Re: [zfs-discuss] SSD (SLC) for cache...
Thanks Adam, So, if i understand well, the MLC SSD more appropriate for read cache is more theory than pratice right now. Right? I mean, SUN is just using SLC SSD's? That would explain the only support for SLC on SUN hardware (x42xx) series. Thanks again. Leal [ http://www.eall.com.br/blog ] -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] SSD (SLC) for cache...
My question is about SSD, and the differences between use SLC for readzillas instead of MLC. Sun uses MLCs for Readzillas for their 7000 series. I would think that if SLCs (which are generally more expensive) were really needed, they would be used. That's not entirely accurate. In the 7410 and 7310 today (the members of the Sun Storage 7000 series that support Readzilla) we use SLC SSDs. We're exploring the use of MLC. Perhaps someone on the Fishworks team could give more details, but by going what I've read and seen, MLCs should be sufficient for the L2ARC. Save your money. That's our assessment, but it's highly dependent on the specific characteristics of the MLC NAND itself, the SSD controller, and, of course, the workload. Adam -- Adam Leventhal, Fishworkshttp://blogs.sun.com/ahl ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] SSD (SLC) for cache...
On Tue, August 11, 2009 09:24, Marcelo Leal wrote: Many companies (including SUN), has just hardware with support to SLC... as i need both, i just want to hear your experiences about use SLC SSD for ZFS cache. One point is cost, but i want to know if the performance is much different, because the two are created specifically to provide better latency for one or another operation. The cost of an SLC SSD is a lot cheaper than trying to get the same performance from purchasing many disks so you have a lot of spindles (you usually have to purchase 15 krpm). Here is one example of some of the performance increases that can be had: http://blogs.sun.com/brendan/entry/slog_screenshots Of course what you get depends on your actual workload. If is not big deal, i will use some hardware (eg.: x4275) using just SLC for readzilas and logs. It would probably be more cost effective to purchase SLC(s) for ZIL logs, but MLC SSD(s) for readzillas. This is what Sun does in their 7000 series storage appliances: http://blogs.sun.com/brendan/entry/l2arc_screenshots Again, what you personally get would depend on workload. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] SSD (SLC) for cache...
On Aug 11, 2009, at 17:07, Marcelo Leal wrote: My question is about SSD, and the differences between use SLC for readzillas instead of MLC. Sun uses MLCs for Readzillas for their 7000 series. I would think that if SLCs (which are generally more expensive) were really needed, they would be used. Perhaps someone on the Fishworks team could give more details, but by going what I've read and seen, MLCs should be sufficient for the L2ARC. Save your money. Of course, SLCs will work just fine, it's just that there's no real advantage. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
