING BEHAVIOUR OF ADSM:
As soon as there is at least one proces
WAITING FOR MOUNT POINTS
and not enough free mount points,
but enough tapes in MOUNTed/IDLE state,
such tapes should be DISMOUNTED even during
their retention period so that the WAITING proces
with highest priority (among those waiting)
may become RUNNING ??
This is currently true only if MOUNTed/IDLE tapes
were previously accessed by processes which
were canceled, but it is false if such processes
ended normally. (ADSM/2 v2)
Juraj Salak
KEBA Banking,
Linz,
Austria
sal AT keba.co DOT at
~ Hi Juraj,
~
~ I posted to the list but get a very ugly message saying it was not
sent so I'll
~
~ send it to you directly....
~
~ You must look at your mount retention period in your devclass
definition:
~ The default is 60 minutes.
~ Once a process has completed - in this case your restore process the
tape
~ is retained in the drive for the time set in mount retention period.
~ If a process is cancelled it will ignore the mount retention period
and
~ dismount
~ the tape immediately and the next process can use the drive as you
have
~ seen.
~
~ Hope this helps!
~
~ Regards
~ Christo Heuer
~ Johannesburg
~ South Africa
~ Christoh AT absa.co DOT za
~
~~ Hi!
~~
~~ I recently upgraded to ADSM/2 V2 (CSD Level 21020),
~~ and I believe this version waits occassionally for free tape slot
even if there is one free.
~~ Example:
~~
~~ Configuration: 2 tape drives of one device class DAT in one manual
library. Mountlimit=2.
~~ Storage Pool PCBSDISK has 2 migration processes defined.
~~
~~ At some time, there is one tape PCBS10 mounted, used for RESTORE
Session.
~~
~~ During this, 2 migration processes for PCBSDISK start.
~~
~~ One of them (#8) can mount a tape, the second (#9) has to wait.
~~
~~ Restore ends, leaving tape PCBS10 in IDLE state.
~~
~~ But - migration process #9 still waits for mount point,
~~ tape PCBS10 remains in MOUNT/IDLE state.
~~
~~ DISMOUNTING the tape manually does not help - process #9 still waits.
~~
~~ CANcelling process #8 releases its tape.
~~ Because the disk storage pool PCBSDISK is still candidate for
migration,
~~ a new migration process #10 is started instead. Now, each of both
processes
~~ requires a tape and is able to mount it.
~~
~~
~~ Can someone explain me this behaviour ?
~~
~~ Juraj SALAK
~~ KEBA Banking
~~ Linz, Austria
~~
~~
~~
~~
~~
~~ ADSM > Q SES
~~
~~ Sess Comm. Sess Wait Bytes Bytes
Sess Platform Client Name
~~ Number Method State Time Sent Recvd
Type
~~ ------ ------ ------ ------ ------- -------
----- -------- --------------------
~~ 2 Tcp/Ip Run 0 S 13.5 K 114
~~ 2 Tcp/Ip Run 0 S 13.5 K 114
Admin OS/2 VIEW
~~ 3 Tcp/Ip Run 0 S 9.2 K 114
Admin OS/2 VIEW
~~ 13 Tcp/Ip IdleW 6 S 40.4 M 68.5 M
Node OS/2 BTSDOM
~~ 21 Tcp/Ip Run 0 S 39.3 K 1.5 K
Admin OS/2 SALADSMADMIN
~~
~~
~~ ADSM > Q PROC
~~
~~ Process Process Description Status
~~ Number
~~ -------- --------------------
-------------------------------------------------
~~ 8 Migration Disk Storage Pool PCBSDISK,
~~ 8 Migration Disk Storage Pool PCBSDISK,
Moved Files: 1235,
~~ Moved Bytes: 167,673,856,
Unreadable Files: 0,
~~ Unreadable Bytes: 0. Current
File (bytes):
~~ 1,200,128
~~
~~ Current output volume: PCBS35.
~~
~~ 9 Migration Disk Storage Pool PCBSDISK,
Moved Files: 0, Moved
~~ Bytes: 0, Unreadable Files: 0,
Unreadable Bytes:
~~ 0. Current File (bytes): 4,096
~~
~~ Waiting for mount point in
device class DAT
~~ (6237 seconds).
~~
~~ ADSM > Q MOUNT
~~
~~ ANR8330I DAT volume PCBS35 is mounted R/W in drive TAPE2 (TAPE05$),
status: IN USE.
~~ ANR8330I DAT volume PCBS10 is mounted R/W in drive TAPE1 (TAPE06$),
status: IDLE.
~~ ANR8334I 1 volumes found.
~~
~~ ADSM > Q DEVC DAT
~~
~~ Device Device Storage Device Format
Est/Max Mount
~~ Class Access Pool Type
Capacity Limit
~~ Name Strategy Count
(MB)
~~ --------- ---------- ------- --------- ------
-------- -----
~~ DAT Sequential 5 4MM DDS2C
~~ DAT Sequential 5 4MM DDS2C
0.0 2
~~
~~
~~ ADSM > DISMOUNT vol PCBS10
~~
~~ *** after minutes, process 9 still waiting for mount point***
~~
~~ ADSM > CANCEL PROC 8
~~
~~ ADSM > Q PROC PROC
~~
~~
~~
~~
~~ 9 Migration Disk Storage Pool PCBSDISK,
Moved Files: 0, Moved
~~ Bytes: 0, Unreadable Files: 0,
Unreadable Bytes:
~~ 0. Current File (bytes): 4,096
~~
~~ Waiting for mount of output
volume PCBS23 (168
~~ seconds).
~~
~~ 10 Migration Disk Storage Pool PCBSDISK,
Moved Files: 0, Moved
~~ Bytes: 0, Unreadable Files: 0,
Unreadable Bytes:
~~ 0. Current File (bytes):
110,592
~~
~~ Waiting for mount of output
volume PCBS22 (132
~~ seconds).
~~
~~
~~ ** here I can load tapes an both migration processes can run. ***
|
