Am 22.11.2012 15:52, schrieb Alexandre DERUMIER:
I discussed this with somebody frmo inktank. Had to search the
mailinglist. It might be OK if you're working with enough replicas and UPS.
I see no other option while working with SSDs - the only Option would be
to be able to deaktivate the journal at all. But ceph does not support this.
Do you have a big difference with putting 1 journal by osd on each ssd drive ?
Not tested.
another alternative can be (but indeed costly):
- stec zeus ram ssd drive, around 2000$ for 8G (I have benched it around 100000 iops ;)
- ddrdrive (http://www.ddrdrive.com/) (around 200000iops, don't know the price)
- fusionio card (iodrive2, 360GB, around 3000€ , but they are 160GB model, maybe half the price)
All too expensive.
- maybe ocz talos, around 600€ for OCZ Talos 2 R 200 Go (don't have benched them, but spec say around 35000iops random)
Not usable as each OSD can do 35.000 random IOP/s in my case and have 8
of them in each node...
Stefan
----- Mail original -----
De: "Stefan Priebe - Profihost AG" <s.priebe@xxxxxxxxxxxx>
À: "Mark Nelson" <mark.nelson@xxxxxxxxxxx>
Cc: "Alexandre DERUMIER" <aderumier@xxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>, "Mark Kampe" <mark.kampe@xxxxxxxxxxx>, "Sébastien Han" <han.sebastien@xxxxxxxxx>
Envoyé: Jeudi 22 Novembre 2012 15:42:14
Objet: Re: RBD fio Performance concerns
Am 22.11.2012 15:37, schrieb Mark Nelson:
I don't think we recommend tmpfs at all for anything other than playing
around. :)
I discussed this with somebody frmo inktank. Had to search the
mailinglist. It might be OK if you're working with enough replicas and UPS.
I see no other option while working with SSDs - the only Option would be
to be able to deaktivate the journal at all. But ceph does not support this.
Stefan
On 11/22/2012 08:22 AM, Stefan Priebe - Profihost AG wrote:
Hi,
can someone from inktank comment this? Might be using /dev/ram0 with an
fs on it be better than tmpfs as we can use dio?
Greets,
Stefan
----- Mail original -----
De: "Stefan Priebe - Profihost AG" <s.priebe@xxxxxxxxxxxx>
À: "Sébastien Han" <han.sebastien@xxxxxxxxx>
Cc: "Mark Nelson" <mark.nelson@xxxxxxxxxxx>, "Alexandre DERUMIER"
<aderumier@xxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx>,
"Mark Kampe" <mark.kampe@xxxxxxxxxxx>
Envoyé: Jeudi 22 Novembre 2012 14:29:03
Objet: Re: RBD fio Performance concerns
Am 22.11.2012 14:22, schrieb Sébastien Han:
And RAMDISK devices are too expensive.
It would make sense in your infra, but yes they are really expensive.
We need something like tmpfs - running in local memory but support dio.
Stefan
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