[zfs-discuss] controller cache instead of dedicated ZIL device

2010-02-23 Thread Felix Buenemann
t ZIL accelerator, requiring no dedicated ZIL? If my understanding is correct, a battery backed RAID controller will ignore cache flush commands and thus the controller cache would be a very low latency intermediate cache wich is preserved over power failure. Best Regards, Felix Buen

Re: [zfs-discuss] l2arc current usage (population size)

2010-02-21 Thread Felix Buenemann
Am 20.02.10 03:22, schrieb Tomas Ögren: On 19 February, 2010 - Christo Kutrovsky sent me these 0,5K bytes: How do you tell how much of your l2arc is populated? I've been looking for a while now, can't seem to find it. Must be easy, as this blog entry shows it over time: http://blogs.sun.com/b

Re: [zfs-discuss] Poor ZIL SLC SSD performance

2010-02-19 Thread Felix Buenemann
Am 20.02.10 01:33, schrieb Toby Thain: On 19-Feb-10, at 5:40 PM, Eugen Leitl wrote: On Fri, Feb 19, 2010 at 11:17:29PM +0100, Felix Buenemann wrote: I found the Hyperdrive 5/5M, which is a half-height drive bay sata ramdisk with battery backup and auto-backup to compact flash at power

Re: [zfs-discuss] Poor ZIL SLC SSD performance

2010-02-19 Thread Felix Buenemann
Am 19.02.10 21:29, schrieb Marion Hakanson: felix.buenem...@googlemail.com said: I think I'll try one of thise inexpensive battery-backed PCI RAM drives from Gigabyte and see how much IOPS they can pull. Another poster, Tracy Bernath, got decent ZIL IOPS from an OCZ Vertex unit. Dunno if that

Re: [zfs-discuss] Poor ZIL SLC SSD performance

2010-02-19 Thread Felix Buenemann
Am 19.02.10 20:50, schrieb Bob Friesenhahn: On Fri, 19 Feb 2010, David Dyer-Bennet wrote: Too bad, I'm getting ~1000 IOPS with an Intel X25-M G2 MLC and around 300 with a regular USB stick, so 50 IOPS is really poor for an SLC SSD. Well, but the Intel X25-M is the drive that really first crac

Re: [zfs-discuss] Poor ZIL SLC SSD performance

2010-02-19 Thread Felix Buenemann
Am 19.02.10 19:30, schrieb Bob Friesenhahn: On Fri, 19 Feb 2010, Felix Buenemann wrote: So it is apparent, that the SSD has really poor random writes. But I was under the impression, that the ZIL is mostly sequential writes or was I misinformed here? Maybe the cache syncs bring the device to

[zfs-discuss] Poor ZIL SLC SSD performance

2010-02-19 Thread Felix Buenemann
e? Maybe the cache syncs bring the device to it's knees? Best Regards, Felix Buenemann ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

Re: [zfs-discuss] ZFS ZIL + L2ARC SSD Setup

2010-02-12 Thread Felix Buenemann
Am 12.02.10 18:17, schrieb Richard Elling: On Feb 12, 2010, at 8:20 AM, Felix Buenemann wrote: Hi Mickaël, Am 12.02.10 13:49, schrieb Mickaël Maillot: Intel X-25 M are MLC not SLC, there are very good for L2ARC. Yes, I'm only using those for L2ARC, I'm planing on getting to Mtro

Re: [zfs-discuss] ZFS ZIL + L2ARC SSD Setup

2010-02-12 Thread Felix Buenemann
b of L2ARC with only 4Gb of RAM because ZFS use memory to allocate and manage L2ARC. Is there a guideline in which relation L2ARC size should be to RAM? I could upgrade the server to 8GB, but that's the maximum the i975X chipset can handle. Best Regards,

Re: [zfs-discuss] ZFS ZIL + L2ARC SSD Setup

2010-02-09 Thread Felix Buenemann
Am 09.02.10 09:58, schrieb Felix Buenemann: Am 09.02.10 02:30, schrieb Bob Friesenhahn: On Tue, 9 Feb 2010, Felix Buenemann wrote: Well to make things short: Using JBOD + ZFS Striped Mirrors vs. controller's RAID10, dropped the max. sequential read I/O from over 400 MByte/s to below 300

Re: [zfs-discuss] ZFS ZIL + L2ARC SSD Setup

2010-02-09 Thread Felix Buenemann
Am 09.02.10 02:30, schrieb Bob Friesenhahn: On Tue, 9 Feb 2010, Felix Buenemann wrote: Well to make things short: Using JBOD + ZFS Striped Mirrors vs. controller's RAID10, dropped the max. sequential read I/O from over 400 MByte/s to below 300 MByte/s. However random I/O and sequential w

Re: [zfs-discuss] ZFS ZIL + L2ARC SSD Setup

2010-02-08 Thread Felix Buenemann
Am 08.02.10 22:23, schrieb Bob Friesenhahn: On Mon, 8 Feb 2010, Richard Elling wrote: If there is insufficient controller bandwidth capacity, then the controller becomes the bottleneck. We don't tend to see this for HDDs, but SSDs can crush a controller and channel. It is definitely seen w

Re: [zfs-discuss] ZFS ZIL + L2ARC SSD Setup

2010-02-08 Thread Felix Buenemann
Hi Daniel, Am 08.02.10 05:45, schrieb Daniel Carosone: On Mon, Feb 08, 2010 at 04:58:38AM +0100, Felix Buenemann wrote: I have some questions about the choice of SSDs to use for ZIL and L2ARC. I have one answer. The other questions are mostly related to your raid controller, which I can&#

[zfs-discuss] ZFS ZIL + L2ARC SSD Setup

2010-02-07 Thread Felix Buenemann
use HW RAID10 on the storage controller or would I get better performance out of JBOD + ZFS RAIDZ2? Best Regards, Felix Buenemann ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss