Date: Wed, 22 Jul 2009 09:01:00 +0200 From: Mark Stapper <stark@mapper.nl> To: Arnaud Houdelette <arnaud.houdelette@tzim.net> Cc: stable@freebsd.org Subject: Re: ZFS RAIDZ and atacontrol spindown settings Message-ID: <4A66B92C.8000800@mapper.nl> In-Reply-To: <4A65CE7F.8040906@tzim.net> References: <4A643F5B.8080806@mapper.nl> <h421n2$1kt$1@ger.gmane.org> <4A656076.2060205@mapper.nl> <9bbcef730907210137udf7f90ax21aa530ab859f8a6@mail.gmail.com> <4A658205.5000709@mapper.nl> <4A65CE7F.8040906@tzim.net>
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This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig79AF0E98F90AACF67708881F Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Arnaud Houdelette wrote: > Mark Stapper a =C3=A9crit : >> Ivan Voras wrote: >> =20 >>> 2009/7/21 Mark Stapper <stark@mapper.nl>: >>> =20 >>>> Ivan Voras wrote: >>>> =20 >>>>> Mark Stapper wrote: >>>>> =20 >>>>>> Good day, >>>>>> >>>>>> I am the proud user of a FreeBSD 7.2 AMD64 system housing, >>>>>> amongst other >>>>>> things, a data server. >>>>>> My "server"(It's called "Yoshi") runs FreeBSD from a mirrored syst= em >>>>>> disc, and has a zfs RAIDZ array with 4 discs for bulky data. >>>>>> As it is a home server, and I work during the day, these four >>>>>> discs were >>>>>> spinning happily all day long without much use for them doing so. >>>>>> To save the world(and money) I issued the command "atacontrol >>>>>> spindown >>>>>> 1800" for all the discs in my array spinning them down after thirt= y >>>>>> minutes of idle spinning. >>>>>> So far so good, me very happy! However, when I access the array >>>>>> after >>>>>> the discs have been spun down, it spins up the discs one after the= >>>>>> other... >>>>>> Mind you one AFTER the other, taking 4*9 seconds to do a "ls" >>>>>> command on >>>>>> my music directory. >>>>>> Content as I am with the smooth down- and upspinning of the disks,= I >>>>>> would like it better if the four discs would spin up simultaneousl= y. >>>>>> Thus my question: "Is it possible to \"group\" discs to be spun u= p >>>>>> together, or to issue a custom command upon upspinning of a disc >>>>>> such as >>>>>> to spin up other disks?" >>>>>> =20 >>>>> Good question but the answer is probably no - it really only depend= s >>>>> on how ZFS accesses the drives; if it accesses them in sequence, yo= u >>>>> can't change it. >>>>> =20 >>>> I've been looking at writing a shell script which monitors >>>> /var/log/messages. >>>> something like: >>>> >>>> If last line in /var/log/messages is like "request while spun down. >>>> Starting." >>>> spinup disks >>>> >>>> couple of problems though, I should probably poll the kernel message= s >>>> every second or so, but if I only check the last linee, I could >>>> miss the >>>> spinup message. >>>> I could count the number of lines in /var/log/messages and keep >>>> count of >>>> the number of lines i've seen. Problem with this approach is that it= 's >>>> not very efficient. >>>> So I was hoping there is a way to receive this kernel message >>>> directly. >>>> I am now thinking in the lines of a program which received a signal = on >>>> new kernel messages available or something similar. >>>> >>>> Any thoughts? >>>> =20 >>> You could do what "tail -f" does and simply hook a kqueue to get new >>> messages from the /var/log/messages file. >>> =20 >> I'll try that! thanks! >> >> =20 > As I get quite the same issue with a 4 disk raidz pool, could you > please tell me the result of your tries ? which command do you use to > force the disks to spin up ? > > Thanks I have been using a shell script containing: #!/bin.sh dd if=3D/dev/ad4 of=3D/dev/null count=3D1& dd if=3D/dev/ad6 of=3D/dev/null count=3D1& dd if=3D/dev/ad8 of=3D/dev/null count=3D1& dd if=3D/dev/ad10 of=3D/dev/null count=3D1& --------------enig79AF0E98F90AACF67708881F Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkpmuS8ACgkQN9xNqOOVnWBj5ACeJjgg6fTTVNfflIEeMOg2VA+D +yQAn3shYOvrdakN6U9tgjgvmryZMy2P =D8O7 -----END PGP SIGNATURE----- --------------enig79AF0E98F90AACF67708881F--
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