We have a customer that uses DRBD extensively for replicating ~100 GB between x 80 VM pairs. They run in ESXi 6.5 VMFS 6.0 with thick provisioned disk. DRBD 8.9.6 runs on top of LVM.
Our task is to reduce the storage footprint of their VMs thus we need to implement discard to reclaim the disk space released by deleted files in ext3/4 that sits on top of DRBD.
Both the /dev/sd* and /dev/vg/lv* support discard but DRBD does not so we cannot
# fstrim -v /mnt
because "fstrim: /mnt: the discard operation is not supported"
I have read here http://docs.linbit.com/doc/users-guide-84/re-drbdconf/
but is unclear if there is a combination of parameters to change this behavior "While probably harmless for most use cases (fstrim on a file system), DRBD cannot have that."
I have tried a few parameters but failed.
Can you please let me know what is the combination of parameters to instruct DRBD to allow fstim?
The platform is SLES 12SP2 and kernel 4.4.27-2.
Best regards,
-------------------------------- Friday, March 31, 2017----- 1:59 AM GMT+2
Sergiu Pol
Infrastructure Architect
Email: [email protected]
GSM: 0040742962266
www.simplision.com
-----------------------------------------------------------------------------------
_______________________________________________ drbd-user mailing list [email protected] http://lists.linbit.com/mailman/listinfo/drbd-user
