Ok, now I do see sync writes to the LUN over iscsi from MS initiator - when I 
disable write-back cache. The strange thing is sync on nfs - it's always there.

Disabling write-back on iscsi decreases speed by 50 times to 1.5MB/s on a full 
format operation.

My concern now is applications data (MS Exchange in particular).
Am I understand correctly that write-back cache on lun can lead to data 
corruption if a storage server fails and if it works without non-volatile 
memory?

An application gets confirmation that data has been written, but it's only in 
zfs tpg, right? Data remains consistent on disk, but from application point of 
view data order will be lost.

What are rhe solutions?
Except SSD which also can lead to pool damage (because of the bug - slog can't 
be removed).
NVRAM?

--
Roman
-- 
This message posted from opensolaris.org
_______________________________________________
storage-discuss mailing list
[email protected]
http://mail.opensolaris.org/mailman/listinfo/storage-discuss

Reply via email to