Re: very slow sync

"Also sprach Hegedus Gabor:"
> 2005-02-01, k keltez_ssel 16:35-kor Peter T. Breuer ezt _rta:
> > 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

Then that's probably your problem! You might want to change that.


> > 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

You haven't turned on merge requests ...

> [a] Queued:	+0R/0W curr (check 0R/0W) +248R/1024W max
> [a] Buffersize:	262144	(sectors=512, blocks=512)
> [a] Blocksize:	512	(log=9)

And the blocksize is tiny! What? How? That's most unusual. Are you
running xfs or something?

> [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

Yes, well, all the requests coming through are for 1KB or 4KB. I'm not
sure how you chose 512B as blocksize.  I'd simply turn on
merge_requests, rather than change it, since I'm sure you have a good
reason!  Maybe set it to about 128.


Peter