I am considering returning to a traditional disk sub-system made up of a bunch of small (18 or 36 gig) HP or Seagate disks instead of continuing to operate with our EMC Symmetrix system.
Our configuration:
HP-UX 11.0
Progress 8.3D (24 gb database, 80 - 300mb exts.)
MFG/PRO 9.0
N4000 with 6 CPU's
4 ultrafast wide SCSI ports
8 gig RAM
400 - 450 users - all local self-serv clients
EMC Symmetrix - 1 gig of cache
Our biggest performance problem is disk I/O.
When running Glance, we consistently see disk I/O between 90% to 100%. User complaints confirm this.
We've had EMC technicians look at their side of the system a half dozen times. They've identified some "slightly hot" areas, and suggested moving a couple of file systems, but stated over all I/O is fairly evenly distributed accross all 4 channels running from the HP server to the EMC box. From the EMC side, nothing is at 100%, and everything is performing very well!!!
The RAM usage of our databases is very close (1.72gig) to the 1.75 gig ceiling of RAM consumption for 32-bit apps on HP-UX. (This was confirmed by an HP performance expert).
My experience:
Before we used EMC for our disk sub-system, we used a bunch of plain old mirrored 18 gig HP disks and stripped the disks while creating one large volume group, and then distributed the database extents evenly across multiple LV's within the large volume group. (BI & AI got their own disks).
Whenever I would do a dump & load (whether dictionary, binary or bulkload) I could complete the whole thing in 24 hours or less.
When we went to EMC, it would take me 48 hours or more to do the same thing, and index rebuilds were excruciatingly painful !!!
Recently, while doing a dump & load, I dumped to, and loaded from, a large vol. group of 6-18 gig HP disks. I also used this same vol group as my sort area for the index rebuilds.
The database that I was dumping from/loading to was on EMC, but most of the heavy I/O was occurring against the HP disks. The whole dump & load time was back down to a little over 24 hours.
Our HP performance consultant stated that he has had other clients complain that dump & loads are MUCH, MUCH slower on EMC vs disks such as HP or Seagate.
Apparent facts:
- Dump & Loads are almost 100% disk I/O.
- Our biggest performance problem is disk I/O.
- Dump & Loads are MUCH faster on "just a buch of disks" than on EMC.
- HP disks are very, very cheap.
- EMC is very, very, expensive.
Conclusion:
I should get rid of EMC and get a bunch of cheap disks (mirrored of course, maybe even 3-ways).
Any thoughts/suggestions/experiences from anyone about this situaiton would be greatly appreciated!!
Our configuration:
HP-UX 11.0
Progress 8.3D (24 gb database, 80 - 300mb exts.)
MFG/PRO 9.0
N4000 with 6 CPU's
4 ultrafast wide SCSI ports
8 gig RAM
400 - 450 users - all local self-serv clients
EMC Symmetrix - 1 gig of cache
Our biggest performance problem is disk I/O.
When running Glance, we consistently see disk I/O between 90% to 100%. User complaints confirm this.
We've had EMC technicians look at their side of the system a half dozen times. They've identified some "slightly hot" areas, and suggested moving a couple of file systems, but stated over all I/O is fairly evenly distributed accross all 4 channels running from the HP server to the EMC box. From the EMC side, nothing is at 100%, and everything is performing very well!!!
The RAM usage of our databases is very close (1.72gig) to the 1.75 gig ceiling of RAM consumption for 32-bit apps on HP-UX. (This was confirmed by an HP performance expert).
My experience:
Before we used EMC for our disk sub-system, we used a bunch of plain old mirrored 18 gig HP disks and stripped the disks while creating one large volume group, and then distributed the database extents evenly across multiple LV's within the large volume group. (BI & AI got their own disks).
Whenever I would do a dump & load (whether dictionary, binary or bulkload) I could complete the whole thing in 24 hours or less.
When we went to EMC, it would take me 48 hours or more to do the same thing, and index rebuilds were excruciatingly painful !!!
Recently, while doing a dump & load, I dumped to, and loaded from, a large vol. group of 6-18 gig HP disks. I also used this same vol group as my sort area for the index rebuilds.
The database that I was dumping from/loading to was on EMC, but most of the heavy I/O was occurring against the HP disks. The whole dump & load time was back down to a little over 24 hours.
Our HP performance consultant stated that he has had other clients complain that dump & loads are MUCH, MUCH slower on EMC vs disks such as HP or Seagate.
Apparent facts:
- Dump & Loads are almost 100% disk I/O.
- Our biggest performance problem is disk I/O.
- Dump & Loads are MUCH faster on "just a buch of disks" than on EMC.
- HP disks are very, very cheap.
- EMC is very, very, expensive.
Conclusion:
I should get rid of EMC and get a bunch of cheap disks (mirrored of course, maybe even 3-ways).
Any thoughts/suggestions/experiences from anyone about this situaiton would be greatly appreciated!!