Re: very slow sync

2005-02-01, k keltezéssel 16:35-kor Peter T. Breuer ezt írta:
> The sync speed is really up to raid1, not anyone else.  I expect you
> have not asked raid1 to go any faster than that.  Look in
> /proc/sys/dev/raid!
hygy@uml-rg-fw2:~$ cat /proc/sys/dev/raid/speed_limit_max 
100000
hygy@uml-rg-fw2:~$ cat /proc/sys/dev/raid/speed_limit_min 
100

I try to create a file on the raid device:
hygy@uml-rg-fw2:~$ dd if=/dev/zero of=proba bs=1M count=450
471859200 bytes transferred in 112,427740 seconds (4197000 bytes/sec)

it is very slow to, the speed on the simple raid array (not the enbd) is
about 40MB/sec.


> None of that means very much to me :-(. What does enbd say? Show the
> output from nbdinfo.
hygy@uml-rg-fw2:~$ cat /proc/nbdinfo 
Device a:	Open 
[a] State:	signed, rw, enabled, validated, plug, acct, last error 0,
lives 0, bp 0
[a] Queued:	+0R/0W curr (check 0R/0W) +248R/1024W max
[a] Buffersize:	262144	(sectors=512, blocks=512)
[a] Blocksize:	512	(log=9)
[a] Size:	512000KB
[a] Blocks:	0
[a] Sockets:	4	(+)	(+)	(+)	(*)
[a] Requested:	1.9644M	(496K)	(491K)	(511K)	(511K)	1.030MR/955.4KW	max 8
[a] Despatched:	1.9644M	(496K)	(491K)	(511K)	(511K)	1.030MR/955.4KW	md5
10.5KW (26 eq, 10.4K ne, 0 dn)
[a] Errored:	0	(0)	(0)	(0)	(0)	0+0
[a] Pending:	0	(0)	(0)	(0)	(0)	0R/0W+0R/0W
[a] B/s now:	0	(0R+0W)
[a] B/s ave:	242K	(127KR+141KW)
[a] B/s max:	6.06M	(6.06MR+4.16MW)
[a] Spectrum:	80%2	19%8
[a] Kthreads:	0	(0 waiting/0 running/1 max)
[a] Cthreads:	4	(+)	(+)	(+)	(+)
[a] Cpids:	4	(3279)	(3280)	(3281)	(3282)
Device b-p:	Closed
hygy@uml-rg-fw2:~$ 


> I don't get a good picture at all ...  you say RAID1.  So you are
> running a raid1 over a loopback device to a local file and a remote enbd
> device?  That's quite a lot of layering.
So. node2 have a simple software raid1 to mirror its hard drives. There
is a remote enbd device (which is a file there) and a local file wich is
mounted with loop to /dev/loop0. And I mirrored /dev/loop0
with /dev/nda.

thanks
bye
 HyGy