SomeBody in Netapp Needs to look at this !
-----Original Message----- From: Ambrose_Earle@shamrockfoods.com [mailto:Ambrose_Earle@shamrockfoods.com] Sent: Tuesday, December 10, 2002 9:00 PM To: Kumar, Rahul Cc: toasters@mathworks.com Subject: Re: Dump issue
We are seeing very similar performance issues from our F840Cs. We have opened a case with NetApps, but have received very little information back from them.
In our case, a 3 drive volume backing up gzip'ed files maxes out our SDLT drives at nearly 11 MB/sec. We have a 6 drive volume of highly compressible information that will stream to tape at over 20 MB/sec. However, a 7 drive volume that only contains a few dozen very large Oracle datafiles, now at times struggles to write 4 MB/sec!
The only correlation that I can make is that when disk utilization goes above 40%, the backup speed plummets below 10 MB/sec. Have you tried running sysstat or statit during the backup?
My biggest concern is that this may be the first symptom of some major problem. If 7 drives can't read faster than 4MB/sec, then wouldn't you be a little worried?
As others have suggested, this must be due to network congestion or a *very* large number of files/inodes in the volume.
I've been testing a new customer implementation today and just saw 80MB/sec from an F840, backing up 3 volumes to 3 fibre attached IBM LTOs in parallel. We getting aggregate throughputs of up to 180GB/hr. DOT version is 6.1R3.
The data is a mix of database and many small files.
How many spindles are your volumes striped over ?
D # ----- Original Message ----- From: "Kumar, Rahul" rahul.kumar@eds.com To: Ambrose_Earle@shamrockfoods.com Cc: toasters@mathworks.com Sent: Tuesday, December 10, 2002 3:40 PM Subject: RE: Dump issue
SomeBody in Netapp Needs to look at this !
-----Original Message----- From: Ambrose_Earle@shamrockfoods.com [mailto:Ambrose_Earle@shamrockfoods.com] Sent: Tuesday, December 10, 2002 9:00 PM To: Kumar, Rahul Cc: toasters@mathworks.com Subject: Re: Dump issue
We are seeing very similar performance issues from our F840Cs. We have opened a case with NetApps, but have received very little information back from them.
In our case, a 3 drive volume backing up gzip'ed files maxes out our SDLT drives at nearly 11 MB/sec. We have a 6 drive volume of highly compressible information that will stream to tape at over 20 MB/sec. However, a 7 drive volume that only contains a few dozen very large Oracle datafiles, now at times struggles to write 4 MB/sec!
The only correlation that I can make is that when disk utilization goes above 40%, the backup speed plummets below 10 MB/sec. Have you tried running sysstat or statit during the backup?
My biggest concern is that this may be the first symptom of some major problem. If 7 drives can't read faster than 4MB/sec, then wouldn't you be a little worried?
--- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.419 / Virus Database: 235 - Release Date: 13/11/2002
-
Duncan Greenwood -
Kumar, Rahul