Hello Wee, Sunday, April 22, 2007, 11:25:23 AM, you wrote:
WYT> On 4/20/07, Robert Milkowski <[EMAIL PROTECTED]> wrote: >> Hello Wee, >> >> Friday, April 20, 2007, 5:20:00 AM, you wrote: >> >> WYT> On 4/20/07, Robert Milkowski <[EMAIL PROTECTED]> wrote: >> >> You can limit how much memory zfs can use for its caching. >> >> >> >> WYT> Indeed, but that memory will still be locked. How can you tell the >> WYT> system to be "flexible" with the caching? >> >> It shouldn't be locked but in reality it can. WYT> It will be "locked" because there is nothing in its view that is WYT> claiming memory. The machine is a file server and does very little WYT> else that demands memory. cachelist will lose to zio_buffer. >> I don't know how SAM-FS works (I've never used it) but I'm surprised >> that you started paging via using swap - or perhaps you meant >> something else.t >> >> If qfs uses standard page cache perhaps increasing segmap would also >> help. It's still static however. WYT> How do you increase segmap? bash-3.00# mdb -k Loading modules: [ unix krtld genunix dtrace specfs ufs sd pcisch md ip sctp usba fcp fctl qlc ssd crypto lofs zfs random ptm cpc nfs ] > segmap_percent/D segmap_percent: segmap_percent: 12 (it's static IIRC) >> By limit ZFS arc you are not disabling prefetching or any other >> features. >> >> First I would be most interested what exactly happened when your >> server started to crawl 'coz you can't "swap out" page cache or arc >> cache... WYT> It wasn't a case of swapping. In fact, the problem is exactly the WYT> reverse. There was not enough memory demand to kick ARC to scale back WYT> on its memory usage. In our test runs with ZFS serving as copy1 for WYT> SAMFS, we saw ZFS using up 1.5-2GB of RAM even when the system is WYT> idle. The cache is leftover from the previous archiving activities WYT> and is unlikely to be reused. I'd rather the memory be used by SAMFS. Then limit the arc size (see list archives on how to do it). -- Best regards, Robert mailto:[EMAIL PROTECTED] http://milek.blogspot.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
