similar to: slog/L2ARC on a hard drive and not SSD?

I have three zpools on a server and want to add a mirrored pair of ssd''s for the ZIL. Can the same pair of SSDs be used for the ZIL of all three zpools or is it one ZIL SLOG device per zpool? -- This message posted from opensolaris.org

Hi, I don''t know if it''s already been discussed here, but while thinking about using the OCZ Vertex 2 Pro SSD (which according to spec page has supercaps built in) as a shared slog and L2ARC device it stroke me that this might not be a such a good idea. Because this SSD is MLC based, write cycles are an issue here, though I can''t find any number in their spec. Why do I

Are there any drawbacks to partition a SSD in two parts and use L2ARC on one partition, and ZIL on the other? Any thoughts? -- This message posted from opensolaris.org

Hi, When deploying ZFS in cluster environment it would be nice to be able to have some SSDs as local drives (not on SAN) and when pool switches over to the other node zfs would pick up the node''s local disk drives as L2ARC. To better clarify what I mean lets assume there is a 2-node cluster with 1sx 2540 disk array. Now lets put 4x SSDs in each node (as internal/local drives). Now

Hi, I''ve ordered a new server with: - 4x600GB Toshiba 10K SAS2 Disks - 2x100GB OCZ DENEVA 2R SYNC eMLC SATA (no expander so I hope no SAS/ SATA problems). Specs: http://www.oczenterprise.com/ssd-products/deneva-2-r-sata-6g-2.5-emlc.html I want to use the 2 OCZ SSDs as mirrored intent log devices, but as the intent log needs quite a small amount of the disks (10GB?), I was wondering

I have a pool with a single SLOG device rated at Y iops. If I add a second (non-mirrored) SLOG device also rated at Y iops will my zpool now theoretically be able to handle 2Y iops? Or close to that? Thanks, Ray

What would the performance impact be of splitting up a 64 GB SSD into four partitions of 16 GB each versus having the entire SSD dedicated to each pool? Scenario A: 2 TB Mirror w/ 16 GB read cache partition 2 TB Mirror w/ 16 GB read cache partition 2 TB Mirror w/ 16 GB read cache partition 2 TB Mirror w/ 16 GB read cache partition versus Scenario B: 2 TB Mirror w/ 64 GB read cache SSD 2 TB

I have some questions about the choice of SSDs to use for ZIL and L2ARC. I''m trying to build an OpenSolaris iSCSI SAN out of a whitebox system, which is intended to be used as a backup SAN during storage migration, so it''s built on a tight budget. The system currently has 4GB RAM, 3GHz Core2-Quad and 8x 500GB WD REII SATA HDDs attached to an Areca 8port ARC-1220 controller

Hi all I ran a workload that reads & writes within 10 files each file is 256M, ie, (10 * 256M = 2.5GB total Dataset Size). I have set the ARC max size to 1 GB on etc/system file In the worse case, let us assume that the whole dataset is hot, meaning my workingset size= 2.5GB My SSD flash size = 8GB and being used for L2ARC No slog is used in the pool My File system record size = 8K ,

Hi, as Richard Elling wrote earlier: "For more background, low-cost SSDs intended for the boot market are perfect candidates. Take a X-25V @ 40GB and use 15-20 GB for root and the rest for an L2ARC. For small form factor machines or machines with max capacity of 8GB of RAM (a typical home system) this can make a pleasant improvement over a HDD-only implementation." For the upcoming

Hey folks, This might be a daft idea, but is there any way to shut down solaris / zfs without flushing the slog device? The reason I ask is that we''re planning to use mirrored nvram slogs, and in the long term hope to use a pair of 80GB ioDrives. I''d like to have a large amount of that reserved for write cache (potentially 20-30GB), to facilitate rapid suspend to disk of

I have an Intel X25-M 80GB SSD. For optimum performance, I need to block align the SSD device, but I am not sure exactly how I should to it. If I run the format -> fdisk it allows me to partition based on a cylinder, but I don''t think that is sufficient enough. Can someone tell me how they block aligned an SSD device for use in l2arc. Thanks, Geoff

Hi folks, I would appreciate it if someone can help me understand some weird results I''m seeing with trying to do performance testing with an SSD offloaded ZIL. I''m attempting to improve my infrastructure''s burstable write capacity (ZFS based WebDav servers), and naturally I''m looking at implementing SSD based ZIL devices. I have a test machine with the

apt-get update apt-clone upgrade Any first impressions? -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE

Hello, Im about to migrate a 6Tb database from Veritas Volume Manager to ZFS, I want to set arc_max parameter so ZFS cant use all my system''s memory, but i dont know how much i should set, do you think 24Gb will be enough for a 6Tb database? obviously the more the better but i cant set too much memory. Have someone implemented succesfully something similar? We ran some test and the

We are looking into the possibility of adding a dedicated ZIL and/or L2ARC devices to our pool. We are looking into getting 4 ? 32GB Intel X25-E SSD drives. Would this be a good solution to slow write speeds? We are currently sharing out different slices of the pool to windows servers using comstar and fibrechannel. We are currently getting around 300MB/sec performance with 70-100% disk busy.

Hello all... I''m seeing this behaviour in an old build (89), and i just want to hear from you if there is some known bug about it. I''m aware of the "picket fencing" problem, and that ZFS is not choosing right if write to slog is better or not (thinking if we have a better throughput from disks). But i did not find anything about 100% slog activity (~115MB/s) blocks

This past weekend, but holiday was ruined due to a log device "replacement" gone awry. I posted all about it here: http://jmlittle.blogspot.com/2008/05/problem-with-slogs-how-i-lost.html In a nutshell, an resilver of a single log device with itself, due to the fact one can''t remove a log device from a pool once defined, cause ZFS to fully resilver but then attach the log

Hi I''m running OpenSolaris 148 on a few boxes, and newer boxes are getting installed as we speak. What would you suggest for a good SLOG device? It seems some new PCI-E-based ones are hitting the market, but will those require special drivers? Cost is obviously alsoo an issue here.... Vennlige hilsener / Best regards roy -- Roy Sigurd Karlsbakk (+47) 97542685 roy at karlsbakk.net

I have historically noticed that in ZFS, when ever there is a heavy writer to a pool via NFS, the reads can held back (basically paused). An example is a RAID10 pool of 6 disks, whereby a directory of files including some large 100+MB in size being written can cause other clients over NFS to pause for seconds (5-30 or so). This on B70 bits. I''ve gotten used to this behavior over NFS, but