[DRBD-user] using SSD drives, the TRIM challenge

Kushnir, Michael (NIH/NLM/LHC) [C] michael.kushnir at nih.gov
Fri Mar 9 20:35:23 CET 2012

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


We are replicating a 3.8TB RAID0 with protocol C. We are using LSI 9260-8i RAID cards with SSD protection features and Crucial M4 512GB drives. The array supports OCFS2 v1.4  file system for use by three web servers. Our writes are large but infrequent-- once a month. The array is a year old and we've seen no degradation in performance or stability. See it at work at http://openi.nlm.nih.gov. :)

Michael Kushnir
Lead Unix and VMware Engineer
Communications Engineering Branch
Lister Hill National Center for Biomedical Communications
National Library of Medicine

-----Original Message-----
From: Christoph Roethlisberger [mailto:christoph at iway.ch] 
Sent: Thursday, March 08, 2012 6:10 AM
To: drbd-user at lists.linbit.com
Subject: Re: [DRBD-user] using SSD drives, the TRIM challenge

We are using consumer grade SSD drives in a few of our servers for 4+ years now. (started with MTRON devices, switched to Intel later on and lately also some Samsung drives) Though we just started using SSD drives as DRBD backend storage (hardware
RAID6 - thus no TRIM anyways) we use similar configurations in storage arrays for high IO performance virtual machines. (ESX mostly) So far we had zero problems with it and no measurable performance degradation and only one drive from the 100+ we have, failed so far. Though this happened already after one of two weeks in operation and was an electronic problem and not due to NAND wear out.

As long as the drives have some internal GarbageCollection (as most do
nowadays) and you make sure that they do never fill up completeley (normally we format such arrays to a max of 90% of available space) the absence of TRIM can be neglected in my opinion.

As far as TRIM support in DRBD goes - I don't know.
LVM may support it already in RAID0/1 setups, but MDRaid nor any hardware RAID does it, (and hardware raid support may never ever come/work beside
raid0/1 setups) so this limits the use of TRIM support in DRBD quite much.


Christoph



> Hi all,
>
> I was wondering if anyone is successfully SSD drives as their backend 
> storage devices. If so, I'm wondering if these drives do no degrade 
> quite fast seen there is no TRIM support in DRBD.
>
> I'm also wondering if can motivate people to help sponsor this 
> feature. If the group is large enough, I suppose we can get this done 
> for not too much money.

_______________________________________________
drbd-user mailing list
drbd-user at lists.linbit.com
http://lists.linbit.com/mailman/listinfo/drbd-user



More information about the drbd-user mailing list