So I was looking into the boot flash feature of the newer x4540, and evidently it is simply a CompactFlash slot, with all of the disadvantages and limitations of that type of media. The sun deployment guide recommends minimizing writes to a CF boot device, in particular by NFS mounting /var from a different server, disabling swap or swapping to a different device, and doing all logging over the network. Not exactly a configuration I would prefer. My sales SE said most people weren't utilizing the CF boot feature. The concept is nice, but an implementation with SSD quality flash rather than basic CF (also, preferably redundant devices) would have been better.
If I had an x4540 (which I don't, unfortunately, we picked up a half dozen x4500's just before they were end of sale'd), what I think would be interesting to do would be install two of the 32GB SSD disks in the boot slots, use a 1-5GB sliced mirror as a slog, and the remaining 27-31GB as a sliced mirrored root pool. From what I understand you don't need very much space for an effective slog, and SSD's don't have the write failure limitations of CF. Also, the recommendation for giving ZFS entire discs rather than slices evidently isn't applicable to SSD's as they don't have a write cache. It seems this approach would give you a blazing fast slog, as well as a redundant boot mirror without having to waste an additional two SATA slots. If anybody would like to donate an x4540 to a budget stricken California State University I'd be happy to test it out and report back ;). Given we just found out today that the entire summer quarter schedule of classes has been canceled due to budget cuts :(, I don't see new hardware in our future anytime soon <sigh>... -- Paul B. Henson | (909) 979-6361 | http://www.csupomona.edu/~henson/ Operating Systems and Network Analyst | hen...@csupomona.edu California State Polytechnic University | Pomona CA 91768 _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
