On Mon, Dec 12, 2011 at 02:03:13PM +0100, Eugen Leitl wrote: > On Mon, Dec 12, 2011 at 01:55:45PM +0100, Herbert Poetzl wrote: >> On Mon, Dec 12, 2011 at 12:47:55PM +0100, Eugen Leitl wrote: >>> I would like to put a zfs hybrid box I have for vserver >>> production, to improve IOPS of the underlying disks. >> so some kind of raid/pool setup with ssd/memory caches >> or something like that? > Yeah, it's an 8 GByte RAM 4x 1 TByte Solaris box > with an Intel SSD cache. >>> 1) would you use iSCSI or NFS for vserver guests, for >>> better performance and/or flexibility? >> iSCSI will result in 'block' transfers (similar goes for >> AOE) so that requires a filesystem on the client with all >> the filesystem overhead, but it might provide better >> performance for 'certain' workloads > Which workloads in particular? I'm worried about > workloads like IMAP with Maildir. If thens or > hundreds vserver guests are running on a single > machine there bound to be several users fighting > for spindle access at the same time. >>> 2) is just mounting /home e.g. via NFS for each >>> vserver guest a better idea? >> than having the entire guest on NFS? > Yes. >> also, the 'zfs hybrid box' is a different machine than >> the one running the guests? > Yes. Connected via GBit Ethernet. I can enable jumbo > frames. so, what performance do you get over this setup ignoring any filesystem overhead? 50MB/s 100MB/s ? how many packets (I/O operations) can you transmit in a second? 10k? 20k? ... I guess a single SSD, attached via SATA 6GB locally will seriously outperform whatever solution you have in mind, but of course, you cannot share that between different hosts easily best, Herbert >> please clarify the setup, otherwise it's mostly hand >> waving and probably useless for your setup > Thanks, the questions you've asked are helping me already. > -- > Eugen* Leitl <a href="leitlhttp://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