From: Ming Z. <mi...@el...> - 2005-07-26 14:36:34
|
I have a friend asked me for this. I wonder if anybody can give me a recommendation? Many of you are admin who are much better than me on this. :) Thanks! > I have a question for you. I want to use iscsi array > to store database data file. I hope I can get some > kind of redundency (RAID) as well as dynamic increase > disk space without shuting down the database to > rebuild the array. The database will have transactions > all the time and can't be shutdown. Ming |
From: Sander <sa...@hu...> - 2005-07-27 10:46:00
|
Ming Zhang wrote (ao): > I have a friend asked me for this. I wonder if anybody can give me a > recommendation? Many of you are admin who are much better than me on > this. :) > > > I have a question for you. I want to use iscsi array > > to store database data file. I hope I can get some > > kind of redundency (RAID) as well as dynamic increase > > disk space without shuting down the database to > > rebuild the array. The database will have transactions > > all the time and can't be shutdown. If the database _needs_ to run _all_ the time, hey should have a master-slave / hot spare / failover setup. With such a setup, he can enlarge the diskspace of the hot spare slave, fail over, enlarge the diskspace of the former master and make that one the hot spare slave. Of course the iscsi array(s) can be raid. -- Humilis IT Services and Solutions http://www.humilis.net |
From: Ming Z. <mi...@el...> - 2005-07-27 12:16:46
|
On Wed, 2005-07-27 at 12:45 +0200, Sander wrote: > Ming Zhang wrote (ao): > > I have a friend asked me for this. I wonder if anybody can give me a > > recommendation? Many of you are admin who are much better than me on > > this. :) > > > > > I have a question for you. I want to use iscsi array > > > to store database data file. I hope I can get some > > > kind of redundency (RAID) as well as dynamic increase > > > disk space without shuting down the database to > > > rebuild the array. The database will have transactions > > > all the time and can't be shutdown. > > If the database _needs_ to run _all_ the time, hey should have a > master-slave / hot spare / failover setup. With such a setup, he can > enlarge the diskspace of the hot spare slave, fail over, enlarge the > diskspace of the former master and make that one the hot spare slave. > > Of course the iscsi array(s) can be raid. > i am thinking if possible to have mysql + xfs + open-iscsi + iet + lvm + md. so if need larger size, just add another software raid to vg and then do lvextend, then do rescan on iet (need develop), then do a xfs online resize? yes, as u said, if want high availability, we need a master salve here. thx! Ming |
From: Ming Z. <mi...@el...> - 2005-07-27 16:36:51
|
On Thu, 2005-07-28 at 00:24 +0800, Feizhou wrote: > >>>>I have a question for you. I want to use iscsi array > >>>>to store database data file. I hope I can get some > >>>>kind of redundency (RAID) as well as dynamic increase > >>>>disk space without shuting down the database to > >>>>rebuild the array. The database will have transactions > >>>>all the time and can't be shutdown. > >>>> > >>>> > > > >i am thinking if possible to have > >mysql + xfs + open-iscsi + iet + lvm + md. so if need larger size, just > >add another software raid to vg and then do lvextend, then do rescan on > >iet (need develop), then do a xfs online resize? > > > > > > xfs the fs? Ugh. ext3 with data=journal would be better in case of a > crash or what ever. can ext3 do online resize? i am not sure. > > unless you have free hotswap SCSI bays available, adding another > software raid will have to mean another box with iet. but raid5 can not dynamic add disk and expand size right? > > At same blinking time, lvm does not tolerate losing physical volumes so > if a iet box goes down.... iet is on top of lv, so even iet box crash, hopefully lvm is still there. > > very murky this one :P any suggestion? ming |
From: Feizhou <fe...@gr...> - 2005-07-27 16:47:55
|
Ming Zhang wrote: >On Thu, 2005-07-28 at 00:24 +0800, Feizhou wrote: > > >>>>>>I have a question for you. I want to use iscsi array >>>>>>to store database data file. I hope I can get some >>>>>>kind of redundency (RAID) as well as dynamic increase >>>>>>disk space without shuting down the database to >>>>>>rebuild the array. The database will have transactions >>>>>>all the time and can't be shutdown. >>>>>> >>>>>> >>>>>> >>>>>> >>>i am thinking if possible to have >>>mysql + xfs + open-iscsi + iet + lvm + md. so if need larger size, just >>>add another software raid to vg and then do lvextend, then do rescan on >>>iet (need develop), then do a xfs online resize? >>> >>> >>> >>> >>xfs the fs? Ugh. ext3 with data=journal would be better in case of a >>crash or what ever. >> >> >can ext3 do online resize? i am not sure. > > yup. latest centos4.1 does it for example. > > >>unless you have free hotswap SCSI bays available, adding another >>software raid will have to mean another box with iet. >> >> >but raid5 can not dynamic add disk and expand size right? > > > no, hence the need for lvm...but at the same time, lvm does not tolerate disk loss. > > >>At same blinking time, lvm does not tolerate losing physical volumes so >>if a iet box goes down.... >> >> >iet is on top of lv, so even iet box crash, hopefully lvm is still >there. > > > you still need lvm on the database box itself to do dynamic resizing. > > >>very murky this one >> >> > >:P any suggestion? > > i had a hard think on this one...linux lvm don't do fault tolerance but md does...so where do you use these pieces on the initiator box and or the target box and how to combine them is a bit sketchy at the moment. |
From: Ming Z. <mi...@el...> - 2005-07-27 16:52:42
|
On Thu, 2005-07-28 at 00:48 +0800, Feizhou wrote: > Ming Zhang wrote: > > >On Thu, 2005-07-28 at 00:24 +0800, Feizhou wrote: > > > > > >>>>>>I have a question for you. I want to use iscsi array > >>>>>>to store database data file. I hope I can get some > >>>>>>kind of redundency (RAID) as well as dynamic increase > >>>>>>disk space without shuting down the database to > >>>>>>rebuild the array. The database will have transactions > >>>>>>all the time and can't be shutdown. > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>i am thinking if possible to have > >>>mysql + xfs + open-iscsi + iet + lvm + md. so if need larger size, just > >>>add another software raid to vg and then do lvextend, then do rescan on > >>>iet (need develop), then do a xfs online resize? > >>> > >>> > >>> > >>> > >>xfs the fs? Ugh. ext3 with data=journal would be better in case of a > >>crash or what ever. > >> > >> > >can ext3 do online resize? i am not sure. > > > > > yup. latest centos4.1 does it for example. cool. thx > > > > > > >>unless you have free hotswap SCSI bays available, adding another > >>software raid will have to mean another box with iet. > >> > >> > >but raid5 can not dynamic add disk and expand size right? > > > > > > > no, hence the need for lvm...but at the same time, lvm does not tolerate > disk loss. so that is why i am thinking lvm on top of several raid5 or 1 > > > > > > >>At same blinking time, lvm does not tolerate losing physical volumes so > >>if a iet box goes down.... > >> > >> > >iet is on top of lv, so even iet box crash, hopefully lvm is still > >there. > > > > > > > you still need lvm on the database box itself to do dynamic resizing. why? i resize the lv iet exports and then ini side see new size scsi disk. > > > > > > >>very murky this one > >> > >> > > > >:P any suggestion? > > > > > i had a hard think on this one...linux lvm don't do fault tolerance but > md does...so where do you use these pieces on the initiator box and or > the target box and how to combine them is a bit sketchy at the moment. we need a complete solution... |
From: Feizhou <fe...@gr...> - 2005-07-27 17:00:51
|
>>>>unless you have free hotswap SCSI bays available, adding another >>>>software raid will have to mean another box with iet. >>>> >>>> >>>> >>>> >>>but raid5 can not dynamic add disk and expand size right? >>> >>> >>> >>> >>> >>no, hence the need for lvm...but at the same time, lvm does not tolerate >>disk loss. >> >> >so that is why i am thinking lvm on top of several raid5 or 1 > > > where the raid5/1 is composed of devices that are available through iscsi. >>> >>> >>> >>> >>>>At same blinking time, lvm does not tolerate losing physical volumes so >>>>if a iet box goes down.... >>>> >>>> >>>> >>>> >>>iet is on top of lv, so even iet box crash, hopefully lvm is still >>>there. >>> >>> >>> >>> >>> >>you still need lvm on the database box itself to do dynamic resizing. >> >> >why? i resize the lv iet exports and then ini side see new size scsi >disk. > > > > this does not work. you cannot just resize a device. this will drive the kernel/filesystem on the initiator side nuts. >>> >>> >>> >>> >>>>very murky this one >>>> >>>> >>>> >>>> >>>:P any suggestion? >>> >>> >>> >>> >>i had a hard think on this one...linux lvm don't do fault tolerance but >>md does...so where do you use these pieces on the initiator box and or >>the target box and how to combine them is a bit sketchy at the moment. >> >> >we need a complete solution... > > > > which comes down to multiple iet boxes. iet locally raided for redundancy. then the initiator box will have to use raid on multiple iet exported devices and treat those as a PV for the initiator LVM. Adding to the VG will mean adding a set of iet boxes. |
From: Ming Z. <mi...@el...> - 2005-07-27 17:13:00
|
On Thu, 2005-07-28 at 01:01 +0800, Feizhou wrote: > >>>>unless you have free hotswap SCSI bays available, adding another > >>>>software raid will have to mean another box with iet. > >>>> > >>>> > >>>> > >>>> > >>>but raid5 can not dynamic add disk and expand size right? > >>> > >>> > >>> > >>> > >>> > >>no, hence the need for lvm...but at the same time, lvm does not tolerate > >>disk loss. > >> > >> > >so that is why i am thinking lvm on top of several raid5 or 1 > > > > > > > where the raid5/1 is composed of devices that are available through iscsi. > u are talking about distributed iscsi raid. complex enough, my head ran slower now. > >>> > >>> > >>> > >>> > >>>>At same blinking time, lvm does not tolerate losing physical volumes so > >>>>if a iet box goes down.... > >>>> > >>>> > >>>> > >>>> > >>>iet is on top of lv, so even iet box crash, hopefully lvm is still > >>>there. > >>> > >>> > >>> > >>> > >>> > >>you still need lvm on the database box itself to do dynamic resizing. > >> > >> > >why? i resize the lv iet exports and then ini side see new size scsi > >disk. > > > > > > > > > this does not work. you cannot just resize a device. this will drive the > kernel/filesystem on the initiator side nuts. > linux might not support this. but in scsi spec, u 100% can resize a LUN and report to initiator. > >>> > >>> > >>> > >>> > >>>>very murky this one > >>>> > >>>> > >>>> > >>>> > >>>:P any suggestion? > >>> > >>> > >>> > >>> > >>i had a hard think on this one...linux lvm don't do fault tolerance but > >>md does...so where do you use these pieces on the initiator box and or > >>the target box and how to combine them is a bit sketchy at the moment. > >> > >> > >we need a complete solution... > > > > > > > > > which comes down to multiple iet boxes. iet locally raided for > redundancy. then the initiator box will have to use raid on multiple iet > exported devices and treat those as a PV for the initiator LVM. Adding > to the VG will mean adding a set of iet boxes. higher cost. :P if i want a raid5, that means i at least need 3 iet box and the more iscsi disk i want to have, the more boxes i wasted. and also since raid can not resize, add a vg, as u said, i need another SET of iet box. not 1 or 2. a SET. :P ming |
From: Sander <sa...@hu...> - 2005-07-27 20:20:26
|
Ming Zhang wrote (ao): > On Thu, 2005-07-28 at 00:48 +0800, Feizhou wrote: > > i had a hard think on this one...linux lvm don't do fault tolerance > > but md does...so where do you use these pieces on the initiator box > > and or the target box and how to combine them is a bit sketchy at > > the moment. > > we need a complete solution... You do have a complete solution if you build a master/slave setup with (at least) two replicating database servers. You not only can use this for enlarging diskspace, but you need this for database, kernel and hardware upgrades (or failure). It all started with a database which needs 24/7 uptime. You can't solve that with a solution for expanding diskspace for the database alone. -- Humilis IT Services and Solutions http://www.humilis.net |
From: Ming Z. <mi...@el...> - 2005-07-27 20:31:24
|
On Wed, 2005-07-27 at 22:20 +0200, Sander wrote: > Ming Zhang wrote (ao): > > On Thu, 2005-07-28 at 00:48 +0800, Feizhou wrote: > > > i had a hard think on this one...linux lvm don't do fault tolerance > > > but md does...so where do you use these pieces on the initiator box > > > and or the target box and how to combine them is a bit sketchy at > > > the moment. > > > > we need a complete solution... > > You do have a complete solution if you build a master/slave setup with > (at least) two replicating database servers. ic. so master/slave sounds good here. > > You not only can use this for enlarging diskspace, but you need this for > database, kernel and hardware upgrades (or failure). i have interest on dynamic resize and let see what i can find. > > It all started with a database which needs 24/7 uptime. You can't solve > that with a solution for expanding diskspace for the database alone. > ye. thx! |
From: Brian W. <br...@te...> - 2005-07-28 23:02:23
|
I *think* the latest EVMS supports dymanic raid-5 capacity changing on 2.6.? (dunno which version it started at).=20 On Tue, 2005-07-26 at 10:36 -0400, Ming Zhang wrote: > I have a friend asked me for this. I wonder if anybody can give me a > recommendation? Many of you are admin who are much better than me on > this. :)=20 >=20 > Thanks! >=20 >=20 > > I have a question for you. I want to use iscsi array > > to store database data file. I hope I can get some > > kind of redundency (RAID) as well as dynamic increase > > disk space without shuting down the database to > > rebuild the array. The database will have transactions > > all the time and can't be shutdown. >=20 >=20 > Ming >=20 >=20 >=20 >=20 > ------------------------------------------------------- > SF.Net email is sponsored by: Discover Easy Linux Migration Strategies > from IBM. Find simple to follow Roadmaps, straightforward articles, > informative Webcasts and more! Get everything you need to get up to > speed, fast. http://ads.osdn.com/?ad_id=3D7477&alloc_id=3D16492&op=3Dclic= k > _______________________________________________ > Iscsitarget-devel mailing list > Isc...@li... > https://lists.sourceforge.net/lists/listinfo/iscsitarget-devel |
From: Ming Z. <mi...@el...> - 2005-07-28 23:13:44
|
On Tue, 2005-07-26 at 09:59 -0500, Brian Wolfe wrote: > I *think* the latest EVMS supports dymanic raid-5 capacity changing on > 2.6.? (dunno which version it started at). > more detail? u mean raid5 in MD? can that be resize dynamically? i do not know. > On Tue, 2005-07-26 at 10:36 -0400, Ming Zhang wrote: > > I have a friend asked me for this. I wonder if anybody can give me a > > recommendation? Many of you are admin who are much better than me on > > this. :) > > > > Thanks! > > > > > > > I have a question for you. I want to use iscsi array > > > to store database data file. I hope I can get some > > > kind of redundency (RAID) as well as dynamic increase > > > disk space without shuting down the database to > > > rebuild the array. The database will have transactions > > > all the time and can't be shutdown. > > > > > > Ming > > > > > > > > > > ------------------------------------------------------- > > SF.Net email is sponsored by: Discover Easy Linux Migration Strategies > > from IBM. Find simple to follow Roadmaps, straightforward articles, > > informative Webcasts and more! Get everything you need to get up to > > speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click > > _______________________________________________ > > Iscsitarget-devel mailing list > > Isc...@li... > > https://lists.sourceforge.net/lists/listinfo/iscsitarget-devel |
From: Brian W. <br...@te...> - 2005-07-29 12:57:04
|
B.5.4. RAID-4/5 Resizing a RAID-4/5 region follows the same rules and restrictions for resizing a RAID-0 region. Expand a RAID-4/5 region by adding one new object to the region. Shrink a RAID-4/5 region by removing up to N-1 of the current child objects in a region with N objects.=20 See Section B.5.2, "RAID-0" for information about how to perform this function. Like RAID-0, RAID-4/5 regions must be deactivated before they are resized. This is from http://evms.sourceforge.net/user_guide/#raid45 I usually just reccomend installing a second raid5 then expanding the volume to use raid-0 over the two raid-5 sets via LVM2 linear. It all really depends on your needs. Maybe if you were to give me your planned usage scenario for the database I could be of more help. :) Feel free to message me privately if you want to keep the details private. On Thu, 2005-07-28 at 19:13 -0400, Ming Zhang wrote: > On Tue, 2005-07-26 at 09:59 -0500, Brian Wolfe wrote: > > I *think* the latest EVMS supports dymanic raid-5 capacity changing on > > 2.6.? (dunno which version it started at).=20 > >=20 > more detail? >=20 > u mean raid5 in MD? can that be resize dynamically? i do not know. >=20 >=20 >=20 >=20 > > On Tue, 2005-07-26 at 10:36 -0400, Ming Zhang wrote: > > > I have a friend asked me for this. I wonder if anybody can give me a > > > recommendation? Many of you are admin who are much better than me on > > > this. :)=20 > > >=20 > > > Thanks! > > >=20 > > >=20 > > > > I have a question for you. I want to use iscsi array > > > > to store database data file. I hope I can get some > > > > kind of redundency (RAID) as well as dynamic increase > > > > disk space without shuting down the database to > > > > rebuild the array. The database will have transactions > > > > all the time and can't be shutdown. > > >=20 > > >=20 > > > Ming > > >=20 > > >=20 > > >=20 > > >=20 > > > ------------------------------------------------------- > > > SF.Net email is sponsored by: Discover Easy Linux Migration Strategie= s > > > from IBM. Find simple to follow Roadmaps, straightforward articles, > > > informative Webcasts and more! Get everything you need to get up to > > > speed, fast. http://ads.osdn.com/?ad_id=3D7477&alloc_id=3D16492&op=3D= click > > > _______________________________________________ > > > Iscsitarget-devel mailing list > > > Isc...@li... > > > https://lists.sourceforge.net/lists/listinfo/iscsitarget-devel >=20 >=20 >=20 > ------------------------------------------------------- > SF.Net email is Sponsored by the Better Software Conference & EXPO Septem= ber > 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices > Agile & Plan-Driven Development * Managing Projects & Teams * Testing & Q= A > Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf > _______________________________________________ > Iscsitarget-devel mailing list > Isc...@li... > https://lists.sourceforge.net/lists/listinfo/iscsitarget-devel |
From: Ming Z. <mi...@el...> - 2005-07-29 14:46:25
|
On Fri, 2005-07-29 at 07:57 -0500, Brian Wolfe wrote: > B.5.4. RAID-4/5 > Resizing a RAID-4/5 region follows the same rules and restrictions for > resizing a RAID-0 region. Expand a RAID-4/5 region by adding one new > object to the region. Shrink a RAID-4/5 region by removing up to N-1 of > the current child objects in a region with N objects. > > See Section B.5.2, "RAID-0" for information about how to perform this > function. > > Like RAID-0, RAID-4/5 regions must be deactivated before they are > resized. thx for the information. but this is not so useful since it has to be stopped. stop mean downtime. :P ming > > > > This is from http://evms.sourceforge.net/user_guide/#raid45 > > I usually just reccomend installing a second raid5 then expanding the > volume to use raid-0 over the two raid-5 sets via LVM2 linear. > > It all really depends on your needs. Maybe if you were to give me your > planned usage scenario for the database I could be of more help. :) Feel > free to message me privately if you want to keep the details private. > > On Thu, 2005-07-28 at 19:13 -0400, Ming Zhang wrote: > > On Tue, 2005-07-26 at 09:59 -0500, Brian Wolfe wrote: > > > I *think* the latest EVMS supports dymanic raid-5 capacity changing on > > > 2.6.? (dunno which version it started at). > > > > > more detail? > > > > u mean raid5 in MD? can that be resize dynamically? i do not know. > > > > > > > > > > > On Tue, 2005-07-26 at 10:36 -0400, Ming Zhang wrote: > > > > I have a friend asked me for this. I wonder if anybody can give me a > > > > recommendation? Many of you are admin who are much better than me on > > > > this. :) > > > > > > > > Thanks! > > > > > > > > > > > > > I have a question for you. I want to use iscsi array > > > > > to store database data file. I hope I can get some > > > > > kind of redundency (RAID) as well as dynamic increase > > > > > disk space without shuting down the database to > > > > > rebuild the array. The database will have transactions > > > > > all the time and can't be shutdown. > > > > > > > > > > > > Ming > > > > > > > > > > > > > > > > > > > > ------------------------------------------------------- > > > > SF.Net email is sponsored by: Discover Easy Linux Migration Strategies > > > > from IBM. Find simple to follow Roadmaps, straightforward articles, > > > > informative Webcasts and more! Get everything you need to get up to > > > > speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click > > > > _______________________________________________ > > > > Iscsitarget-devel mailing list > > > > Isc...@li... > > > > https://lists.sourceforge.net/lists/listinfo/iscsitarget-devel > > > > > > > > ------------------------------------------------------- > > SF.Net email is Sponsored by the Better Software Conference & EXPO September > > 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices > > Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA > > Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf > > _______________________________________________ > > Iscsitarget-devel mailing list > > Isc...@li... > > https://lists.sourceforge.net/lists/listinfo/iscsitarget-devel |