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From: Billy N. <bne...@us...> - 2007-09-17 20:09:01
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----------------- Sent from my BlackBerry Handheld. ----- Original Message ----- From: linux-iscsi-users-request Sent: 09/17/2007 01:05 PM To: lin...@li... Subject: linux-iscsi-users Digest, Vol 14, Issue 1 Send linux-iscsi-users mailing list submissions to lin...@li... To subscribe or unsubscribe via the World Wide Web, visit https://lists.sourceforge.net/lists/listinfo/linux-iscsi-users or, via email, send a message with subject or body 'help' to lin...@li... You can reach the person managing the list at lin...@li... When replying, please edit your Subject line so it is more specific than "Re: Contents of linux-iscsi-users digest..." Today's Topics: 1. Good write bad read times (joshi) 2. Re: Good write bad read times (iscsi) 3. Re: Good write bad read times (Hiren Joshi) 4. Re: Good write bad read times (iscsi) 5. Re: Good write bad read times (Hiren Joshi) ---------------------------------------------------------------------- Message: 1 Date: Mon, 17 Sep 2007 06:35:03 -0700 (PDT) From: joshi <jo...@mo...> Subject: [linux-iscsi-users] Good write bad read times To: lin...@li... Message-ID: <127...@ta...> Content-Type: text/plain; charset=3Dus-ascii Sorry if I've already posted this. This is weird, I have Dell (EMC) Ax150i running centos4.4 2.6.9-42.ELsmp iscsi-initiator-utils-4.0.3.0-5 My write speed (dd about 10GB to the disk) is 250MB/s This is good. My read speed (dd 10GB from the disk to /dev/null) is about 3MB/s Bad =3D( I'm using the default config for iscsid and am at my wits end, can anyone on this list point me in the right direction? Thanks, Josh. -- View this message in context: http://www.nabble.com/Good-write-bad-read-times= -tf4466582.html#a12735484 Sent from the linux-iscsi-users mailing list archive at Nabble.com. ------------------------------ Message: 2 Date: Mon, 17 Sep 2007 13:46:53 -0300 From: iscsi <is...@un...> Subject: Re: [linux-iscsi-users] Good write bad read times To: joshi <jo...@mo...> Cc: lin...@li... Message-ID: <46E...@un...> Content-Type: text/plain; charset=3Dus-ascii; format=3Dflowed how did you measure those values ? e.g 10GB to the disk !!!! have you used any software for this benchmark. joshi wrote: > Sorry if I've already posted this. > > This is weird, I have Dell (EMC) Ax150i running centos4.4 > 2.6.9-42.ELsmp > iscsi-initiator-utils-4.0.3.0-5 > > My write speed (dd about 10GB to the disk) is 250MB/s This is good. > My read speed (dd 10GB from the disk to /dev/null) is about 3MB/s Bad =3D( > > I'm using the default config for iscsid and am at my wits end, can anyone on > this list point me in the right direction? > > Thanks, > Josh. > ------------------------------ Message: 3 Date: Mon, 17 Sep 2007 17:57:52 +0100 From: "Hiren Joshi" <jo...@mo...> Subject: Re: [linux-iscsi-users] Good write bad read times To: "iscsi" <is...@un...> Cc: lin...@li... Message-ID: <372...@mi...eekattic.local> Content-Type: text/plain; charset=3D"us-ascii" I did a basic dd if=3D/dev/zero to the disk then dd to /dev/null from the disk, timing. Also: hdparm -tT /dev/sdc /dev/sdc: Timing cached reads: 4764 MB in 2.00 seconds =3D 2383.55 MB/sec Timing buffered disk reads: 10 MB in 3.46 seconds =3D 2.89 MB/sec Also tried dd if=3D/dev/sdc of=3D/dev/null bs=3D4096 count=3D512.... Tried bonnie++, all tests point to the same thing, that is, I can write 150MB/s but can only read 3MB/s. -----Original Message----- From: lin...@li... [mailto:lin...@li...] On Behalf Of iscsi Sent: 17 September 2007 17:47 To: Hiren Joshi Cc: lin...@li... Subject: Re: [linux-iscsi-users] Good write bad read times how did you measure those values ? e.g 10GB to the disk !!!! have you used any software for this benchmark. joshi wrote: > Sorry if I've already posted this. > > This is weird, I have Dell (EMC) Ax150i running centos4.4 > 2.6.9-42.ELsmp > iscsi-initiator-utils-4.0.3.0-5 > > My write speed (dd about 10GB to the disk) is 250MB/s This is good. > My read speed (dd 10GB from the disk to /dev/null) is about 3MB/s Bad > =3D( > > I'm using the default config for iscsid and am at my wits end, can > anyone on this list point me in the right direction? > > Thanks, > Josh. > ------------------------------------------------------------------------ - This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ linux-iscsi-users mailing list lin...@li... https://lists.sourceforge.net/lists/listinfo/linux-iscsi-users ------------------------------ Message: 4 Date: Mon, 17 Sep 2007 14:01:08 -0300 From: iscsi <is...@un...> Subject: Re: [linux-iscsi-users] Good write bad read times To: Hiren Joshi <jo...@mo...> Cc: lin...@li... Message-ID: <46E...@un...> Content-Type: text/plain; charset=3Dus-ascii; format=3Dflowed are you using RAID 5. I believe RAID 5 Read is less than write. Striping hard drives will improve read and write access. however still speed difference shouldn't be this much. Hiren Joshi wrote: > I did a basic dd if=3D/dev/zero to the disk then dd to /dev/null from the > disk, timing. > > Also: > hdparm -tT /dev/sdc > /dev/sdc: > Timing cached reads: 4764 MB in 2.00 seconds =3D 2383.55 MB/sec > Timing buffered disk reads: 10 MB in 3.46 seconds =3D 2.89 MB/sec > > Also tried dd if=3D/dev/sdc of=3D/dev/null bs=3D4096 count=3D512.... Tried > bonnie++, all tests point to the same thing, that is, I can write > 150MB/s but can only read 3MB/s. > > > -----Original Message----- > From: lin...@li... > [mailto:lin...@li...] On Behalf Of > iscsi > Sent: 17 September 2007 17:47 > To: Hiren Joshi > Cc: lin...@li... > Subject: Re: [linux-iscsi-users] Good write bad read times > > > how did you measure those values ? e.g 10GB to the disk !!!! > have you used any software for this benchmark. > > > > joshi wrote: > >> Sorry if I've already posted this. >> >> This is weird, I have Dell (EMC) Ax150i running centos4.4 >> 2.6.9-42.ELsmp >> iscsi-initiator-utils-4.0.3.0-5 >> >> My write speed (dd about 10GB to the disk) is 250MB/s This is good. >> My read speed (dd 10GB from the disk to /dev/null) is about 3MB/s Bad >> =3D( >> >> I'm using the default config for iscsid and am at my wits end, can >> anyone on this list point me in the right direction? >> >> Thanks, >> Josh. >> >> > > > ------------------------------------------------------------------------ > - > This SF.net email is sponsored by: Microsoft Defy all challenges. > Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > linux-iscsi-users mailing list > lin...@li... > https://lists.sourceforge.net/lists/listinfo/linux-iscsi-users > > ------------------------------ Message: 5 Date: Mon, 17 Sep 2007 18:09:49 +0100 From: "Hiren Joshi" <jo...@mo...> Subject: Re: [linux-iscsi-users] Good write bad read times To: "iscsi" <is...@un...> Cc: lin...@li... Message-ID: <372...@mi...eekattic.local> Content-Type: text/plain; charset=3D"us-ascii" Indeed, 3MB/s tells me something is really wrong some ware. I tried it with a RAID 1 as well, again read is ~=3D3MB/s. I have used 2 servers and both nics on the AX150i, it gives me the same results. -----Original Message----- From: iscsi [mailto:is...@un...] Sent: 17 September 2007 18:01 To: Hiren Joshi Cc: lin...@li... Subject: Re: [linux-iscsi-users] Good write bad read times are you using RAID 5. I believe RAID 5 Read is less than write. Striping hard drives will improve read and write access. however still speed difference shouldn't be this much. Hiren Joshi wrote: > I did a basic dd if=3D/dev/zero to the disk then dd to /dev/null from > the disk, timing. > > Also: > hdparm -tT /dev/sdc > /dev/sdc: > Timing cached reads: 4764 MB in 2.00 seconds =3D 2383.55 MB/sec > Timing buffered disk reads: 10 MB in 3.46 seconds =3D 2.89 MB/sec > > Also tried dd if=3D/dev/sdc of=3D/dev/null bs=3D4096 count=3D512.... Tried > bonnie++, all tests point to the same thing, that is, I can write > 150MB/s but can only read 3MB/s. > > > -----Original Message----- > From: lin...@li... > [mailto:lin...@li...] On Behalf Of > iscsi > Sent: 17 September 2007 17:47 > To: Hiren Joshi > Cc: lin...@li... > Subject: Re: [linux-iscsi-users] Good write bad read times > > > how did you measure those values ? e.g 10GB to the disk !!!! > have you used any software for this benchmark. > > > > joshi wrote: > >> Sorry if I've already posted this. >> >> This is weird, I have Dell (EMC) Ax150i running centos4.4 >> 2.6.9-42.ELsmp >> iscsi-initiator-utils-4.0.3.0-5 >> >> My write speed (dd about 10GB to the disk) is 250MB/s This is good. >> My read speed (dd 10GB from the disk to /dev/null) is about 3MB/s Bad >> =3D( >> >> I'm using the default config for iscsid and am at my wits end, can >> anyone on this list point me in the right direction? >> >> Thanks, >> Josh. >> >> > > > ---------------------------------------------------------------------- > -- > - > This SF.net email is sponsored by: Microsoft Defy all challenges. > Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > linux-iscsi-users mailing list > lin...@li... > https://lists.sourceforge.net/lists/listinfo/linux-iscsi-users > > ------------------------------ ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ ------------------------------ _______________________________________________ linux-iscsi-users mailing list lin...@li... https://lists.sourceforge.net/lists/listinfo/linux-iscsi-users End of linux-iscsi-users Digest, Vol 14, Issue 1 ************************************************ |