RAID

Los Angeles1
Los Angeles1 used Ask the Experts™
on
Are there RAID's available with HIGE amounts of battery backed cache in order to increase performance with write back mode,
Comment
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
Distinguished Expert 2017
Commented:
What high or huge numbers do you have in mind?
Hp has raid controllers with 2GB of memory.

P421
Which drives sas, sata will be in used the array?

There is a drawback to a large cache since it has to be written back on power failure.
512MB and 1GB are fairly standard.  Some larger cards can go to 2GB.

If you need more than that, consider a RAID controller that will take an SSD and assign it to a caching role.  I saw some LSI MegaRAID cards that do that.  They brand it "CacheCade".

We ended up going with a straight SSD for apps (200-300+MB/sec) and left data on HDD arrays where 120MB/sec was enough.
Top Expert 2015

Commented:
write-back has nothing to do with battery cache.

write back cache means storing written data in cache for reuse - sometimes good sometimes useless...

Write cache of 2GB will not fix slow write speed of RAID5
Well the answer is yes!    There are RAID systems out there with 512GB+ of cache.

But what do you really want to do?

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial