[dm-devel] Swapping on device-mapper targets

[public0x05bf at bluewin.ch]

>From Thomas Bruecker, Switzerland. 


Dear DM-Developers,

I have questions about swapping to device-mapper targets:

Question 1:

Provided that "sda1" and "sdb1" are two devices, to which I may swap without
any problems, e.g. with the entries in "/etc/fstab":

"
/dev/sda1   swap    swap    defaults     0 0
/dev/sdb1   swap    swap    defaults     0 0
".

May I swap also to the mirror target "test_raid" created by the statement

' dmsetup  create test_raid \
    --table "0 8388608   mirror   core 2 8388608 sync \
             2  /dev/sda1 0  /dev/sdb1 0 " '

without any problems (e.g. deadlocks)? (The command above completes
successfully and therefore there is enough space on "sda1" and "sdb1" to create
the target.)


Question 2:

Provided the table entry form for a mirror target is:

' ... --table " $START $LENGTH mirror \
                $LOG_TYPE $NumLOGARGS $LOGARG1 ... $LOGARGm \
                $NumDEVS  $DEVICE1 $OFFSET1 ... $DEVICEn $OFFSETn "
'
Does your answer to question 1 only hold for the parameters I specified in
question 1 or for all legal parameters $... (of the above table entry form)?

I have searched your site "http://www.redhat.com/archives/dm-devel/" by google
for answers to my above questions, but I have not found any answer to them
there. So I would be happy to get an answer from you.

Sincerely

Thomas Bruecker