I've today set up a new fileserver using EON 0.600 (based on SNV130). I'm now
copying files between mirrors, and the performance is slower than I had hoped.
I am trying to figure out what to do to make things a bit faster in terms of
performance. Thanks in advance for reading, and sharing any thoughts you might
have.
SYstem (brand new today): Dell Poweredge T410. Intel Xeon E5504 5.0 GHz (Core
i7-based) with 4 GB of RAM. I have one zpool of four 2-TB Hitachi Deskstar SATA
drives. I used the SATA mode on the motherboard (not the RAID mode, because I
don't want the motherboard's RAID controller to do something funny to the
drives). Everything gets recognized, and the EON storage "install" was just
fine.
I then configured the drives into an array of two mirrors, made with zpool
create mirror (drives 1 and 2), then zpool add mirror (drives 3 and 4).
The output from zpool status is:
state: ONLINE
scrub: none requested
config:
NAME STATE READ WRITE CKSUM
hextb_data ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
c1d0 ONLINE 0 0 0
c1d1 ONLINE 0 0 0
mirror-1 ONLINE 0 0 0
c2d0 ONLINE 0 0 0
c2d1 ONLINE 0 0 0
This is a 4TB array, initially empty, that I want to copy data TO.
I then added two more 2 TB drives that were an existing pool on an older
machine. I want to move about 625 GB of deduped data from the old pool (the
simple mirror of two 2 TB drives that I physically moved over) to the new pool.
The case can accommodate all six drives.
I snapshotted the old data on the 2 TB array, and made a new filesystem on the
4 TB array. I then moved the data over with:
zfs send -RD data_on_old_p...@snapshot | zfs recv -dF data_on_new_pool
Here's the problem. When I run "iostat -xn", I get:
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
70.0 0.0 6859.4 0.3 0.2 0.2 2.1 2.4 5 10 c3d0
69.8 0.0 6867.0 0.3 0.2 0.2 2.2 2.4 5 10 c4d0
20.0 68.0 675.1 6490.6 0.9 0.6 10.0 6.6 22 32 c1d0
19.5 68.0 675.4 6490.6 0.9 0.6 10.1 6.7 22 33 c1d1
19.0 67.2 669.2 6492.5 1.2 0.7 13.8 7.8 28 36 c2d0
20.2 67.1 676.8 6492.5 1.2 0.7 13.9 7.8 28 37 c2d1
The OLD pool is the mirror of c3d0 and c4d0. The NEW pool is the striped set of
mirrors involving c1d0, c1d1, c2d0 and c2d1.
The transfer started out a few hours ago at about 3 MB/sec. Now it's nearly 7
MB/sec. But why is this so low? Everything is deduped and compressed. And it's
an internal transfer, within the same machine, from one set of hard drives to
another, via the SATA controller. Yet the net effect is very slow. I'm trying
to figure out what this is, since it's much slower than I would have hoped.
Any and all advice on what to do to troubleshoot and fix the problem would be
quite welcome. Thanks!
--
This message posted from opensolaris.org
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
