search for: arc_buf_t

I?m trying to understand the inner workings of the adaptive replacement cache (arc). I see there are arc_bufs and arc_buf_hdrs. Each arc_buf_hdr points to an arc_buf_t. The arc_buf_t is really one entry in a list of arc_buf_t entries. The multiple entries are accessed through the arc_buf_t?s b_next member. Why does the arc_buf_hdr point to a list of arc_buf_ts and not just one arc_buf_t, i.e., how and why do multiple arc_buf_ts get inserted into this list? What...

...h I do. I using it for ARC layer. Even with this in place under heavy load the kernel panics, because memory with KM_SLEEP cannot be allocated. Here are some statistics of memory usage when the panic occurs: zfs_znode_cache: 356 * 11547 = 4110732 bytes zil_lwb_cache: 176 * 43 = 7568 bytes arc_buf_t: 20 * 7060 = 141200 bytes arc_buf_hdr_t: 188 * 7060 = 1327280 bytes dnode_t: 756 * 162311 = 122707116 bytes !! dmu_buf_impl_t: 332 * 18649 = 6191468 other: 14432256 bytes (regular kmem_alloc()) There is 1GB of RAM, 320MB is for the kernel. 1/3 if kernel memory is configured a...

Hello. We''re currently using a Sun Blade1000 (2x750MHz, 1G ram, 2x160MB/s mpt scsi buses, skge GigE network) as a NFS backend with ZFS for distribution of free software like Debian (cdimage.debian.org, ftp.se.debian.org) and have run into some performance issues. We are running SX snv_48 and have run with a raidz2 with 7x300G for a while now, just added another 7x300G raidz2 today but

...ail ------------------------- ------ ------ ------ --------- --------- ----- ... dmu_buf_impl_t 192 2029 104328 20348928 326434 0 dnode_t 388 1529 84090 34443264 157309 0 arc_buf_hdr_t 92 13276 26460 2580480 140047 0 arc_buf_t 20 957 5915 143360 225786 0 zil_lwb_cache 184 3 44 8192 149 0 zfs_znode_cache 104 1226 83460 8765440 142715 0 ... Note that the dmu_buf_impl_t, dnode_t and zfs_znode_cache kmem_caches are sitting on...

Has anyone else noticed a significant zfs performance deterioration when running recent opensolaris bits? My 32-bit / 768 MB Toshiba Tecra S1 notebook was able to do a full opensolaris release build in ~ 4 hours 45 minutes (gcc shadow compilation disabled; using an lzjb compressed zpool / zfs on a single notebook hdd p-ata drive). After upgrading to 2007-05-25 opensolaris release bits