Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Florian, I've watched your video, very interesting indeed... Unfortunately for you it raised some more questions to me :-) First, just to be sure I correctly understood : flashcache will only (But significantly) improve read operations, no impact or so on writes right ? Then, a year or 2 ago I had the opportunity to play around with Ming Zhao's dm-cache (completely apart from DRBD by the way, it was a standalone system), and to what I remember it roughly looked like this flashcache thing I didn't know of, except it makes use of a ramdisk instead of an SSD drive (And it has an impact on write operations, as far as I remember). I immediately see one advantage compared to flash-cache : it would (should?) be more performant, being memory-based instead of IO-based. However, inconvenient, it would be certainly smaller. Have you ever had the chance to add that dm-cache feature to DRBD the way you did it with flashcache ? Do you know/think it would work efficiently with DRBD ? And, lastly, do you think it would make sense to think of combining dm-cache and flashcache together to get kind of an L1+L2 storage cache level pair ? Best regards, Pascal. -----Message d'origine----- De : drbd-user-bounces at lists.linbit.com [mailto:drbd-user-bounces at lists.linbit.com] De la part de Florian Haas Envoyé : vendredi 10 février 2012 20:50 À : drbd-user at lists.linbit.com Objet : Re: [DRBD-user] drbd + flashcache On Fri, Feb 10, 2012 at 3:38 PM, Maurits van de Lande <M.vandeLande at vdl-fittings.com> wrote: > Hello, > > I'm exploring the features of flashcache see: http://www.github.com/facebook/flashcache and I like it's possibilities. > Fortunately toracat from elrepo has been so kind to create an el6 package. http://elrepo.org/bugs/view.php?id=228 > > I'm thinking of using flashcache with drbd in the following setup: > > - Centos6.2 (currently) > - /dev/sdc : a RAID1 SSD array as flashcache > - /dev/sdb : a RAID5 HD array for storage > > Then to create a cached storage array (cached sdb using sdc) > /dev/mapper/flashcache1 > > I would like to use that device for drbd. Can this cached storage array be used as a drbd target? I've recently done a talk that explores this in detail: http://youtu.be/l910kiEuHOM Hope this is useful. Cheers, Florian -- Need help with High Availability? http://www.hastexo.com/now _______________________________________________ drbd-user mailing list drbd-user at lists.linbit.com http://lists.linbit.com/mailman/listinfo/drbd-user