We're getting a bit tight on space, and I'd like to add a drive shelf to my F740.
Right now, we have 2 full shelves of 18gig drives, with 1 for parity and 1 for hot spare. What I had planned to do was get a shelf of 36gig drives, and create a second raid group, then add it to the existing volume.
As I understand it, I would then have 2 hot spares (18 and 36), and two drives for parity.
Are there any "gotchas" (or blatant ignorance on my part) in this scenario?
Thanks, Jordan
As I understand it, I would then have 2 hot spares (18 and 36), and two drives for parity.
Yup.
You would need the separate spare to accomodate the difference in drive sizes. The parity drive is a function of RAID 4.
We did the same about a year back on our 740 and it worked well.
Are there any "gotchas" (or blatant ignorance on my part) in this scenario?
It was mostly smooth. Though you might need to upgrade your ONTAP version to 6.1.1R2 atleast
/dev/null
devnull@adc.idt.com
After reading further in my manuals, I've got some questions about the RAIDgroup size.
When I initially created the volume, I made the raidsize 14, so that it would use 1 parity disk for the 14 disks we had at that time.
Looking at it now, I kind of think that I want a raidsize of 13 for the current volume (since one disk is a hot spare).
So, I issued: vol options vol0 raidsize 13
That worked ok, because now:
vol status vol0
Volume State Status Options vol0 online normal root, raidsize=13 raid group 0: normal
Basically, what I'm trying to avoid here is having the first 36gig disk added to the initial raidgroup. I believe changing the raidsize to 13 will have fixed that, since now that raidgroup is full, and additional disks will go into their own raidgroup.
I welcome (and request. :) all comments on this post.
Thanks very much, Jordan Share
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com]On Behalf Of devnull@adc.idt.com Sent: Wednesday, February 12, 2003 11:28 AM To: Jordan Share Cc: 'Toasters@Mathworks.Com' Subject: Re: Adding a drive shelf to my existing F740
As I understand it, I would then have 2 hot spares (18 and 36), and two drives for parity.
Yup.
You would need the separate spare to accomodate the difference in drive sizes. The parity drive is a function of RAID 4.
We did the same about a year back on our 740 and it worked well.
Are there any "gotchas" (or blatant ignorance on my part) in
this scenario? It was mostly smooth. Though you might need to upgrade your ONTAP version to 6.1.1R2 atleast
/dev/null
devnull@adc.idt.com
First : to be sure we speak the same language (I'm french) the raidsize include the parity disk. a group raid of sized 14 can contain up to 13 data disks and one parity disk. the max size of a raid can be 28
- the more disk in a raid you have, the more the filer need time to reconstruct the disk (and the longer the CPU is used for that). - larger the disk is, the more it consume time also. for exemple, a F760 with a cpu load average at 40% in production can go up to 50% during 6 hours to reconstruct a 72G disk
1 - taking this into account, I won't advise you to move your raidsize to 28, but if you want to save as many as possible disk, you can turn the raidsize to 28 and add those 36G disks in the same raidgroup than other (18G) 2 - there is an extra trick to save a spare disk : don't keep two but only one spare disks : a 36G one, as Filer can reconstruct a 18G broken disk on a 36G. BUT you have to order Netapp for a 36G after that failure. If you have a hardware contract with Netapp, take care because, when a 18G fail, they would send you a 18G too, not a 36G. You would have to check for that (look for a special deal ?)
These two tricks apart, I can't see better ways than what you had plained
Jordan Share wrote:
After reading further in my manuals, I've got some questions about the RAIDgroup size.
When I initially created the volume, I made the raidsize 14, so that it would use 1 parity disk for the 14 disks we had at that time.
Looking at it now, I kind of think that I want a raidsize of 13 for the current volume (since one disk is a hot spare).
So, I issued: vol options vol0 raidsize 13
That worked ok, because now:
vol status vol0
Volume State Status Options vol0 online normal root, raidsize=13 raid group 0: normalBasically, what I'm trying to avoid here is having the first 36gig disk added to the initial raidgroup. I believe changing the raidsize to 13 will have fixed that, since now that raidgroup is full, and additional disks will go into their own raidgroup.
I welcome (and request. :) all comments on this post.
Thanks very much, Jordan Share
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com]On Behalf Of devnull@adc.idt.com Sent: Wednesday, February 12, 2003 11:28 AM To: Jordan Share Cc: 'Toasters@Mathworks.Com' Subject: Re: Adding a drive shelf to my existing F740
As I understand it, I would then have 2 hot spares (18 and 36), and two drives for parity.
Yup.
You would need the separate spare to accomodate the difference in drive sizes. The parity drive is a function of RAID 4.
We did the same about a year back on our 740 and it worked well.
Are there any "gotchas" (or blatant ignorance on my part) in
this scenario? It was mostly smooth. Though you might need to upgrade your ONTAP version to 6.1.1R2 atleast
/dev/null
devnull@adc.idt.com
2 - there is an extra trick to save a spare disk : don't keep two but only one spare disks : a 36G one, as Filer can reconstruct a 18G broken disk on a 36G. BUT you have to order Netapp for a 36G after that failure. If you have a hardware contract with Netapp, take care because, when a 18G fail, they would send you a 18G too, not a 36G. You would have to check for that (look for a special deal ?)
To add to your trick #2, Don't worry about getting a 18GB back from Netapp and leaving your 36 acting like a 18. Simply add the 18 in the place of the failed 18 and let the filer take it as a spare. Then do a disk fail on the 36 acting as a 18. The filer will now look for a spare 18 and find the new spare to rebuild the raid group. Then do a disk unfail on the 36 acting as a 18 and Ontap will zero the 36 and put it back as a 36 spare. So you don't need to work out a special deal with Netapp. I have done this many times and with great success.
----- Original Message ----- From: "Stephane Bentebba" stephane.bentebba@fps.fr To: "Jordan Share" iso9@jwiz.org Cc: "'Toasters@Mathworks.Com'" toasters@mathworks.com Sent: Thursday, February 13, 2003 6:12 AM Subject: Re: Adding a drive shelf to my existing F740
First : to be sure we speak the same language (I'm french) the raidsize include the parity disk. a group raid of sized 14 can contain up to 13 data disks and one parity disk. the max size of a raid can be 28
- the more disk in a raid you have, the more the filer need time to
reconstruct the disk (and the longer the CPU is used for that).
- larger the disk is, the more it consume time also.
for exemple, a F760 with a cpu load average at 40% in production can go up to 50% during 6 hours to reconstruct a 72G disk
1 - taking this into account, I won't advise you to move your raidsize to 28, but if you want to save as many as possible disk, you can turn the raidsize to 28 and add those 36G disks in the same raidgroup than other (18G) 2 - there is an extra trick to save a spare disk : don't keep two but only one spare disks : a 36G one, as Filer can reconstruct a 18G broken disk on a 36G. BUT you have to order Netapp for a 36G after that failure. If you have a hardware contract with Netapp, take care because, when a 18G fail, they would send you a 18G too, not a 36G. You would have to check for that (look for a special deal ?)
These two tricks apart, I can't see better ways than what you had plained
Jordan Share wrote:
After reading further in my manuals, I've got some questions about the RAIDgroup size.
When I initially created the volume, I made the raidsize 14, so that it would use 1 parity disk for the 14 disks we had at that time.
Looking at it now, I kind of think that I want a raidsize of 13 for the current volume (since one disk is a hot spare).
So, I issued: vol options vol0 raidsize 13
That worked ok, because now:
vol status vol0
Volume State Status Options vol0 online normal root, raidsize=13 raid group 0: normalBasically, what I'm trying to avoid here is having the first 36gig disk added to the initial raidgroup. I believe changing the raidsize to 13
will
have fixed that, since now that raidgroup is full, and additional disks
will
go into their own raidgroup.
I welcome (and request. :) all comments on this post.
Thanks very much, Jordan Share
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com]On Behalf Of devnull@adc.idt.com Sent: Wednesday, February 12, 2003 11:28 AM To: Jordan Share Cc: 'Toasters@Mathworks.Com' Subject: Re: Adding a drive shelf to my existing F740
As I understand it, I would then have 2 hot spares (18 and 36), and two drives for parity.
Yup.
You would need the separate spare to accomodate the difference in drive sizes. The parity drive is a function of RAID 4.
We did the same about a year back on our 740 and it worked well.
Are there any "gotchas" (or blatant ignorance on my part) in
this scenario? It was mostly smooth. Though you might need to upgrade your ONTAP
version
to 6.1.1R2 atleast
/dev/null
devnull@adc.idt.com
Jonathan wrote:
2 - there is an extra trick to save a spare disk : don't keep two but only one spare disks : a 36G one, as Filer can reconstruct a 18G broken disk on a 36G. BUT you have to order Netapp for a 36G after that failure. If you have a hardware contract with Netapp, take care because, when a 18G fail, they would send you a 18G too, not a 36G. You would have to check for that (look for a special deal ?)
To add to your trick #2, Don't worry about getting a 18GB back from Netapp and leaving your 36 acting like a 18. Simply add the 18 in the place of the failed 18 and let the filer take it as a spare. Then do a disk fail on the 36 acting as a 18. The filer will now look for a spare 18 and find the new spare to rebuild the raid group. Then do a disk unfail on the 36 acting as a 18 and Ontap will zero the 36 and put it back as a 36 spare. So you don't need to work out a special deal with Netapp. I have done this many times and with great success.
of course ! i knew it indeed, what a dumb I am :) you have to switch mode in order to use disk unfail : use " rc_toggle_basic " or " priv set advanced / admin"
----- Original Message ----- From: "Stephane Bentebba" stephane.bentebba@fps.fr To: "Jordan Share" iso9@jwiz.org Cc: "'Toasters@Mathworks.Com'" toasters@mathworks.com Sent: Thursday, February 13, 2003 6:12 AM Subject: Re: Adding a drive shelf to my existing F740
First : to be sure we speak the same language (I'm french) the raidsize include the parity disk. a group raid of sized 14 can contain up to 13 data disks and one parity disk. the max size of a raid can be 28
- the more disk in a raid you have, the more the filer need time to
reconstruct the disk (and the longer the CPU is used for that).
- larger the disk is, the more it consume time also.
for exemple, a F760 with a cpu load average at 40% in production can go up to 50% during 6 hours to reconstruct a 72G disk
1 - taking this into account, I won't advise you to move your raidsize to 28, but if you want to save as many as possible disk, you can turn the raidsize to 28 and add those 36G disks in the same raidgroup than other (18G) 2 - there is an extra trick to save a spare disk : don't keep two but only one spare disks : a 36G one, as Filer can reconstruct a 18G broken disk on a 36G. BUT you have to order Netapp for a 36G after that failure. If you have a hardware contract with Netapp, take care because, when a 18G fail, they would send you a 18G too, not a 36G. You would have to check for that (look for a special deal ?)
These two tricks apart, I can't see better ways than what you had plained
Jordan Share wrote:
After reading further in my manuals, I've got some questions about the RAIDgroup size.
When I initially created the volume, I made the raidsize 14, so that it would use 1 parity disk for the 14 disks we had at that time.
Looking at it now, I kind of think that I want a raidsize of 13 for the current volume (since one disk is a hot spare).
So, I issued: vol options vol0 raidsize 13
That worked ok, because now:
vol status vol0
Volume State Status Options vol0 online normal root, raidsize=13 raid group 0: normalBasically, what I'm trying to avoid here is having the first 36gig disk added to the initial raidgroup. I believe changing the raidsize to 13
will
have fixed that, since now that raidgroup is full, and additional disks
will
go into their own raidgroup.
I welcome (and request. :) all comments on this post.
Thanks very much, Jordan Share
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com]On Behalf Of devnull@adc.idt.com Sent: Wednesday, February 12, 2003 11:28 AM To: Jordan Share Cc: 'Toasters@Mathworks.Com' Subject: Re: Adding a drive shelf to my existing F740
As I understand it, I would then have 2 hot spares (18 and 36), and two drives for parity.
Yup.
You would need the separate spare to accomodate the difference in drive sizes. The parity drive is a function of RAID 4.
We did the same about a year back on our 740 and it worked well.
Are there any "gotchas" (or blatant ignorance on my part) in
this scenario? It was mostly smooth. Though you might need to upgrade your ONTAP
version
to 6.1.1R2 atleast
/dev/null
devnull@adc.idt.com
-
devnull＠adc.idt.com -
Jonathan -
Jordan Share -
Stephane Bentebba