[DRBD-user] "kernel: bio too big device drbd0"

Sebastian Riemer sebastian.riemer at profitbricks.com
Mon Jun 10 14:17:36 CEST 2013

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

On 10.06.2013 13:46, Lutz Vieweg wrote:
>> I wonder why the peer has smaller max bio size in the first place,
>> though.
> Because the harddisk in the peer is connected to a 3ware/LSI 9750
> controller
> which supports a max_hw_sectors_kb size of 128, only - while the harddisk
> in the primary is connected to an on-board controller supporting much
> larger
> values.
> (BTW: The 3ware/LSI raid controllers perform incredibly bad when used with
> fast SSDs due to this ridiculously low max_hw_sectors_kb - it seems they
> try
> to promote their overpriced "SSD support" add-on-dongle that way. I can
> only
> say that I'll never buy a 3ware/LSI controller again, because of that.)

Btw: You can change that on LSI MegaRAID controllers. My dear friends
from Thomas-Krenn.AG have written it into their wiki:


(Sorry, the explanation is German but the rest is in English. You're
from Germany anyway.). They are translating their wiki gradually into

The driver megaraid_sas has a module parameter "max_sectors".


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