AW: [DRBD-user] Behaviour of drbd-secondary

Seuberth, Frank F.Seuberth at
Wed Mar 23 12:41:45 CET 2005

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


just for thinking aubout technik :
Immagine that the secondary has a Software RAID 1 under the drbd.
take out (hotremove) the (raid1-) mirror, mount, do_what_you_want,
unmount, raid-hot-add it again to the raid1.

possible ?


-----Ursprüngliche Nachricht-----
Von: drbd-user-bounces at
[mailto:drbd-user-bounces at]Im Auftrag von Philipp
Gesendet: Mittwoch, 23. März 2005 12:19
An: Filip Sergeys
Cc: drbd-user at
Betreff: Re: [DRBD-user] Behaviour of drbd-secondary

>     My experiences are:
>      - ext2/ext3 will print some assertions to the kernel log, return an
> error to the application that wanted to read the file and continue to run.
>      - reiserfs  will crash the machine.
> That means I have been a lucky bastard the last few months. I use
> reiserfs ....  hmmm, I better a solution quick !
> Would a better way be to drbdsetup /dev/nb0 disconnect before mounting
> read only, do my stuff, unmount, and then run drbdsetup /dev/nb0 net xyz
> to bring it in secondary state again?

Well, as you have noticed that the window for this race condition is rather
small -> The probability to hit it is small. __But_it_is_there__ .
Therefore people should not mount a normal filesystem on the secondary.

 Use DRBD-0.7 and mirror the partition that holds the data-base immage
 as well.

: Dipl-Ing Philipp Reisner                      Tel +43-1-8178292-50 :
: LINBIT Information Technologies GmbH          Fax +43-1-8178292-82 :
: Schönbrunnerstr 244, 1120 Vienna, Austria :
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